Class: Long-Acting Nitrate, Anti-Anginal
Dosage Forms. Extended-Release Tablet: 30 mg, 60 mg, 120 mg; Immediate-Release Tablet (ISMO, Monoket): 10 mg, 20 mg
Common FDA Label Indication, Dosing, and Titration.
1. Angina, prophylaxis: Adults: (Extended Release) initial, 30-60 mg po daily; maintenance, 120-240 mg po daily; (Immediate Release): 20 mg bid separated 7 h apart
Off Label Uses. None
MOA. Isosorbide mononitrate (ISMN) is the active 5-mononitrate metabolite of isosorbide dinitrate. Nitroglycerin and other organic nitrates are converted to nitric oxide (NO) by vascular endothelium. NO activates guanylate cyclase, increasing cyclic GMP that in turn decreases intracellular calcium, resulting in direct relaxation of vascular smooth muscle.
Drug Characteristics: Isosorbide Mononitrate
Medication Safety Issues: Isosorbide Mononitrate
Drug Interactions: Isosorbide Mononitrate
Adverse Reactions: Isosorbide Mononitrate
Efficacy Monitoring Parameters. Decreased use of sublingual nitroglycerin, reduction in angina episodes.
Toxicity Monitoring Parameters. Report signs/symptoms of hypotension, problematic headaches, or decreasing efficacy (drug tolerance) to prescriber.
Key Patient Counseling Points. It is best to take this medicine on an empty stomach with at least half a glass of water. Swallow the extended-release tablet whole. Do not break, crush, or chew it. This medicine can cause headaches, which is a sign that the medicine is working. Acetaminophen may be used to relieve the headache. Talk with your doctor if the headache is severe. This medicine can cause dizziness. Avoid driving, using machines, or doing anything else that could be dangerous if not alert. Stand up slowly if this medicine causes lightheadedness from orthostatic hypotension. Do not stop using this medicine suddenly without asking a healthcare provider. The dose may need to be slowly decreased before stopping it completely. Avoid concomitant use of erectile dysfunction medications as this may increase risk of severe hypotension. Avoid drinking alcohol while taking this drug.
Clinical Pearls. Safety and efficacy have not established in children. Combining long-acting nitrates with antihypertensive medications can increase risk of hypotension. To avoid tolerance, include an 8-h nitrate free interval in every 24-h period.