Milrinone

PRIMACOR

What it isPDE3 inhibitor raising cardiac cAMP; acute decompensated heart failure and bridge to transplant.

Why this oneIt increases contractility while reducing afterload, and works independently of beta receptors, so it still works in beta blockade.

What limits itHypotension and arrhythmia. Renally cleared, so it accumulates; no mortality benefit and worse outcomes with long-term use.

FDA label

FDA dosing	Population	Start	Target	Max
IV inotropic therapy (Indications section not in fetched label; trials in congestive heart failure patients)	Adults	IV loading 50 mcg/kg over 10 min	IV infusion 0.375–0.75 mcg/kg/min, adjusted to hemodynamic/clinical response	IV 1.13 mg/kg/day (0.75 mcg/kg/min)

Renal Reduce infusion rate by CrCl (mL/min/1.73m2): 5 → 0.2; 10 → 0.23; 20 → 0.28; 30 → 0.33; 40 → 0.38; 50 → 0.43 mcg/kg/min

Hepatic Undefined

Loading dose may be given undiluted (or diluted to 10–20 mL); dilute maintenance infusion to 200 mcg/mL in 0.45% NaCl, 0.9% NaCl, or D5W
Use a calibrated electronic infusion device; monitor patients closely
Duration of therapy depends on responsiveness
Inspect visually; do not use if particulate matter or discoloration present

Ventricular arrhythmias 12.1% (ectopy 8.5%, nonsustained VT 2.8%, sustained VT 1%, VF 0.2%); risk with preexisting arrhythmias, hypokalemia, abnormal digoxin levels
Supraventricular arrhythmias 3.8%; rare torsades de pointes (postmarketing)
Hypotension 2.9%; angina/chest pain 1.2%
Headache 2.9%; hypokalemia, tremor, thrombocytopenia
Rare bronchospasm, anaphylactic shock; LFT abnormalities, rash; infusion site reaction

Pregnancy Undefined

Lactation Undefined

NO BOXED WARNINGS

Principal riskHypotension and arrhythmia; it accumulates in renal failure

Direct muscarinic antagonism0 / 4