Is it safe to take melatonin with isosorbide?
No known interactions exist between melatonin and isosorbide (including forms like isosorbide mononitrate or dinitrate, used for angina and heart conditions). Melatonin, a sleep aid, does not appear to affect isosorbide's blood pressure-lowering or nitrate effects.[1][2]
What do drug interaction checkers say?
Tools like Drugs.com and WebMD report no interactions. Melatonin primarily influences sleep-wake cycles via serotonin receptors, while isosorbide dilates blood vessels through nitric oxide—pathways that don't overlap significantly.[1][3]
Could there be indirect effects or risks?
Both can cause drowsiness or dizziness: melatonin promotes sleepiness, isosorbide may trigger headaches or lightheadedness. Combining them might amplify these, increasing fall risk, especially in older adults or those with heart issues. Start with low melatonin doses (0.5-3 mg) at night, away from isosorbide doses.[2][4]
What do doctors recommend?
Consult your doctor or pharmacist before combining, as individual factors like dosage, other meds (e.g., blood thinners), or conditions (e.g., low blood pressure) matter. They can check via tools like Lexicomp.[1][4]
Timing and alternatives if concerned
Take melatonin 30-60 minutes before bed; space from isosorbide if daytime dosing. Alternatives: non-drug sleep aids like CBT-I or diphenhydramine (but check interactions separately).[3]
[1]: Drugs.com - Melatonin and Isosorbide Interactions
[2]: WebMD - Melatonin Interactions
[3]: RxList - Isosorbide Mononitrate
[4]: Mayo Clinic - Melatonin Safety