Heart & blood pressure
Nitrate
Isosorbide mononitrate
Also known as: Imdur, Monoket
Best time
Morning & early afternoon (asymmetric)
- 07:00–09:00· First dose
- 14:00–16:00· Second dose (immediate-release)
Doses are bunched in the daytime to leave a nitrate-free gap overnight so the drug keeps working.
Strong evidence
Consistent clinical trials or official prescribing guidance support this timing.
Why this time works
The body becomes tolerant to continuous nitrates. Immediate-release tablets are taken ~7 hours apart (e.g. 08:00 and 15:00) to create a long night-time gap; once-daily modified-release tablets are taken in the morning.
Body rhythm involved
Angina episodes cluster in the morning hours.