Best CBD Oil for High Blood Pressure (Hypertension)

Can CBD help lower high blood pressure, and if so, how? Is there a risk it can raise blood pressure?

  • In a 2017 study, researchers concluded that a single dose of CBD reduced resting blood pressure and the blood pressure response to stress.
  • However, researchers believed that the results were a reflection of CBD’s anti-anxiety and analgesic effects. 
  • Authors of a 2019 study demonstrated that CBD reduced stressful environmental factors when given in the optimal dosage.
  • Given that most of the results from blood pressure-related studies done on CBD have been gathered through tests that involve either healthy volunteers or animals, recent research on ill human subjects is still lacking.
  • The American Heart Association (AHA) says that with high blood pressure, the best prevention is knowing the blood pressure reading and making changes that matter in order to prevent and manage the condition.

Best CBD Oils For High Blood Pressure

A sublingual application of CBD oil tincture as the best way to take CBD for high blood pressure as it gets absorbed by the body fast and the effects are felt for an extended period. 

To get you started in your search, here are some of the top CBD oils for blood pressure on the market:

1. Spruce 2400mg Lab Grade CBD Oil

Spruce 2400mg Lab Grade CBD Oil Bottle

The largest bottle of CBD oil that Spruce offers contains 2,400mg of CBD. This is full-spectrum CBD oil, which is the maximum possible potency. Each high potency dropper full contains 80mg of CBD. There are no flavorings in it, which allows for the most CBD to fit in the 30ml bottle.

Check Latest Price
Read our review

2. cbdMD CBD Oil Tinctures

cbdMD CBD Oil Tinctures Products

cbdMD’s CBD oil tinctures are made using only CBD sourced from medical hemp and MCT oil as a carrier oil. Tinctures are offered in orange, mint, natural, and berry flavors. Safe for daily use, the oil tinctures are packaged with a built-in rubber dropper to adjust CBD dosage easily. The packaging is made to be easy to transport and discreet to use.

Check Latest Price
Read our review

3. Sunsoil CBD Oil Drops, Chocolate Mint Flavor

Sunsoil CBD Oil Drops, Chocolate Mint Flavor Bottle

CBD oil is not known for fantastic flavor, but with Sunsoil Chocolate Mint CBD oil you can appreciate all the health benefits without the unpleasant aftertaste. This product is made using the company’s coconut-derived MCT oil and features its full-spectrum premium CBD oil. This bottle contains 600 mg divided into 60 ml. The result is 60 servings, each with 10 mg of CBD. Sunsoil is proud that this product is full-spectrum, tastes great, features organically grown hemp, and has been third-party lab tested in ISO-accredited labs. It is available in just one size and concentration:

Check Latest Price
Read our review

Why People Are Taking CBD for High Blood Pressure

According to the Centers for Disease Control and Prevention (CDC), high blood pressure can harden the arteries, which decreases the flow of blood and oxygen to the heart, leading to heart disease.

In a study, CBD was shown to be a potent vascular relaxant to human arteries, suggesting its potential benefits to dilate blood vessels and increase blood flow.

How CBD Oil Works to Help with High Blood Pressure

Studies suggest that CBD may help lower blood pressure by addressing health issues that may cause blood pressure to rise.

  • CBD’s Anti-Anxiety Effects

Some factors linked to high blood pressure are anxiety and lack of sleep. 

In a study, sleep and anxiety scores were measured in human subjects, and the findings showed that CBD could hold benefits for anxiety-related disorders. 

In another study, CBD was shown to help in the treatment of post-traumatic stress disorder (PTSD).

The relaxation response can reduce blood pressure in people with hypertension, as indicated in the results of a study conducted by Harvard Medical School.

  • CBD as a Vasodilator

As a natural vasodilator, CBD can help improve positive cardiovascular health by widening the blood vessels to allow smooth blood flow.

CBD’s role as a vasodilator was highlighted in a double-blind, placebo-controlled, and randomized crossover study conducted in 2017 by the University of Nottingham.

In the study, researchers explored the connection between CBD and a reduction in blood pressure, and they found that a single dose of CBD oil significantly lowered blood pressure in human volunteers, both under stress and at rest.

 However, the authors also noted that “there are no dedicated studies in humans to date, to our knowledge, looking at the effect of CBD on either resting cardiovascular measurement or on the responses to stress, with continuous monitoring of cardiovascular parameters.”

  • CBD’s Anti-Inflammatory Effects

Studies also reveal that CBD possesses anti-inflammatory properties. Since inflammation can cause high blood pressure or vice versa, eliminating inflammation may help alleviate high blood pressure.

However, inflammation may be a symptom of other diseases as well. Thus, people are advised to continue leading a healthy lifestyle while using CBD oil.

  • CBD vs. Cortisol Secretion

Cortisol, the “stress hormone,” is released by the body under stress. An elevated cortisol level may cause a physical stress response in the body that could raise blood pressure. 

Results from a 1993 study suggest that CBD interferes with cortisol secretion. Thus, if high blood pressure is due to elevated stress levels, CBD oil may be beneficial.

  • CBD and The Dynamics of Blood Flow 

In a systematic review and meta-analysis that examined the hemodynamic (blood flow) effects of CBD, researchers concluded that CBD might be used as a potential remedy for cardiovascular disorders, such as hypertension and stroke. 

However, the authors of the study found no evidence that CBD provides similar results under non-stressful conditions. Data from human studies on the effects of CBD on hemodynamics is still limited.

  • CBD Interacts with Neurotransmitters

Cardiac contractility is a type of hypertension characterized by the heart pumping blood too fast, causing excessive cardiac activity.

