For many people, coffee is a necessary part of the morning routine, perking us up for the day ahead. Some studies suggest that coffee may, in fact, have health benefits, such as reduced risk of stroke, but the caffeine in coffee, tea, soft drinks and energy drinks can also cause health problems, such as increased gastric acidity leading to acid reflux. And that delightful little “cuppa joe” interacts with a surprising number of common medications.
Caffeine has been shown to increase blood levels of duloxetine, a medication used for depression, nerve pain, fibromyalgia, and other conditions. Higher levels of duloxetine could increase the risk of serotonin syndrome, especially if taking at the same time as other medications that can increase serotonin levels (e.g., cough suppressants, St John’s Wort, specific street drugs). It may also increase levels of ropinirole, a treatment for Parkinson’s, thus worsening side effects.
On the other hand, caffeine has been shown to reduce the effectiveness of methotrexate, which is commonly used for rheumatoid arthritis, so for this reason it would be wise to limit caffeine-containing beverages and foods. There are case studies showing reduced absorption of levothyroxine when individuals drink coffee immediately before or after taking this thyroid medication; while case studies are not definitive, changing the time when you take levothyroxine could improve drug response. Similarly, the osteoporosis medication alendronate should be taken on an empty stomach; taking it with coffee has been shown to significantly reduce absorption.
Some medications, such as echinacea, lithium or the antibiotic ciprofloxacin, can increase blood levels and effects of caffeine. This could lead to increased blood pressure and heart rate, restlessness, insomnia, and irritability. Be mindful also when taking over-the-counter stimulants, such as weight loss pills. OTC diuretics (water pills) are usually just caffeine, so you could be taking more than you intended.
You can find a list of some of the medications that caffeine interacts with online. Not all interactions are significant or even warrant consideration. When picking up your medications — even refills of drugs that you have taken for some time — chat with your pharmacist for a couple minutes. We are here to help you get the most benefit from your prescriptions. We are also happy to sit down with you for a more formal medication review, where we can discuss any over-the-counter medications, vitamins, and natural health supplements that you are taking.