Ismo, Imdur, Monoket
Classifications: nitrate vasodilator; Therapeutic: vasodilator; nitrate
Pregnancy Category: C
10 mg, 20 mg tablets; 30 mg, 60 mg, 120 mg sustained release tablets
Isosorbide mononitrate is a long-acting metabolite of the coronary vasodilator isosorbide dinitrate. It decreases preload
as measured by pulmonary capillary wedge pressure (PCWP), and left ventricular end volume and diastolic pressure (LVEDV),
with a consequent reduction in myocardial oxygen consumption.
It is equally or more effective than isosorbide dinitrate in the treatment of chronic, stable angina. It is a potent vasodilator
with antianginal and antiischemic effects.
Prevention of angina. Not indicated for acute attacks.
Hypersensitivity to nitrates; severe anemia; closed-angle glaucoma; recent MI; postural hypotension, head trauma, cerebral
hemorrhage (increases intracranial pressure); pregnancy (category C). Extended form should not be used in patients with
Older adults, hypotension; lactation.
Route & Dosage
|Prevention of Angina
Adult: PO Regular release (ISMO, Monoket) 20 mg b.i.d. 7 h apart; Sustained release (Imdur) 3060 mg every morning, may increase
up to 120 mg once daily after several days if needed (max: dose 240 mg)
- Give first dose in morning on arising and second dose 7 h later with twice daily dosing regimen. Give in morning on arising
with once daily dosing.
- Store sustained release tablets in a tight container.
Adverse Effects (≥1%)CNS:
Headache, agitation, anxiety, confusion, loss of coordination, hypoesthesia, hypokinesia, insomnia
or somnolence, nervousness,
migraine headache, paresthesia
, vertigo, ptosis, tremor. CV:
Aggravation of angina, abnormal heart sounds, murmurs, MI,
transient hypotension, palpitations. Hematologic:
, purpura, thrombocytopenia
, methemoglobinemia (high doses). GI:
Nausea, vomiting, dry mouth, abdominal pain, constipation
, dyspepsia, flatulence, tenesmus, gastric ulcer, hemorrhoids,
, glossitis. Metabolic:
Hyperuricemia, hypokalemia. GU: Renal
calculus, UTI, atrophic vaginitis
, dysuria, polyuria, urinary frequency, decreased libido, impotence. Respiratory: Bronchitis
, upper respiratory tract infection
, nasal congestion, bronchospasm, coughing, dyspnea
, rales, rhinitis. Skin:
Rash, pruritus, hot flashes, acne
, abnormal texture. Special Senses: Diplopia
, blurred vision, photophobia, conjunctivitis
may cause severe hypotension and cardiovascular collapse. Aspirin
may increase nitrate serum
levels. calcium channel blockers
may cause orthostatic hypotension.
Completely and rapidly absorbed from GI tract; 93% reaches systemic circulation. Onset:
1 h. Peak:
Regular release 3060 min; sustained release 34 h. Duration:
Regular release 512 h; sustained release 12 h. Metabolism:
In liver by denitration and conjugation to inactive metabolites. Elimination:
Primarily by kidneys. Half-Life:
Assessment & Drug Effects
- Monitor cardiac status, frequency and severity of angina, and BP.
- Assess for and report possible S&S of toxicity, including orthostatic hypotension, syncope, dizziness, palpitations, light-headedness,
severe headache, blurred vision, and difficulty breathing.
- Lab tests: Monitor serum electrolytes periodically.
Patient & Family Education
- Do not crush or chew sustained release tablets. May break tablets in two and take with adequate fluid (48 oz).
- Do not withdraw drug abruptly; doing so may precipitate acute angina.
- Maintain correct dosing interval with twice daily dosing.
- Note: Geriatric patients are more susceptible to the possibility of developing postural hypotension.
- Avoid alcohol ingestion and aspirin unless specifically permitted by physician.