Studies show how a neurotransmitter, such as anandamide, plays a critical role in the functioning of the heart. Results indicate that CBD oil regulates the reuptake of essential heart neurotransmitters that control the cardiovascular system.

  • CBD’s Neuroprotective Effects

Studies show how CBD allows blood flow in the vessels to maintain healthy blood pressure. The review has also presented evidence of the positive effects of CBD in the cardiovascular system.

Data from the studies illustrate that CBD potentially provides neuroprotective effects, which protects the heart against any cardiovascular conditions and stroke.

The findings also suggest that CBD can induce a healthy heart rhythm after an ischemic attack, which is caused by a build-up or blockage in the arteries. Thus, CBD was shown to improve heart performance immediately after a heart attack.

Although the results suggest that the cardiovascular system is a valid therapeutic target for CBD, the target sites of action for CBD remain to be established for most of the responses.

As more and more studies and clinical trials are conducted, CBD oil’s efficacy in treating high blood pressure would become more explicit.

The Pros and Cons of CBD Oil for High Blood Pressure

The Pros

  • CBD “is generally well tolerated with a good safety profile,” as  the World Health Organization (WHO) states in a critical review.
  • CBD’s efficacy as a potential remedy to hypertension-related symptoms has been shown in numerous studies.

The Cons

  • Studies are too limited to determine whether or not CBD is an effective treatment for conditions other than the ones approved by the U.S. Food and Drug Administration (FDA). 
  • As with the use of any natural chemical compound, there are risks involved in using CBD. Possible side effects include diarrhea, fatigue, and changes in appetite and weight.
  • Most of the results from blood pressure-related studies done on CBD have been gathered through tests that involve either healthy human volunteers or animals, like that of a study done on rats. Given the limited scope, facts cannot be established that the results of previous investigations would be comparable with that of tests involving ill human subjects.
  • CBD can alter how the body metabolizes certain medications. Thus, the combination of CBD with other high blood pressure medications is a big concern for someone who is planning to use CBD for hypertension.

Research indicates that the CYP450 family of enzymes is responsible for metabolizing several phytocannabinoids (cannabinoids that exist naturally in the cannabis plant), including CBD.

If one is already on high blood pressure medication, taking CBD in combination with the prescribed drug can lower blood pressure too much. Blood pressure that is too low is as bad as blood pressure that is too high.

Experts recommend that one speaks with a physician before adding CBD onto the medication that he or she is already taking. The doctor may want to reduce the dosage strength of the blood pressure prescription before incorporating CBD oil into the daily regimen of an individual. 

How CBD Oil Compares to Alternative Treatments for High Blood Pressure

Although the prescription medications currently available for hypertension are effective, they bring about side effects, which can make the treatment an unpleasant experience. 

Cannabidiol (CBD), on the other hand, is a natural alternative that has shown to have little side effects, and the side effects of CBD are less common than the effects associated with most pharmaceutical medications used to treat high blood pressure.

How To Choose The Right CBD for High Blood Pressure

The best CBD oil product to use for high blood pressure is CBD tincture. By taking a sublingual dosage, one gets the optimum level of CBD absorbed, which means CBD works the fastest, and the effects are probably felt the longest. 

However, regardless of the form of CBD product one chooses, he or she must employ careful consideration in choosing the best CBD oil for high blood pressure that is right for him or her.

The following factors are essential to ensure the safety and reliability of the CBD products purchased:

  1. Research on the exact legal stipulations applicable to CBD in the area where it would be purchased and used.
  2. Purchase only from legitimate and reliable big brands. Majority of companies that manufacture the best CBD oil products purchase their hemp from farms that are located in California, Texas, Europe, and Colorado.
  3. When buying from an online store, research product reviews. When buying from a physical store or dispensary, check whether the store is authorized by the government to sell CBD.
  4. One important thing to look for in CBD products is certification codes. Several certification authorities approve certain products only after some thorough screening tests. 
  5. Compare company claims about their products’ potency with that of the third-party lab reports. 
  6. Consulting with a trusted medical professional who is experienced in CBD use is ideal before one purchases his or her first bottle of CBD. 

Best CBD Oils For High Blood Pressure 

1. Spruce 2400mg Lab Grade CBD Oil

Spruce 2400mg Lab Grade CBD Oil Bottle

The largest bottle of CBD oil that Spruce offers contains 2,400mg of CBD. This is full-spectrum CBD oil, which is the maximum possible potency. Each high potency dropper full contains 80mg of CBD. There are no flavorings in it, which allows for the most CBD to fit in the 30ml bottle.

Check Latest Price
Read our review

2. cbdMD CBD Oil Tinctures

cbdMD CBD Oil Tinctures Products

cbdMD’s CBD oil tinctures are made using only CBD sourced from medical hemp and MCT oil as a carrier oil. Tinctures are offered in orange, mint, natural, and berry flavors. Safe for daily use, the oil tinctures are packaged with a built-in rubber dropper to adjust CBD dosage easily. The packaging is made to be easy to transport and discreet to use.

Check Latest Price
Read our review

3. Sunsoil CBD Oil Drops, Chocolate Mint Flavor

Sunsoil CBD Oil Drops, Chocolate Mint Flavor Bottle

CBD oil is not known for fantastic flavor, but with Sunsoil Chocolate Mint CBD oil you can appreciate all the health benefits without the unpleasant aftertaste. This product is made using the company’s coconut-derived MCT oil and features its full-spectrum premium CBD oil. This bottle contains 600 mg divided into 60 ml. The result is 60 servings, each with 10 mg of CBD. Sunsoil is proud that this product is full-spectrum, tastes great, features organically grown hemp, and has been third-party lab tested in ISO-accredited labs. It is available in just one size and concentration:

Check Latest Price
Read our review

CBD Dosage For High Blood Pressure

Read the dosing instructions on the CBD product of choice and start with a low dose. Taking high doses at the beginning may bring about adverse reactions in the user. 

As with any medication, the dose would depend on the metabolism, genetics, size, and body weight of a person.

In a review, Mayo Clinic suggests CBD dosages based on publications, scientific research, traditional use, and expert opinion. The doses and duration of treatment depend primarily on the illness. 

However, there is no specific dose recommended for high blood pressure. 

Results of a study provided evidence that CBD dosage of up to 1,500 mg a day is well-tolerated by humans. 

The authors of the study also found that at lower doses, CBD showed physiological effects that could potentially help promote and maintain health, including antioxidative, anti-inflammatory, and neuroprotection effects.

How to Take CBD Oil for High Blood Pressure 

There are various ways to consume CBD oil, and the delivery format would most likely depend on personal preferences and lifestyle.

CBD Oil Capsules and Edibles

CBD oil capsules and edibles, such as brownies, gummies, and lozenges, are a convenient and straightforward way to take CBD oil, especially for beginners.

This format is easy to work into a routine, and the dose is consistent. Depending on the metabolism of an individual, the effects can last between 6 and 12 hours. Thus, one dose is probably all that is needed during the day.

However, eating CBD oil can delay its effects as it has to pass through the digestive system before it gets absorbed into the bloodstream. Given that the effects of the CBD oil could take at least 20 minutes to an hour to appear, CBD oil capsules and edibles do not provide immediate relief.

CBD Oil Tinctures or Drops

CBD oil tinctures or drops are a practical option for those who seek fast results and maximum dosage control.

Tinctures and drops are administered under the tongue, through which the CBD oil is absorbed directly into the bloodstream. 

Place the desired quantity of drops under the tongue using a dropper, and then let the CBD oil stay in place for at least 60 seconds. Once 60 seconds have passed, swallow the CBD oil.

Sublingual application allows for results to be experienced within 30 to 60 minutes after its use, and the effects can be felt for 4 to 6 hours.

Since tinctures and drops are convenient and easy to store and travel with, they can be effortlessly administered when needed.

However, one significant drawback to CBD oil tinctures and drops is the taste as not everyone appreciates the natural, earthy, and sometimes bitter flavor of hemp.

Although some products come in various flavors to compensate for the unpleasant taste, the addition of sugar and chemicals may be something that one wants to avoid.

CBD Oil Vapes

CBD oil vapes are one of the accelerated ways to get CBD into the body since it enters the bloodstream through the lungs, without going through the digestive system. 

When vaping CBD oil, effects can be felt in minutes. However, the effects last only for 30 minutes to an hour or two.

Also, with vaping, it is difficult to determine precisely how much CBD is in each draw. Although labels for CBD oil vape products usually indicate the amount per inhale, the amount may vary in individuals. Thus, getting the dose right requires a bit of experimentation at first. 

Understanding High Blood Pressure

Blood pressure is influenced by how much blood the heart pumps and the resistance to blood flow in the arteries. The higher the amount of blood the heart pumps and the narrower the arteries, the higher the blood pressure.

The narrowing and blocking of blood vessels that is caused by high blood pressure, or hypertension, affects heart health by increasing the risk of developing heart failure.

What A Blood Pressure Reading Means

When a doctor measures blood pressure, the reading is given in two numbers. The first number, referred to as systolic blood pressure, is the pressure caused by the heart contracting and releasing blood. The second number, called diastolic blood pressure, is the pressure when the heart relaxes and fills with blood. 

The blood pressure reading is given as the systolic blood pressure number over the diastolic blood pressure number, such as 135/70. A normal blood pressure reading for adults is 120/80.

Are There High Blood Pressure Symptoms?

The American Heart Association (AHA) calls high blood pressure a “silent killer.” An individual can have high blood pressure for years without any indications. 

Most people with high blood pressure do not exhibit symptoms, even though blood pressure readings rise to critically-high levels.

Meanwhile, some people with high blood pressure may experience shortness of breath, headaches, or nosebleeds. However, these symptoms are not specific and do not occur until high blood pressure has reached a life-threatening stage.

Still, even in the absence of symptoms, damage to the heart and blood vessels continues and can be detected. 

Unregulated high blood pressure intensifies the risk of severe health problems, including strokes and heart attacks.

High blood pressure typically develops over several years, and it eventually affects almost everyone. The National Institute on Aging (NIA) states that high blood pressure is  a critical health issue that is typical among old people.

Fortunately, it is not difficult to detect high blood pressure. One can work with a doctor to control the condition once diagnosed.

To learn more about the studies on blood pressure, go to or

Traditional Medications for High Blood Pressure

Doctors often prescribe the following pharmaceutical drugs to people dealing with high blood pressure:

  • Diuretics, like Diuril and Lozol, increase urination which reduces sodium and fluid in the body. Because diuretics lower blood volume, they help lower blood pressure. However, one side effect of diuretics is a loss of potassium, which is needed for proper muscular movement. 
  • Angiotensin II receptor blockers (ARBs) like Diovan, which, as vasodilators, dilate blood vessels. Their potential side effects include skin rashes, joint and back pain, flu-like symptoms, nausea, headaches, and diarrhea.
  • Metoprolol beta-blockers, like Toprol-XL and Lopressor, slow the heart rate. However, they can cause diarrhea, constipation, vomiting, fatigue, anxiety, depression, insomnia, shortness of breath, and decreased libido.
  • Angiotensin-converting enzyme (ACE) inhibitors like Vasoctec and Benazepril prevent the contraction of blood vessels. Some adverse side effects may include skin rash, dry cough, headaches, dizziness, and diarrhea.

