Primarily a venous dilator (lesser degree - arteriolar dilator). It may be most useful in patients with symptomatic coronary disease and in those with hypertension following coronary bypass. Drug of choice for hypertensive emergencies with coronary ischemia. It should not be used with hypertensive encephalopathy because it increases ICP. Tolerance may occur within 24-48 hours. Nitrate-free interval (10-12 hours/day) is recommended to avoid tolerance development.
(IV): Initial dose: 5 mcg/min IV infusion. Increase by 5 mcg/minute every 3-5 minutes to 20 mcg/minute. If no response at 20 mcg/minute increase by 10 mcg/minute every 3-5 minutes, up to a maximum of 200 mcg/minute. Onset: 2 to 5 minutes. Duration: 5 to 10 minutes.
Initial increments of 5 micrograms/minute can be made every 3 to 5 minutes. If no response is seen at 20 micrograms/minute, larger increments of 10 to 20 micrograms/minute can be considered. As partial response is achieved, dosing increments should become more cautious.
Angina/coronary artery disease:
Oral: 2.5mg to 9 mg bid - qid (up to 26 mg qid). Topical ointment: Apply 0.5" to 2" every 6 hours with a nitrate free interval (10-12hrs). Patch (transdermal): 0.2-0.4 mg/hour initially and titrate to doses of 0.4-0.8 mg/hour. Remove patch to provide nitrate free interval (10-12hrs). Sublingual: 0.2-0.6 mg every 5 minutes for maximum of 3 doses in 15 minutes.
Esophageal spastic disorders (unlabeled use): 0.3-0.4 mg 5 minutes before meals. Translingual: 1-2 sprays into mouth under tongue every 3-5 minutes for maximum of 3 doses in 15 minutes, may also be used 5-10 minutes prior to activities which may provoke an attack prophylactically.
Supplied: Capsule (ER): 2.5 mg, 6.5 mg, 9 mg. Injection (Soln): 5 mg/ml (5 ml, 10 ml). Ointment: 2% (1 g, 30 g, 60 g). Sublingual tablet: 0.3 mg, 0.4 mg, 0.6 mg. Patch (Transdermal ): 0.1 mg/hour; 0.2 mg/hour; 0.4 mg/hour; 0.6 mg/hour.