Marijuana Interactions With Medications May Put Heart Patients At Risk: Study

Using marijuana while taking certain medications may result in serious side effects, especially for individuals with heart conditions, according to new research.

In findings published as part of a review in the Journal of the America College of Cardiology on January 20, researchers indicate that the effectiveness and potency of certain medications for cardiovascular disease may be increased or decreased when combined with marijuana.

Research with Brigham and Women’s Hospital and Harvard Medical School used National Survey Data to estimate that 2 million U.S. adults with cardiovascular disease have reported using marijuana. These patients have various heart conditions, but are using a drug that can interfere with other medications they may be taking for their heart condition, including statins and blood thinners.

Observational studies have shown a link between marijuana and cardiovascular risks, but questions remain about the drug’s impact on the heart. Some worry smoking marijuana can pose some of the same cardiovascular health effects as smoking tobacco.

In recent years, several states have moved to legalize or decriminalize marijuana, and it’s use has become more widespread. In addition, certain strains have become more potent, which may further increase the risk.

Using marijuana while on a statin or blood thinners can change how the drugs work in the body. For example, the liver enzymes that break down statins or blood thinners also break down the compounds in marijuana. This means using marijuana with blood thinners or statins could change the effectiveness and potency of the drugs.

When taking blood thinners, marijuana use may increase the levels of medication in the body, since the liver is trying to process both the marijuana and the drug at the same time. As a result, this could lead to excessive bleeding. Researchers indicate that individuals using marijuana while on warfarin or similar blood thinners may need to reduce their dosage by as much as 30%.

Marijuana can also boost the potency of statins, such as Lipitor, which can cause dangerous drops in blood pressure. Additionally, marijuana can also cause platelets in the blood to clump and form clots, increasing the risk of stroke or heart attack.

Researchers warn that it is imperative that individuals on heart medications discuss their marijuana use with their doctor and pharmacist, so medications or dosages may be adjusted if necessary.

Individuals who have had a heart attack or were hospitalized for heart problems may face the highest risk, according to the findings. They should consider not using marijuana at all, or at least limiting it, the researchers noted.

For those who do not have a known heart condition, but use marijuana, researchers indicate that they should pay attention to their heartbeat. Heart palpitations are a common side effect of marijuana, and could be dangerous for individuals with an existing condition, especially if that condition is not diagnosed or being treated.

Because marijuana is classified as a schedule I substance, rigorous medical studies to determine the side effects, especially on cardiovascular health are limited. Nevertheless, the researchers warn it is important for users to know it is not a harmless drug, and that it can have serious side effects depending on the conditions, medical circumstances, and other medications being taken.