The blood pressure medications currently available in the market may induce damaging effects on the body. Organs that are typically affected are the kidneys, which have to filter the compounds left over by the medicines. 

Usually, a combination of two or more anti-hypertensive drugs is required in order to control hypertension. 

However, mixing beta-blockers and angiotensin II receptor antagonists must only be done at the recommendation of a physician since the combination can lead to acute renal failure, as one study suggests.

Lifestyle Changes to Help Prevent High Blood Pressure

Using medications as prescribed and making lifestyle changes can enhance the quality of life and reduce the risk of hypertension, says the American Heart Association (AHA). These changes include:

  • Eating a healthy diet that is low in fat, cholesterol, and salt to prevent further plaque build-up in the arteries.
  • Exercising regularly to strengthen your heart. This activity could be something as simple as taking a 30-minute walk each day.
  • Engaging in activities that help manage stress, such as meditation, journaling, making art, and seeing a therapist.

What to Know About CBD Oil

CBD oil contains CBD, or cannabidiol, as its primary active ingredient. Cannabidiol is associated with the previously mentioned benefits, including controlling blood pressure.

Comparing CBD and THC

CBD comes from cannabis and is naturally found in hemp plants. CBD is one of more than 100 cannabinoids that occur naturally within the plant. This compound is also commonly used to produce CBD hemp oil supplements. 

Hemp seed oil is produced by extracting the oil from the seeds of the hemp plant itself. This oil is abundant in nutrients, such as omega-3 and omega-6 fatty acids, making it ideal for digestion. Although some people refer to “hemp extract” as hemp oil, the term “hemp oil” is synonymous with the term “hemp seed oil.”

Chemical compounds in cannabis, called cannabinoids, have shown various potential benefits by activating the body’s endocannabinoid system (ECS), which is involved in regulating a variety of functions including sleep, appetite, pain and immune system response

The body produces endocannabinoids, which are neurotransmitters that bind to cannabinoid receptors in the nervous system.

The medicinal efficacy of cannabis can be optimized by incorporating the various cannabinoids, flavonoids, and terpenes that are intrinsic components of cannabis plants.

CBD is non-psychoactive, contrasting with THC (tetrahydrocannabinol), another primary cannabinoid. THC is the most significant factor contributing to the high associated with using cannabis. 

Consuming CBD without any THC does not produce those effects, which means that nearly everyone should be able to function as they usually do when taking CBD. 

The lack of high lets one continue with work, school, and other commitments without a decrease in performance. It also makes CBD oil safe to take, even for those who must pass regular or random drug tests.

CBD oil must not contain any THC for CBD to be non-psychoactive. Products containing CBD isolates do not have THC, while full spectrum CBD products do. 

Any product that one buys should also state the percentage of THC, information which one can also get from its certificate of analysis.

Other Health Benefits of CBD Oil

Here are some of the more critical benefits associated with cannabidiol.

  • Treating Seizures

CBD can help treat some of the worst types of seizure disorders that exist, including Lennox-Gastaut syndrome and Dravet syndrome, both of which affect children and do not typically respond to traditional medications for treating seizures.

Even the U.S. Food and Drug Administration (FDA) recognizes the ability of CBD to treat seizure disorders. The first cannabis-derived medication it approved is Epidiolex, which treats these conditions. That medication contains CBD.

  • Treating Anxiety Disorders and Depression 

Those who suffer from anxiety experience relief with CBD. One study showed this effect on public speaking, and there is plenty of anecdotal evidence.

Results from a study indicate that CBD attenuates oxidative stress, as well as cardiac dysfunction, fibrosis, and cell death.

  • Treating Pain

One of the most popular uses of CBD oil is its ability to reduce chronic pain. Animal studies, including one in the European Journal of Pain, show that topically applied CBD can provide pain relief and reduce inflammation from arthritis. 

Other studies show that CBD can reduce neuropathic and inflammatory pain. This finding is crucial as those are two of the hardest types of pain to treat.

Some countries approve oral sprays like Sativex, which contains both CBD and THC. This spray effectively treats the pain associated with multiple sclerosis (MS). Multiple sclerosis is a potentially disabling disease of the brain and spinal cord (central nervous system). 

However, as Sativex and certain medications may trigger a drug interaction, experts advise that one talks to a doctor first about all the prescription, over-the-counter (non-prescription), and herbal medications that he or she is taking before starting to use Sativex oral spray.

  • Protecting the Brain

CBD research in animal models and humans has shown numerous therapeutic properties for brain function and protection, both by its effect on the endocannabinoid system directly and by influencing endogenous cannabinoids.

Researchers in a study noted a possible effect of CBD in improving the quality of life in patients with Parkinson’s disease without adverse outcomes.

Studies analyzed in a review also provided proof of principle for the therapeutic benefits that CBD and possibly CBD-THC combinations provide for the therapy of Alzheimer’s disease (named after Dr. Alois Alzheimer who noted the symptoms in 1906).

  • May Help Fight Cancer

Several studies showed a CBD-induced cell death of breast cancer cells, suggesting that the use of CBD oil may also suppress tumor growth.

Research demonstrates that cannabinoids can also prove beneficial in certain types of cancers that are activated by chronic inflammation. In such instances, cannabinoids, as anti-inflammatory agents, can either directly prevent tumor growth or suppress inflammation.

Meanwhile, in-depth research on CBD yields mixed results. 

In a study, researchers recognized the antitumor effects of cannabinoids in various cancer types.

