Mixing Drugs and Vitamins: What Are the Dangers?

by Dr. Stephen Sinatra

Filed Under: General Health

Last Reviewed 03/04/2013

Many people ask me about taking various vitamins and herbs with pharmacological drugs. Be assured that most vitamin and mineral supplements, including coenzyme Q10, can be taken with drugs.
I've been mixing conventional drugs with vitamin and mineral supplements for more than 20 years and, generally speaking, most of my patients have used combinations of vitamins and minerals and conventional drugs without any undue side effects.
That doesn't mean you shouldn't be cautious, however. The literature is loaded with studies demonstrating that herbs—like drugs—can trigger adverse and dangerous reactions.
With the following exceptions, most herbs and drugs can be safely mixed.

Drug/Vitamin/Herb Mixtures You Should Avoid

• Never take long-acting niacin if you take statin-like drugs. A combination of the two could cause excessive metabolic stress to the liver. Remember, long-acting niacin in gram doses acts like a drug (don't worry if you're taking small doses of short-acting preparations).
• Do not take standard dosages of ginkgo biloba (120–240 mg daily) if you're on Coumadin.
• If you're on Digoxin, take hawthorn berry only under a physician's guidance. This combo could cause your heart rate to slow too much.
• If you're taking Digoxin with beta blockers, stay away from large doses of vitamin E (more than 800 IU) and magnesium (more than 600 mg), as a combination of this mixture may cause additional heart-rate slowing.
• Never use Kava Kava or St. John's wort, natural supplements for depression, with anti-depression drugs like Paxil, Prozac or Zoloft. An overdose of serotonin, the brain's happy hormone, may occur, resulting in serotonin excess, which manifests itself as irritability, dry mouth, and insomnia.
• Do not use the herbs valerian root or passion flower if you take tranquilizers like Valium or Xanax because this combination can make you drowsy.