7 Medications That Don’t Mix Well With Herbal Tea

Not only are herbal teas delicious and soothing, but they can also help with digestion, immune support, and sleep. However, it’s important to know what you are consuming, as many herbals can interact with prescription medications.

1. Cyclosporine

Cyclosporine is an immunosuppressant that is used after an organ transplant to prevent organ rejection. It is also used for severe psoriasis or rheumatoid arthritis.

Cyclosporine use requires frequent blood level monitoring to ensure the medication works properly. If levels are too low, it can result in organ rejection, while high levels can cause toxicity.

Herbal ingredients, such as St. John’s wort and ginger, can decrease the effectiveness of cyclosporine, making it less likely to work as intended. There have been case reports linking St. John’s wort use with transplant rejection.

Other herbal medications, such as chamomile and echinacea, can increase the effect of cyclosporine, causing side effects and toxicity.

2. Blood Thinners and Antiplatelets

Warfarin is a blood thinner used to treat and prevent blood clots in certain individuals.  Warfarin requires frequent monitoring of the International Normalized Ratio (INR), or the rate at which blood clots.

Direct oral anticoagulants are newer blood thinners that do not require frequent INR monitoring. They include the following medications:

• Eliquis (apixaban)
• Pradaxa (dabigatran)
• Xarelto (rivaroxaban)
• Savaysa (edoxaban)

Antiplatelet medications prevent blood clots by stopping platelets from sticking together. Antiplatelet medications include:

• Aspirin
• Plavix (clopidogrel)
• Effient (prasugrel)
• Brilinta (ticagrelor)

Any herbal medication that can affect bleeding or clotting should be avoided by those who take blood thinners or antiplatelet medications. These could either increase the risk of bleeding or increase the risk of blood clots.

Examples of herbal ingredients that may interact include:

• Cranberry
• Cinnamon
• Ginger
• Gingko
• Ginseng
• St John’s wort
• Turmeric

One case report showed that cinnamon and ginger can increase the bleeding risk when used with these medications. St. John’s wort, on the other hand, can decrease the effectiveness and lead to blood clots.

3. Digoxin

Digoxin is used to treat heart failure and certain types of irregular heartbeats. Digoxin is a medication with a narrow therapeutic index, meaning that digoxin levels must be regularly monitored. High digoxin levels can lead to severe side effects and toxicity.

St. John’s wort can decrease how well digoxin works. Although data are lacking, other herbal ingredients that may interfere with digoxin’s effectiveness include:

4. Antidepressants

Antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs), increase serotonin levels in the brain to improve mood and behavior.

Both ginseng and St John’s wort may increase serotonin levels. When used with an SSRI or SNRI, these herbs could lead to serotonin syndrome. This is when serotonin levels are too high and can lead to confusion, increased heart rate, fever, or seizures.

5. Benzodiazepines

Benzodiazepines include medications such as alprazolam, diazepam, and clonazepam. They are used to manage anxiety symptoms in people with anxiety disorders.

A common side effect of benzodiazepines is drowsiness and sedation. Valerian root, a common ingredient in nighttime sleepy teas, can also cause drowsiness. When taken together, these side effects can be increased and could lead to dangerous central nervous system depression.

St. John’s wort can also decrease how well benzodiazepines work and should be avoided.

6. Metformin

Metformin is a popular medication used to manage blood sugar in people with type 2 diabetes. Goldenseal, which is used for digestive and immune system support, can decrease the effect of metformin, leading to poor glucose control.

7. Blood Pressure Medications

Berberine is a compound found in many herbs, including barberry, goldenseal, and turmeric. It has been shown to help lower blood pressure.

A study involving rats showed that when berberine and losartan are administered together, berberine increases the concentration of losartan in the body. This can cause low blood pressure and increased side effects.

The effects of ginseng on blood pressure are conflicting. Some reports indicate decreases in blood pressure, while others suggest that ginseng can help normalize low blood pressure. Interactions with blood pressure medications also show mixed results, so it is best to avoid.

Safety

In the US, herbal teas are regulated as dietary supplements, meaning they are not required to be tested for correct ingredients or contaminants before they are made available for sale. It is important to choose a high-quality tea brand, preferably one that tests its products for heavy metals, pesticides, and other harmful substances.

Over-the-counter (OTC) medications, supplements, vitamins, and herbals can interact with prescription medications. It is important to speak with your healthcare provider or pharmacist before adding them to your routine. They can make sure it will be beneficial for you and will not interact with your other medications.