Diclegis Drug Interactions

Known or theoretical interactions with antihistamines of the ethanolamine class: Anticholinergic agents (tricyclic antidepressants, MAOI, neuroleptics): may enhance toxicity due to the addition of their anticholinergic effects.
Sedatives (barbiturates, benzodiazepines, antipsychotic agents, opioid analgesics): may enhance the hypnotic action.
Antihypertensive drugs with sedative effect on the CNS (especially alphamethyldopa) because they may enhance the sedative effect when administered with antihistamines.
Alcohol: enhanced toxicity, with altered intellectual and psychomotor capacity, has been reported in some studies. The mechanism has not been established.
Sodium oxybate as a not recommended combination with doxylamine due to its important central depressant effect.
Ototoxic medications: Sedating antihistamines of the ethanolamine class, like doxylamine, could mask the warning signs of damage caused by ototoxic drugs such as antibacterial aminoglycosides.
Photosensitizing medications: The concurrent use of antihistamines with other photosensitizing medications such as amiodarone, quinidine, imipramine, doxepin, amitriptyline, griseofulvin, chlorpheniramine, piroxicam, furosemide, captopril among others, may cause additive photosensitizing effects.
Since several antihistaminic agents may prolong the QT interval, although this effect has not been observed with doxylamine at therapeutic dose, concomitant use of drugs that prolong the interval should be avoided (e.g. antiarrhythmic drugs, certain antibiotics, certain drugs for malaria, certain antihistaminic drugs, certain antilipidemic drugs or certain neuroleptic agents).
Concomitant use of cytochrome P-450 inhibitors should be avoided (e.g. azole derivatives or macrolides).
Concomitant use of drugs that cause electrolyte disturbances such as hypokalemia or hypomagnesemia (e.g. some diuretics) should be avoided.
The anticholinergic effects of doxylamine, a component of this medicinal product, could lead to false negatives in dermal hypersensitivity tests with antigen extracts. It is recommended to discontinue the treatment several days before starting the test.
Known or theoretical interactions with pyridoxine: Reduce the effect of levodopa although it does not occur if co-administered with an inhibitor of dopa decarboxylase.
It has been described a reduction in plasma levels of some antiepileptics such as phenobarbital and phenytoin.
Some medications such as hydroxyzine, isoniazid or penicillamine may interfere with pyridoxine and may increase requirements for vitamin B6.
Food: A food-effect study has demonstrated that the delay in the onset of action of this medicinal product may be further delayed, and a reduction in absorption may occur when tablets are taken with food. Therefore, this medicinal product should be taken on an empty stomach with a glass of water (see Dosage & Administration).
Interference with urine screen for Methadone, Opiates and PCP: False positive urine drug screens for methadone, opiates, and PCP can occur with doxylamine hydrogen succinate/pyridoxine hydrochloride use. Confirmatory tests, such as Gas Chromatography Mass Spectrometry (GC-MS), should be used to confirm the identity of the substance in the event of a positive immunoassay result.