Written by Karen Moeller, PharmD, BCPP
My doctor recently started me on lithium and told me there are lots of drug interactions with this medication. My pharmacist is very good at telling me about interactions with prescription medications but how do I know which non-prescription or over-the-counter medications to avoid?
Great question! First, if you have any questions regarding non-prescription medications (also known as over the counter medications) or herbal medications, your pharmacist can help answer those questions for you. Pharmacists are experts on both prescription and non-prescription medications. Never be afraid to ask your pharmacist a question; we love to help.
Your doctor is right about lithium having many drug interactions. It is always important that you let ALL your doctors, including dentists and pharmacists, know you are taking lithium in order to avoid potential drug interactions.
As for over-the counter medications that can interact with lithium, the most common drug interactions with lithium are with the Nonsteroidal Anti-Inflammatory Agents (NSAIDs) that are often used to treat aches and pains. When combined with lithium, NSAIDs can increase lithium levels in the blood resulting in an increased risk for serious adverse effects like confusion, tremor, slurred speech, and vomiting. Examples of non-prescription NSAIDs include:
There are also many prescription NSAIDs such as the following:
In general, it is best to avoid the NSAIDS listed above when taking lithium. Certainly, they should not be used frequently or on a regular basis without consultation with your doctor(s).
If you do need a pain reliever while taking lithium, acetaminophen (Tylenol®) or aspirin (Bayer®, Bufferin®, Ecotrin®) are safe alternatives. Sulindac (Clinoril®), a prescription pain reliever, can also be used as an alternative.
Also, too much caffeine can decrease the effectiveness of lithium and possibly increase your symptoms.
When buying any non-prescription medication it is very important to look at the active ingredients on the package. Many non-prescription medications, such as those used to treat the cold and flu, contain multiple active ingredients and may interact with your medication. For example, Advil Cold and Flu® contains ibuprofen which can increase your lithium level. Also, read the labeling information on all non-prescription medications; this may help avoid drug interactions. When reading the active ingredients list on non-prescription medications or when in doubt about any drug interaction, ask your pharmacist!