Interactions

Possible drug interactions include:

• Anticoagulants and anti-platelet drugs, herbs and supplements. These types of drugs, herbs and supplements reduce blood clotting. Combining use of melatonin with them might increase the risk of bleeding.
• Anticonvulsants. Melatonin might inhibit the effects of anticonvulsants and increase the frequency of seizures particularly in children with neurological disabilities.
• Blood pressure drugs. Melatonin might worsen blood pressure in people taking blood pressure medications.
• Central nervous system (CNS) depressants. Melatonin use with these medications might cause an additive sedative effect.
• Diabetes medications. Melatonin might affect sugar levels. If you take diabetes medications, talk to your doctor before using melatonin.
• Contraceptive drugs. Use of contraceptive drugs with melatonin might cause an additive sedative effect and increase possible side effects of melatonin.
• Cytochrome P450 1A2 (CYP1A2) and cytochrome P450 2C19 (CPY2C19) substrates. Use melatonin cautiously if you take drugs such as diazepam (Valium, Valtoco, others) and others that are affected by these enzymes.
• Fluvoxamine (Luvox). This medication used to treat obsessive-compulsive disorder can increase melatonin levels, causing unwanted excessive drowsiness.
• Immunosuppressants. Melatonin can stimulate immune function and interfere with immunosuppressive therapy.
• Seizure threshold lowering drugs. Taking melatonin with these drugs might increase the risk of seizures.