However, these antitumor effects of cannabinoids have to prevail over their known immunosuppressive effects, which can potentially promote the production or formation of tumors.

Recent studies are still limited when it comes to CBD and cancer prevention. Longitudinal studies of humans using specific CBD products, controlling for frequency of use and dosing are needed.

  • Overcoming Substance Abuse

There is some evidence that using CBD can help those with addiction overcome their substance abuse. 

A study conducted on animal models showed CBD reduced heroin-seeking behavior and reduced morphine dependence.

The Legality of CBD Oil

The Cannabis sativa plant produces both hemp and marijuana. The difference between the two plants is the percentage of THC that they contain. 

A cannabis plant that has 0.3 percent or less of THC content classifies as hemp, while a cannabis plant containing over 0.3 percent of THC is considered marijuana.

In the United States, cannabis-related laws are continually changing. Since marijuana and THC are on the list of controlled substances, they are currently prohibited under federal law.

Meanwhile, confusion arises due to regulations that vary depending on whether the CBD is hemp-derived or extracted from marijuana. The former is legal at the federal level, while the latter is not. 

Many states and Washington, D.C. have passed cannabis-related laws, making medical marijuana with high levels of THC legal. Still, marijuana may require a prescription from a licensed physician.

Also, several states have made recreational use of marijuana and THC legal. One should be able to buy CBD in states where marijuana is legal for recreational or medical purposes.

To get more information on state laws and penalties, click here

If one possesses cannabis-related products in a state where they are illegal or if one does not have a medical prescription in states where the products are legal for medical treatment, he or she could face legal penalties.

For a complete list of legal medical marijuana states and D.C., including the corresponding laws, fees, and possession limits, click here.


According to the Centers for Disease Control and Prevention (CDC), about 75 million American adults, or 1 in 3 adults, have high blood pressure. People with high blood pressure have a greater risk of heart disease and stroke, the leading causes of death in the United States.

CBD oil has shown to be a natural remedy to issues that could be linked to high blood pressure, such as stress and pain

Meanwhile, using medications as prescribed and making lifestyle changes can enhance the quality of life and reduce the risk of hypertension, says the American Heart Association (AHA).

Still, before experimenting with different CBD products and dosages, speak to a doctor about a CBD treatment or using CBD oil for treating high blood pressure.

For anyone still looking for more information on CBD as a medical supplement, speaking with a cannabis doctor who specializes in the subject is the best course of action.

There is a wide range of products to choose from for those who are ready to decide which product and how they would like to take CBD oil to either address medical conditions or maintain general well-being.

Clarence Swader

Latest posts by Clarence Swader (see all)

Toxic and Non-Toxic Causes of High Blood Pressure

High blood pressure or hypertension is a condition characterized by elevated blood pressure. Although this is frequently defined as a systolic blood pressure greater than 160 mmHg and diastolic blood pressure greater than 95 mmHg, such absolute figures must be interpreted in terms of age and ethnicity.

Toxic Causes of High Blood Pressure Specifics
Corticosteroids Androgens
Mineralocorticoids (including black liquorice)
Disulfram/ethanol interaction
Envenomations Scorpions and spiders (Lactrodectus species, Atrax species)
Human Recombinant Erythropoeitin
Metals Barium, Cadmium, Lead, Lithium, Mercury, Sodium, Thallium
Natural toxins ephedra alkaloids
Non-steroidal anti-inflammatory drugs
Selective serotonin-reuptake inhibitors
Sympathomimetics (includes pure alpha adrenoreceptor agonists) Amphetamines, Caffeine, Clonidine (early stages), Cocaine, Ephedrine, Epinephrine, Ergotamines, Levodopa, Metaraminol, Methoxamine, Monamine Oxidase Inhibitors, Norepinephrine, Oxymetazoline, Phencyclidine, Phenylephrine, Phenylpropanolamine, Pseudoephedrine, Tetrahydralozine
Withdrawal states
Coarctation of the aorta
Essential (idiopathic) hypertension
Hyperadrenergic states Agitation, exercise
Hypertensive disease of pregnancy
Raised intracranial pressure
Renal parenchymal hypertension
Renovascular hypertension


Treatment and Monitoring of Hypertension

Hypertension associated with chronic intoxications is usually mild and resolves with identification and removal of the offending agent. In the case of metal intoxications, specific therapy in the form of chelation may be indicated. Hypertension associated with the majority of acute intoxications is mild and requires no more than simple observation until it resolves.

Hypertension following acute overdose is usually of short duration (hours) and parallels the duration of other clinical features of the intoxication. The blood pressure should be frequently measured, especially during the early phases of the intoxication. In severe cases, especially where parenteral hypotensive agents are in use, continuous monitoring via an arterial line is ideal. Very frequent non-invasive blood pressure measurements are an alternative where such facilities are unavailable.

During the hypertensive period, the patient should be closely observed for evidence of the principal acute complications; aortic dissection, intracranial hemorrhage, left ventricular failure and myocardial infarction. Long-term complications from hypertension of toxic aetiology are rare but may include those resulting from intracranial hemorrhage, acute myocardial infarction and retinal hemorrhage.

Fatoumah Alabdulrazzaq, MD and Gideon Koren, MD, FRCPC, FACMT

July 2012



Many of my pregnant or lactating patients are taking calcium channel blockers (CCBs) for hypertension. How safe is maternal use of CCBs for fetuses and nursing infants?


Generally, CCBs have not been shown to increase teratogenic risk. Information regarding the safety of CCBs during lactation is limited, although they are not likely to pose a risk to the nursing infant.


