ISOSORBIDE DINITRATE
(eye-soe-sor'bide)
Coronex , Dilatrate-SR, Iso-Bid, Isordil, Isotrate, Novosorbide , Sorbitrate, Sorbitrate SA
Classifications: cardiovascular agent; nitrate vasodilator
Prototype: Nitroglycerin
Pregnancy Category: C

Availability

2.5 mg, 5 mg, 10 mg sublingual tablets; 5 mg, 10 mg chewable tablets; 5 mg, 10 mg, 20 mg, 30 mg, 40 mg tablets; 40 mg sustained release tablets, capsules

Actions

Organic nitrate with pharmacologic actions similar to those of nitroglycerin. Relaxes vascular smooth muscle with resulting vasodilation. Dilation of peripheral blood vessels tends to cause peripheral pooling of blood, decreased venous return to heart, and decreased left ventricular end-diastolic pressure, with consequent reduction in myocardial oxygen consumption.

Therapeutic Effects

Has an antianginal effect by causing vasodilation of the coronary arteries.

Uses

Relief of acute anginal attacks and for management of long-term angina pectoris.

Unlabeled Uses

Alone or in combination with a cardiac glycoside or with other vasodilators (e.g., hydralazine, prazosin, for refractory CHF; diffuse esophageal spasm without gastroesophageal reflux and heart failure).

Contraindications

Hypersensitivity to nitrates or nitrites; severe anemia; head trauma; increased intracranial pressure. Safe use during pregnancy (category C) or lactation is not established.

Cautious Use

Glaucoma, hypotension, hyperthyroidism.

Route & Dosage

Angina Prophylaxis
Adult: PO Regular tablets 2.5–30 mg q.i.d. a.c. and h.s.; Sublingual tablet 2.5–10 mg q4–6h; Chewable tablet 5–30 mg chewed q2–3h; Sustained release tablets 40 mg q6–12h

Acute Anginal Attack
Adult: PO Sublingual tablet 2.5–10 mg q2–3h prn; Chewable tablet 5–30 mg chewed prn for relief

Administration

Oral

Adverse Effects (1%)

Body as a Whole: Hypersensitivity reaction, paradoxical increase in anginal pain, methemoglobinemia (overdose). CNS: Headache, dizziness, weakness, lightheadedness, restlessness. CV: Palpitation, postural hypotension, tachycardia. GI: Nausea, vomiting. Skin: Flushing, pallor, perspiration, rash, exfoliative dermatitis.

Interactions

Drug: Alcohol may enhance hypotensive effects and lead to cardiovascular collapse; antihypertensive agents, phenothiazines add to hypotensive effects.

Pharmacokinetics

Absorption: Significant first pass metabolism with PO absorption, with 10–90% reaching systemic circulation. Onset: 2–5 min SL; within 1 h regular tabs; within 3 min chewable tabs; 30 min sustained release tabs. Duration: 1–2 h SL; 4–6 h regular tabs; 0.5–2 h chewable tabs; 6–8 h sustained release tabs. Metabolism: Metabolized in liver. Elimination: 80–100% excreted in urine within 24 h.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education


Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug