1-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.2-Anticonvulsants. Melatonin might inhibit the effects of anticonvulsants and increase the frequency of seizures particularly in children with neurological disabilities.3-Blood pressure drugs. Melatonin might worsen blood pressure in people taking blood pressure medications.4-Central nervous sy