Bon nombre de mes patientes enceintes ou qui allaitent prennent des inhibiteurs calciques (IC) pour l’hypertension. Dans quelle mesure l’utilisation maternelle des IC est-elle sécuritaire pour le fœtus et les nourrissons allaités?


En règle générale, il n’a pas été démontré que les IC présentaient un risque tératogène. Les renseignements concernant l’innocuité des IC durant l’allaitement sont limités, mais il est improbable qu’ils posent un risque pour le nourrisson allaité.

Calcium channel blockers (CCBs) are commonly used during pregnancy and lactation to treat hypertension, arrhythmia, and preeclampsia. They have also been used as tocolytic agents to prevent premature labour and its complications.

Population-based data from 5 health maintenance organizations in the United States were used to study the risks of perinatal complications and congenital defects among infants exposed in utero to CCBs or ß-blockers. Calcium channel blocker use in the third trimester was associated with increased risk of neonatal seizures, jaundice, and hematologic disorders (relative risk [RR] 3.6, 95% CI 1.3 to 10.4). The risk of neonatal convulsions was in part attributed to the placental transfer of CCBs, leading to a decrease in infants’ cellular calcium levels.1 There was no increase in risk of congenital anomalies in either group of infants. The risk of one or more malformations was not elevated in the group of infants exposed to CCBs (RR 0.96, 95% CI 0.47 to 1.97). 1

The Motherisk program reported no increased teratogenic risk of perinatal complications among 78 women exposed to CCBs in the first trimester. Maternal hypertension was the most important factor responsible for babies with low birth weights in this group. 2

The Swedish Medical Birth Register studied a cohort of 1418 pregnancies in which the mothers took anti-hypertensive drugs in early pregnancy; in 217 pregnancies, the mothers took CCBs. Three babies were born with congenital heart defects (RR 1.15). The study concluded that there was little drug specificity in the association between maternal use of antihypertensive drugs and increased risk of infant cardiovascular defects. 3

A Hungarian case-control study identified 22 865 infants with congenital abnormalities and 31 151 healthy population control babies between 1980 and 1996; 586 mothers had been exposed to CCBs during pregnancy compared with 907 mothers in the control group. The overall prevalence ratios for 17 congenital abnormalities varied between 1.1 and 1.4, and there was no significant increase in risk of congenital abnormalities. 4

All CCBs pass into the breast milk in small amounts. 5-7 Both LactMed (Drugs and Lactation Database) and the American Academy of Pediatrics conclude that this class of medications is compatible with breastfeeding. 8 It is advisable to follow up with any exposed infant for signs of hypotension.

Calcium channel blockers can be safely used during pregnancy and breastfeeding.

CAS # 92-52-4 C12H10 / C6H5C6H5
RTECS # DU8050000 Molecular mass: 154.2
UN # 3077

EC # 601-042-00-8

Physical properties:

Boiling point: 256°C
Melting point: 70°C
Relative density (water = 1): 1.04
Solubility in water: none
Vapour pressure, Pa at 71°C: 133
Relative vapour density (air = 1): 5.3
Relative density of the vapour/air-mixture at 20°C (air = 1): 1.0
Flash point: 113°C c.c
Auto-ignition temperature: 540°C
Explosive limits, vol% in air: 0.6 (at 111°C) – 5.8 (at 166°C)
Octanol/water partition coefficient as log Pow: 3.16/4.09

Biphenyl is combustible. No open flames should be in close proximity. Finely dispersed particles form explosive mixtures in air. Prevent deposition of dust; closed system, dust explosion-proof electrical equipment and lighting. Prevent build-up of electrostatic charges (e.g., by grounding).

Biphenyl can be absorbed into the body by inhalation and by ingestion. Prevent dispersion of dust. Avoid inhalation of fine dust and mist. Use local exhaust or breathing protection.

Protect the skin. Wear protective gloves. Remove contaminated clothes. Rinse and then wash skin with water and soap. Do not take working clothes home.

Biphenyl may cause redness and pain in the eyes. Prevention include safety goggles or eye protection in combination with breathing protection if powder. In case of contamination, first rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.

For spillage disposal, sweep spilled substance into sealable containers; if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to a safe place. Personal protection: A/P2 filter respirator for organic vapour and harmful dust. Do not let this chemical enter the environment.

For safety storage, keep separated from food and feedstuffs, oxidants. For packaging and labelling, do not transport with food and feedstuffs.

Biphenyl can be absorbed into the body by inhalation and by ingestion. Physical dangers of Biphenyl include dust explosion possible if in powder or granular form, mixed with air. A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20°C. Chemical dangers of Biphenyl include how it reacts with oxidants. Effects of short-term exposure: The substance is irritating to the eyes and the respiratory tract. Effects of long-term exposure: The substance may have effects on the liver and nervous system, resulting in impaired functions.

Biphenyl may be hazardous to the environment; special attention should be given to water quality. Bioaccumulation of this chemical may occur along the food chain, for example in plants. It is strongly advised not to let the chemical enter into the environment because it persists in the environment.


Taking angiotensin-converting enzyme inhibitors during pregnancy – Is it safe?

Almundher Al-Maawali, MD, Asnat Walfisch, MD and Gideon Koren, MD, FRCPC, FACMT

January 2012



One of my 35-year-old pregnant patients has been treated with enalapril for primary hypertension. She learned she was pregnant at 11 weeks’ gestation. I read somewhere that angiotensin-converting enzyme (ACE) inhibitors can cause malformations. What advice do you give to Motherisk callers?


Most published studies have failed to show an effect of ACE inhibitors on congenital malformations. A recent systematic review and meta-analysis conducted by Motherisk does not suggest increased fetal risk of malformations. However, ACE inhibitors should be avoided in late pregnancy, as they might cause renal failure and acalvaria in the baby.


L’une de mes patientes enceintes âgée de 35 ans est traitée avec de l’énalapril pour une hypertension primaire. Elle a appris qu’elle était enceinte après 11 semaines de gestation. J’ai lu quelque part que les inhibiteurs de l’enzyme de conversion de l’angiotensine (ECA) peuvent causer des malformations. Quels conseils donnezvous à ceux qui posent des questions à ce sujet à Motherisk?

La plupart des études publiées n’ont pas réussi à révéler des effets attribuables aux inhibiteurs de l’ECA sur les malformations congénitales. Une récente synthèse critique et une méta-analyse réalisées par Motherisk n’indiquent pas qu’il puisse y avoir des risques fœtaux accrus de malformations. Toutefois, il faudrait éviter les inhibiteurs de l’ECA en fin de grossesse, car ils pourraient causer une insuffisance rénale et l’absence de voûte crânienne chez le bébé.


Essential hypertension is a common diagnosis among young women.1 Depending on the population studied, the incidence during pregnancy ranges from 0.5% to 3.0%.2 Different types of hypertensive disorders during pregnancy include chronic hypertension, gestational hypertension, and preeclampsia, accounting for most antenatal care provision.3 Risks to the mother include maternal death, stroke, heart failure, and pulmonary edema. The fetus is also at risk, and common fetal complications include intrauterine growth restriction, placental abruption, and prematurity.4

Angiotensin-converting enzyme (ACE) inhibitors are widely used as first-line therapy for chronic hypertension. They are frequently used in women of reproductive age; consequently, some women are bound to be taking ACE inhibitors at the time of conception, as more than half of all pregnancies are unplanned.4

Captopril, enalapril, and lisinopril cross the human placenta in pharmacologically significant amounts. It is conceivable that other ACE inhibitors have similar placental transfer.5,6

Animal studies

While the results of animal studies on the use of ACE inhibitors during pregnancy vary, most of them have failed to show increased malformation rates. However, animal data reveal increased morbidity and mortality in fetuses exposed to ACE inhibitors in utero. A prospective placebo-controlled study of baboons showed a significant increase in fetal death or fetal growth restriction (4 of 13) in the group treated with enalapril when compared with placebo (P < .05).7 Use of captopril in maternal sheep during late pregnancy caused low fetal blood pressure, and the risk of stillbirth was substantially elevated.8

First-trimester human exposure

Cooper and colleagues9 reported an increased risk of congenital malformations in fetuses exposed to ACE inhibitors during the first trimester. They studied a cohort of 29 507 infants who were enrolled in Tennessee Medicaid, who were born between 1985 and 2000, and for whom there was no evidence of maternal diabetes. Out of this cohort, 209 infants with exposure to ACE inhibitors in the first trimester were identified. The risk ratio for major congenital malformations was 2.71 (95% 1.72 to 4.27). It has been argued that these findings were affected by confounding and ascertainment biases. These include the inability to exclude women with undiagnosed or diet-controlled type 2 diabetes mellitus, no adjustment for prepregnancy body mass, which is a considerable predictor of risk of type 2 diabetes mellitus, and uncontrolled hypertension.10 In infants, maternal obesity is an independent risk factor for neural tube defects and cardiac malformations.11,12

Recently, Motherisk13 conducted a systematic review of the literature and meta-analysis evaluating the use of ACE inhibitors during the first trimester of pregnancy and their association with major congenital malformations. We identified 5 cohort studies for the meta-analysis and included 19 case reports, case series, or case-control studies in the descriptive part of the systematic review. The meta-analysis failed to demonstrate an increase in major malformations after use of ACE inhibitors or angiotensin II receptor blockers (ARBs) specifically, with no difference from exposure compared with other antihypertensive medications. The systematic review of the case reports and case series published in the past 25 years involved 424 pregnancies. These reports do not suggest a specific pattern of malformations.

Diav-Citrin et al recently studied 252 pregnancies exposed to ACE inhibitors and ARBs, 256 pregnancies exposed to other antihypertensive medications, and 495 control pregnancies from 2 teratology information services in Israel and Italy. They concluded that ACE inhibitors and ARBs are not major teratogens when used in the first trimester, and the risk of major congenital malformations was comparable between the groups (P = .95). In this study, women with known diabetes (both preexisting and gestational) were not excluded, and there was no adjustment for maternal body mass index.14

Serreau et al reported on 10 cases of pregnant women exposed to ARBs during early pregnancy. One out of the 8 fetuses exposed exclusively during the first trimester was reported to have craniofacial dysmorphia, clinodactyly, and tubular dysplasia.15

In a cohort retrospective review of 348 989 infants or fetuses from all pregnancies in Finland (N = 343 324), exposure of infants or fetuses to ACE inhibitors (n = 137) was associated with an increased risk of major congenital malformations, mostly cardiac. However, when adjusted for diabetes, the excess risk was nullified.16

Lennestål et al17 reported on a cohort of 1418 women from the Swedish Medical Birth Register who had used antihypertensive drugs in early pregnancy but who did not have diabetes. Cardiovascular defects occurred with an adjusted odds ratio of 2.59 (95% CI 1.92 to 3.51). However, the results were similar when the women had used ACE inhibitors or other antihypertensive drugs, without any clear drug specificity.

