Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Phosphodiesterase-3 inhibitor (inotrope/vasodilator) Pregnancy: Section 4.6: 'There is no evidence of animal teratogenicity with oral therapy. Reproduction studies performed in rats at doses up to 300 mg/kg/day and 100 mg/kg/day have revealed reductions in maternal food consumption, maternal body weight gain and in pup weight at weaning and sexual maturity when enoximone was administered throughout pregnancy and lactation. Sexual behaviour and reproductive capability were unaltered by enoximone treatment. There are no adequate data from the use of enoximone in pregnant women. Perfan Injection should not be used during pregnancy unless clearly necessary. It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Perfan Injection is administered to a nursing mother.'

Enoximone

Brand names: Perfan

Enoximone is a phosphodiesterase type 3 inhibitor with positive inotropic and vasodilator properties, used for short-term support in severe congestive heart failure.

Adult dose

Dose: Short-term treatment of congestive heart failure, typically where cardiac output is reduced and filling pressures increased, in patients who require intravenous therapy and can be closely monitored. Initial therapy: 0.5 - 1.0 mg/kg as a slow intravenous injection (not faster than 12.5 mg/min); further doses of 0.5 mg/kg may be given similarly every 30 minutes until a satisfactory response is achieved or a total initial dose of 3.0 mg/kg is reached. Alternatively, initiate as an infusion at 90 µg/kg/minute over 10 - 30 minutes until the required haemodynamic response is achieved. Maintenance: the initial dose (not more than 3.0 mg/kg) may be repeated as required every 3 - 6 hours and adjusted to response; alternatively a continuous or intermittent infusion at 5 to 20 µg/kg/minute.
Route: Intravenous (slow injection or continuous infusion, after dilution)
Frequency: Maintenance: initial dose repeated as required every 3 - 6 hours, or continuous/intermittent infusion
Max: 24.0 mg/kg/day - SPC: 'The total dose over 24 hours should not normally exceed 24.0 mg/kg.' Total initial dose not more than 3.0 mg/kg.
Strength (SPC section 2): enoximone solution 5 mg/ml in 20 ml ampoules (100 mg/20 ml). DILUTION (section 4.2): pH is approximately 12.0; must be diluted with an equal volume of 0.9% sodium chloride injection or water for injections before administration. Do not use more dilute solutions or other diluents, particularly dextrose injection, as crystal formation may occur. Use only plastic containers or syringes - crystal formation has been observed within approximately 1 hour when diluted in glass. Take precautions to avoid venous extravasation. The initial haemodynamic response determines the subsequent rate and duration of treatment; duration depends on the patient's continued positive and beneficial response; sustained effects have been observed in patients treated for up to 48 hours. SPC: the regimen produces in the majority of patients a 30% or greater increase in cardiac output and/or decreases in pulmonary capillary wedge pressure of about 30% and right atrial pressure of about 40%. Use cautiously when heart failure is associated with hypertrophic cardiomyopathy, stenotic or obstructive valvular disease or other outlet obstruction (section 4.4). Contains 10.4 vol % ethanol and propylene glycol (section 4.4). Use in children: safety and effectiveness in children have not been established; there is no experience in children (section 4.2).

Dose adjustments

Renal

SPC 4.2: in patients with renal impairment the dosage or dosage frequency may need to be reduced. Renal function should be assessed during therapy (section 4.4).

Hepatic

SPC 4.2 gives no hepatic dose adjustment. SPC 4.4: monitor for changes in hepatic enzyme levels; if clinically significant increases in hepatic enzymes occur following intravenous administration, therapy should be discontinued.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via MHRA Products — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients (section 4.3)

Side effects

  • Common (section 4.8): hypotension, insomnia, headache, platelet count reduction (without clinical symptoms), rise in transaminases and bilirubin
  • Uncommon (section 4.8): ventricular tachycardia and supraventricular arrhythmia, dizziness, vomiting, nausea, diarrhoea, slight rise in blood glucose and alkaline phosphatase, slight rise in leukocytes, slight decrease in haematocrit and haemoglobin, slight rise in urea, creatinine or uric acid
  • Rare (section 4.8): (thrombo-)phlebitis at the site of injection, fever, chills, urinary retention, oliguria, fluid retention, irritation, muscle pain in extremities
  • Very rare (section 4.8): ventricular fibrillation, particularly at doses of > 3 mg/kg BW
  • Severe supraventricular and ventricular arrhythmias may require immediate discontinuation and antiarrhythmic therapy (section 4.4)
  • Severe gastrointestinal side effects may be managed by reducing dosage or temporarily interrupting administration (section 4.4)
  • Propylene glycol at high doses or with prolonged use: hyperosmolality, lactic acidosis, renal dysfunction, cardiotoxicity, CNS disorders, respiratory depression, liver dysfunction, haemolytic reaction (section 4.4)

Interactions

  • No interaction studies have been performed (section 4.5)
  • No untoward interactions were observed in patients also receiving diuretics, digitalis glycosides, potassium supplements, antiarrhythmics, vasodilators, anticoagulants, analgesics, sedatives or positive inotropic agents (dobutamine, dopamine) (section 4.5)
  • Digitalis - abnormal serum potassium (e.g. from excessive diuresis) may predispose to arrhythmias, especially in patients on digitalis (section 4.4)
  • Diuretics - improvement in cardiac output with associated diuresis may require a reduction in the dose of diuretic drugs (section 4.4)

Monitoring

  • Blood pressure and heart rate closely during intravenous administration; reduce the rate or stop if symptomatic decreases in blood pressure (section 4.4)
  • Close observation for arrhythmias - patients with severe congestive heart failure are particularly vulnerable (section 4.4)
  • Fluid and electrolyte status and renal function during therapy; serum potassium carefully, correcting abnormalities before or during therapy (section 4.4)
  • Platelet counts before and during therapy (sections 4.4, 4.5)
  • Hepatic enzyme levels (sections 4.4, 4.5)
  • Haemodynamic response (cardiac output, pulmonary capillary wedge pressure, right atrial pressure) guides the rate and duration of treatment (section 4.2)

Clinical monograph

How it works

By inhibiting phosphodiesterase type 3 it raises intracellular cyclic AMP, increasing myocardial contractility and causing peripheral vasodilatation (inodilator effect).

Prescribing in practice

  • It is for short-term use under specialist supervision and can cause hypotension and arrhythmias, requiring continuous haemodynamic and cardiac monitoring.
  • Reserve for severe heart failure where other treatments are inadequate, given the lack of benefit and potential harm with prolonged inotrope use.
  • Use with caution in hypovolaemia and in outflow-tract obstruction such as significant aortic or pulmonary stenosis.

Monitoring

Monitor blood pressure, cardiac rhythm and haemodynamic status continuously during administration in a monitored setting.

Counselling the patient

  • This is a hospital infusion given under close monitoring.
  • The care team should watch blood pressure and cardiac rhythm closely.
  • It is intended only for short-term circulatory support.

Evidence & guidelines

Phosphodiesterase inhibitors improve haemodynamics in acute heart failure but long-term inotrope use is associated with increased mortality, so their role is limited to short-term support.

Reference: ESC acute HF guidelines; AAGBI ICU; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways