isosorbide mononitrate
Pregnancy Risk Category C
How supplied
isosorbide dinitrate
Tablets: 5 mg, 10 mg, 20 mg, 30 mg, 40 mg
Tablets (S.L.): 2.5 mg, 5 mg, 10 mg
Tablets (chewable): 5 mg, 10 mg
Tablets (sustained-release): 40 mg
Capsules: 40 mg
Capsules (sustained-release): 40 mg
isosorbide mononitrate
Tablets: 10 mg, 20 mg
Tablets (extended-release): 30 mg, 60 mg, 120 mg
Action
Not completely known. Thought to reduce cardiac oxygen demand by decreasing preload and afterload. Drug also may increase blood flow through the collateral coronary vessels.
Indications & dosage
Acute angina attacks (S.L. and chewable tablets of isosorbide dinitrate only), prophylaxis in situations likely to cause angina attacks--
Adults: S.L. form--2.5 to 5 mg S.L. for prompt relief of angina pain, repeated q 5 to 10 minutes (maximum of three doses for each 30-minute period). For prophylaxis, 2.5 to 10 mg q 2 to 3 hours.
Chewable form--5 to 10 mg, p.r.n., for acute attack or q 2 to 3 hours for prophylaxis, but only after initial test dose of 5 mg to determine risk of severe hypotension.
Oral form (isosorbide dinitrate)--5 to 30 mg P.O. t.i.d. or q.i.d. for prophylaxis only (use smallest effective dose); 20 to 40 mg P.O. (sustained-release) q 6 to 12 hours.
Oral form (isosorbide mononitrate using Imdur)--30 to 60 mg P.O. once daily upon arising; increased to 120 mg once daily after several days, if needed.
Oral form (isosorbide mononitrate using ISMO or Monoket)--20 mg b.i.d. with the two doses given 7 hours apart.
Adverse reactions
CNS: headache; dizziness; weakness.
CV: orthostatic hypotension, tachycardia, palpitations, ankle edema, fainting, flushing.
GI: nausea, vomiting.
Skin: cutaneous vasodilation, rash.
Other: sublingual burning.
Interactions
Drug-drug. Antihypertensives: may increase hypotensive effects. Monitor closely during initial therapy.
Sildenafil: may increase hypotensive effects. Avoid concomitant use.
Drug-lifestyle. Alcohol use: may increase hypotension. Avoid concomitant use.
Effects on diagnostic tests
May interfere with serum cholesterol determination tests using the Zlatkis-Zak color reaction, causing a falsely decreased value.
Contraindications
Contraindicated in patients with hypersensitivity or idiosyncrasy to nitrates, severe hypotension, angle-closure glaucoma, increased intracranial pressure, shock, or acute MI with low left ventricular filling pressure.
Nursing considerations
Patient teaching
*Liquid contains alcohol. **May contain tartrazine. †Canada ‡Australia §U.K. OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING