Classifications: cardiac inotropic agent; vasodilator; Therapeutic: cardiac inotropic agent
Pregnancy Category: C
5 mg/mL injection
A cardiac inotropic agent with vasodilator activity. Mode of action appears to differ from that of the digitalis glycosides
and beta-adrenergic stimulants. In patients with depressed myocardial function, it enhances myocardial contractility, increases
cardiac output and stroke volume, and reduces right and left ventricular filling pressure, pulmonary capillary wedge pressure
(PCWP), and systemic vascular resistance.
It reduces preload and afterload by its direct relaxant effect on vascular smooth muscle. Inamrinone produces hemodynamic
improvements as well as symptomatic relief in patients in CHF due to ischemic heart disease.
Short-term management of CHF in patients not adequately controlled by traditional therapy, such as digitalis, diuretics,
and vasodilators, and may be used in conjunction with these agents.
Hypersensitivity to inamrinone or to bisulfites; severe aortic or pulmonic valvular disease in lieu of appropriate surgery,
acute MI; uncorrected hypokalemia or dehydration; pregnancy (category C). Safe use in children is not established.
Compromised renal or hepatic function, arrhythmias, hypertrophic subaortic stenosis; decreased platelets; lactation. Concomitant
cardiac glycoside therapy recommended in patients with atrial flutter or fibrillation.
Route & Dosage
|Congestive Heart Failure
Adult: IV 0.75 mg/kg bolus given slowly over 23 min, then start infusion at 510 mcg/kg/min, may repeat bolus in 30 min
(max: 10 mg/kg/d)
Clcr <10 mL/min: give 5075% of dose
PREPARE: Direct: Give loading dose undiluted or diluted by adding 1 mL of NS or 0.45% NS to each 5 mg (1 mL). IV Infusion: ??Dilute 300 mg (60 mL) in 60 mL of NS or 0.45% NS to yield 2.5 mg/mL.??Natural color is clear yellow. Discard discolored solutions and those with precipitate.
ADMINISTER: Direct: Give loading dose over 23 min. May inject into a running D5W infusion through Y-connector or directly. IV Infusion: ??Give diluted solution at a rate of 510 mg/kg/min.??Use infusion pump to regulate rate.
INCOMPATIBILITIES Solution/additive: Sodium bicarbonate, dextrose-containing solutions. Y-site: Furosemide, sodium bicarbonate.
- Use all diluted solutions within 24 h.
- Protect ampules from light.
Adverse Effects (≥1%)Body as a Whole:
Hypersensitivity (pericarditis, pleuritis; myositis with interstitial shadows on chest x-ray and elevated sedimentation
rate; vasculitis with nodular pulmonary
densities, hypoxemia, ascites, jaundice). CV:
Hypotension, arrhythmias. Endocrine:
Nausea, vomiting, anorexia, abdominal cramps, hepatotoxicity. Hematologic:
Possibility of excessive hypotension with disopyramide.
25 min. Peak:
10 min. Duration:
About 2 h. Distribution:
Unknown if it crosses placenta or into breast milk. Metabolism:
In liver. Elimination:
Primarily in urine. Half-Life:
Assessment & Drug Effects
- Monitor for therapeutic effectiveness: Increased cardiac output, decreased PCWP, relief of symptoms of CHF. Central venous
pressure may be used to assess hypotension and blood volume.
- Monitor BP, heart rate, and respirations and keep physician informed. Rate of administration and duration of therapy are
prescribed according to clinical response and adverse effects.
- Consult physician for guidelines. In general, rate of infusion should be slowed or stopped with excessive drop in BP or
- Monitor infusion site to prevent extravasation.
- Monitor I&O ratio and pattern and daily weights. Improvement in cardiac output enhances diuresis with consequent danger of
hypokalemia and arrhythmias, particularly in digitalized patients.
- Lab tests: Monitor closely platelet counts, liver enzymes, fluid and electrolyte balances, renal function.
- Correct hypokalemia before and during therapy.
- Note: If platelet count falls below 150,000/mm3, report immediately to physician; may indicate thrombocytopenia.
- Allergy alert: IV preparation contains sodium metabisulfite, a reducing agent to which certain susceptible individuals are
allergic. Discontinue immediately if patient shows hypersensitivity reactions.
- Observe patient closely when drug is withdrawn after prolonged therapy; clinical deterioration may occur within hours.