Green Tea Interactions With Medications (What You Need To Know)

We all know green tea is healthy.

But it also has some potential side effects.

And there are possible green tea interactions with medications you need to worry about, too.

Generally, you won’t have any issues if you just drink a cup or two per day.

Nevertheless, it pays to know about possible issues with certain medications.

And if you are taking any of those medications, it is always best to consult with your doctor about possible issues with green tea.

What medications do you need to worry about? Keep reading to find out. We will cover the main ones and tell you everything you need to know about their potential to interact with green tea.

 

Green Tea Drug Interactions

As mentioned, if you are taking any of the following medications, I strongly recommend consulting with a medical professional if you plan to drink green tea regularly, especially if you drink many cups a day.

 

Blood Pressure Medicines

Blood pressure (BP) medications include beta-blockers like Propranolol and Metoprolol. Different blood pressure medicines work in different ways to lower high blood pressure.

For example, some BP medicines, like diuretics, expel excess water and salts from the body. Some others relax the blood vessels.

It is best not to drink too much green tea if you are taking such medications to lower blood pressure. The caffeine in green tea could interact with these medicines and reduce their efficacy.

Caffeine also increases blood pressure and heart rate. Even if your blood pressure is low, you should limit your green tea intake to no more than 1 to 2 cups a day.

 

Blood Thinners

Blood thinners are prescribed when you have a blood clot. Blood clots tend to increase your risk of heart attacks. A blood thinner drug prevents the clot from getting bigger.

These drugs usually include anticoagulants like Warfarin (Coumadin) or painkillers like aspirin. They could also include antiplatelet medications like Dipyridamole (Persantine) that stop the blood cells from sticking together and forming a blood clot.

Green tea contains several compounds, including vitamin K, which slow down blood clotting. If you are taking a blood thinner along with several cups of green tea, you could increase your risk of bleeding. So make sure you check with your doctor if it is okay to drink green tea in moderation when taking a blood thinner.

 

Estrogen

Estrogen is prescribed to treat estrogen deficiency or to suppress lactation in women. It may also be prescribed to men with certain cancers.

It is best not to consume too many caffeinated beverages, including green tea, while on estrogen therapy, because estrogen impacts how the body breaks down caffeine.

As a result, you could suffer from the side effects of caffeine including jitteriness, headaches, insomnia, heart palpitations, etc.

 

Statins

Statins (brand names Lipitor, Crestor, Altoprev, Zocor, Lescol XL, and Livalo) are cholesterol-lowering drugs. They are prescribed to reduce the risk of heart attacks and strokes.

Green tea and green tea extracts decrease the absorption of statins, like rosuvastatin and simvastatin, and increase their levels in the blood. This could result in muscle pain and even kidney and/or liver damage, in extreme cases.

If you have been prescribed statins, please check with your doctor regarding consuming green tea.

 

Stimulant Drugs

Stimulant drugs (amphetamines) are prescribed to increase the activity of the central nervous system. People take some stimulants, like cocaine, for recreational purposes as well. They make you feel more awake, confident, alert, and energetic.

You should not take green tea with stimulant drugs, because it contains caffeine which is also a stimulant. Taking green tea with stimulant drugs could accelerate your heartbeat and increase blood pressure.

 

Benzothiazole Drugs

Benzothiazole drugs, like Riluzole, are used for the treatment of ALS (amyotrophic lateral sclerosis), also known as Lou Gehrig’s disease.

The disease causes symptoms like loss of motor control, twitching and tightness of muscles, muscle cramps, etc. In its later stages, the disease results in advanced loss of motor function.

When taking Riluzole for ALS, it is best to avoid green tea. Green tea is known to decrease how quickly the body breaks down this medicine. It can interfere with the drug’s efficacy and also exacerbate its effects and side effects.

 

Bronchodilators

Bronchodilators, like theophylline and anticholinergic drugs like ipratropium, tiotropium, aclidinium, and glycopyrronium, are prescribed to relax the airways in conditions where they become narrow and inflamed. These mainly include asthma and chronic obstructive pulmonary disease (COPD).

However, their side effects include a stimulant effect on the heart. Green tea contains caffeine, which is also a stimulant known to increase the heart rate. Too much green tea taken with asthma medications could result in heart-related issues in some people.

 

Anti-Cancer Drugs (Proteasome Inhibitors)

Anticancer drugs, like Ninlaro (ixazomib) and Velcade (bortezomib), target tumor cells and cause them to die. According to the Cancer Research UK website, green tea is an herbal product that has not undergone the required number of tests to ensure it is safe to drink while taking cancer drugs.

Like any other herbal product, green tea could increase or decrease the cancer medicines’ efficacy. It could also change the way certain drugs work.

One study conducted in 2013 showed that the catechins in green tea increase the action of certain cancer medicines, while reducing the effect of other medicines. It is best to speak with your physician before consuming large quantities of green tea when undergoing cancer treatment.

 

Adenosine

Adenosine medicines are often prescribed before cardiac stress tests to relax heart rhythm. Doctors also prescribe these drugs for people with heart rhythm disorders (irregular or unsteady heartbeat) as they help relax and dilate blood vessels. Experts recommend not having green tea while taking adenosine medicines, since it could reduce their efficiency.

 

Antacids

Antacids, or heartburn drugs, reduce the level of stomach acids. It is best not to consume too much tea, including green tea, since it increases stomach acids due to its caffeine content.

If you are taking antacids to counteract excess stomach acids, it is also important to reduce your intake of acidity-causing foods, including caffeinated beverages like green tea.

 

Antibiotics Like Quinolone

Quinolones are broad-spectrum antibiotics used for treating urinary tract infections. Quinolone is known to interfere with the way the body breaks down caffeine. Therefore, it is best to limit your intake of caffeinated beverages like green tea when you are taking quinolone.

Also, quinolone is known to result in side effects like headaches and insomnia, which are also the side effects of caffeine. So, please check with your healthcare provider if consuming green tea while on quinolone is safe for you.

 

Sleep-Aids (Pentobarbital)

Pentobarbital (Nembutal) is a sleep aid used for treating insomnia and seizures or convulsions. The sedative is also used before surgery as an anesthetic.

It is best not to drink any caffeinated beverages, including green tea, while taking pentobarbital (Nembutal). This is because caffeine counteracts the drug and blocks its sleep-producing effects.

 

Green Tea Interactions With Medications: Final Thoughts

While green tea has numerous health benefits, there is also the potential for significant green tea interactions with medications. These interactions may range from affecting the efficacy of blood pressure medications and blood thinners to altering the metabolism of drugs such as statins, estrogen, and certain cancer treatments.

The caffeine content in green tea can interfere with stimulant drugs, bronchodilators, and even sleep aids. Additionally, compounds in green tea, like vitamin K, can affect the action of anticoagulants and other medications.

It is crucial to consult with your healthcare provider before consuming green tea, especially in large quantities, if you are on any medication that may be affected. You want to make sure drinking green tea does not compromise your treatment or exacerbate any conditions.

Moderation and medical guidance are key to safely enjoying the benefits of green tea without risking adverse drug interactions. And if your doctor tells you to avoid green tea altogether, check out our article on good alternative drinks to green tea.