If you are currently being treated with any of the following medications, you
should not use melatonin without first talking to your healthcare provider.
In an animal study, melatonin
supplements reduced the antidepressant effects of desipramine and fluoxetine.
More research is needed to determine whether these effects would occur in
people. In addition, fluoxetine (a member of a class of drugs called selective
serotonin reuptake inhibitors or SSRIs) has led to measurable depletion of
melatonin in people.
A common side effect of
antipsychotic medications used to treat schizophrenia is a condition called
tardive dyskinesia, a movement disorder of the mouth characterized by a constant
chewing motion and darting action of the tongue. In a study of 22 people with
schizophrenia and tardive dyskinesia caused by antipsychotic medications, those
who took melatonin supplements had significantly reduced mouth movements
compared to those who did not take the supplements.
The combination of melatonin and triazolam (a
benzodiazepine medication used for the treatment of anxiety and sleep disorders)
improved sleep quality in one study. In addition, there have been a few reports
suggesting that melatonin supplements may help individuals stop using long-term
benzodiazepine therapy. (Benzodiazepines are highly addictive.)
Blood Pressure Medications
Melatonin may reduce the
effectiveness of blood pressure medications like methoxamine and clonidine. In
addition, medications in a class called calcium channel blockers (such as
nifedipine, verapamil, diltiazem, amlodipine, nimodipine, felodipine,
nisoldipine, and bepridil) may decrease melatonin levels.
Use of beta-blockers (another class of high blood pressure medications
including propranolol, acebutolol, atenolol, labetolol, metoprolol, pindolol,
nadolol, sotalol, and timolol) may reduce melatonin production in the body.
Blood-thinning Medications, Anticoagulants
increase the risk of bleeding from anticoagulant medications such as warfarin.
In one study of 80 cancer patients, use of
melatonin in conjunction with interleukin-2 led to more tumor regression and
better survival rates than treatment with interleukin-2 alone.
Nonsteroidal Anti-inflammatory Drugs (NSAIDs)
NSAIDs such as
ibuprofen may reduce the levels of melatonin in the blood.
Steroids and Immunosuppressant Medications
not be taken with corticosteroids or other medications used to suppress the
immune system because the supplement may cause them to be ineffective.
Preliminary research suggests that the combination
of tamoxifen (a chemotherapy drug) and melatonin may benefit certain patients
with breast and other cancers. More research is needed to confirm these results.
Caffeine, tobacco, and alcohol can all
diminish levels of melatonin in the body while cocaine and amphetamines may
increase melatonin production.