In France, data on 159 pregnancies with exposure to ACE inhibitors and 159 controls were obtained. Pregnancies with confirmed first-trimester exposure to ACE inhibitors were included. The rate of major malformations in live births or stillbirth was not different between the 2 groups (relative risk 1.5, 95% CI 0.3 to 6.5).18

Second and third trimesters

Second- and third-trimester exposure to ACE inhibitors is associated with oligohydramnios, hypocalvaria, anuria, renal failure, neonatal hypotension, and patent ductus arteriosus.1921 It is also associated with aortic arch obstructive malformations.22 Some of these infants exhibit severely impaired renal function and hypoplastic lungs owing to oligohydramnios, and they might progress to death or end-stage renal failure. The cause of these defects appears to be related to inhibitory effects on the renin-angiotensin-aldosterone system.23 The morbidity is estimated to be quite high; it is between 10% and 20% of infants exposed.4



Taking ACE inhibitors during pregnancy:Is it safe?

Savithiri Ratnapalan, MB BS, MRCP Gideon Koren, MD, FRCPC

June, 2002



A pregnant patient is taking enalapril for primary hypertension. How safe are angiotensin-converting enzyme inhibitors (ACEI) during pregnancy?


Evidence of whether ACEIs cause problems during the first trimester of pregnancy is reassuring. There is evidence that they cause severe renal and other problems during the second and third trimesters, however. These drugs should be avoided during pregnancy.


Une patiente enceinte prend de l’énalapril pour une hypertension primaire. Les inhibiteurs de l’enzyme de conversion de l’angiotensine (IECA) sont-ils sans risque durant la grossesse?


Les données probantes à savoir si les IECA causent des problèmes durant le premier trimestre de la grossesse sont rassurantes. Par ailleurs, il est démontré qu’ils causent de graves problèmes néphrologiques et d’autres problèmes durant le deuxième et le troisième trimestres. Ces médicaments devraient être évités durant la grossesse.


Incidence of chronic hypertension during pregnancy ranges from 0.5% to 3.0% depending on the population studied.1 Maternal and perinatal morbidity and mortality are generally not increased when patients have uncomplicated mild chronic hypertension. Risks to both mother and fetus increase dramatically, however, when pregnancy is complicated by severe uncontrolled hypertension or other risk factors, such as older maternal age, hypertension lasting more than 15 years, diabetes, renal disease, cardiac disease, or connective tissue disease.1 Some reported complications of uncontrolled hypertension during pregnancy are maternal death, stroke, heart failure, and pulmonary edema; common fetal complications are intrauterine growth restriction, abruption of the placenta, and prematurity and its adverse effects.1

Angiotensin-converting enzyme inhibitors are excellent antihypertensive agents with few side effects (Table 1). They are becoming widely used as first-line therapy for chronic hypertension in women of reproductive age. They are also used in treatment of renovascular hypertension, autoimmune diseases, and diabetes mellitus in this age group. Because 50% of all pregnancies are unplanned, some women are bound to be taking ACEIs at the time of conception.

Animal studies
Animal studies of rats and rabbits given ACEIs during organogenesis showed no increased incidence of major malformations in offspring. Animal data reveal, however, increased morbidity and mortality in fetuses exposed to ACEIs in utero. Decreased uteroplacental blood flow, low birth weight, hypotension, preterm delivery, and fetal death were noted.2 A prospective placebo-controlled study of baboons showed a significant increase in fetal death or fetal growth restriction (four of 13) in the group treated with enalapril compared with no instances among the controls.3

Placental transfer
Captopril, enalapril, and lisinopril have been shown to cross the human placenta in pharmacologically significant amounts; other ACEIs probably do the same.4-6 Once in a fetus, most ACEIs are excreted renally in their active form (when there is urine production) and could be recirculated through swallowed amniotic fluid.




Taking ACE inhibitors during early pregnancy

Joel G. Ray, MD MSc FRCPC, Marian J. Vermeulen, MHSc and Gideon Koren, MD FRCPC

September 2007



I knew that angiotensin-converting enzyme (ACE) inhibitors were risky to use during late pregnancy because they can cause renal shutdown in the fetus. Recently I heard of a study that claimed first-trimester exposure (when many patients still are unaware of their pregnancies) can also cause major malformations. Is this proven?


A recent study did suggest an increased risk of malformations after first-trimester exposure to ACE inhibitors among women treated for hypertension. We believe this study had serious limitations that preclude drawing any conclusions at present.


It is well accepted that angiotensin-converting enzyme (ACE) inhibitors are contraindicated during the second and third trimesters of pregnancy because of increased risk of fetal renal damage. First-trimester use, however, has not been linked to adverse fetal outcomes.

Cooper and colleagues conducted a study to assess the association between exposure to ACE inhibitors during the first trimester of pregnancy and risk of congenital malformations. 1 They followed a cohort of 29 507 infants from Tennessee Medicaid files who were born between 1985 and 2000 and whose mothers had no evidence of having had diabetes. The researchers identified 209 infants who had been exposed to ACE inhibitors during the first trimester only, 202 infants who had been exposed to other antihypertensive medications during the first trimester only, and 29 096 infants who had not been exposed to antihypertensive drugs. Infants who had been exposed to ACE inhibitors had a greater risk of major congenital malformations (risk ratio 2.71, 95% confidence interval [CI] 1.72 to 4.27) than did infants not exposed to antihypertensive medications. Being exposed to other antihypertensive medications did not result in an increased risk of major malformations (risk ratio 0.66, 95% CI 0.25 to 1.75). Infants exposed to ACE inhibitors were at increased risk of malformations of the cardiovascular system (risk ratio 3.72, 95% CI 1.89 to 7.30) and the central nervous system (risk ratio 4.39, 95% CI 1.37 to 14.02). The authors concluded that exposure to ACE inhibitors during the first trimester cannot be considered safe and should be avoided.

Leave a Comment