protamine sulfate: clinical use

Prescribing considerations

• Base reversal on the type, route and timing of heparin exposure and objective coagulation assessment.
• Low-molecular-weight heparin anti-Xa activity may not be completely reversible.
• Avoid excess protamine because it has intrinsic anticoagulant activity.
• Administer slowly with facilities available to manage shock or anaphylactoid reactions.
• Safety and efficacy in children are not established; the selected SmPC does not recommend use.

Contraindications and cautions

• The selected SmPC lists no known formal contraindications.
• Use particular caution with previous protamine exposure, protamine-containing insulin treatment, fish allergy, previous cardiopulmonary bypass or coronary procedures, vasectomy or infertility because hypersensitivity risk may be increased.

Monitoring

• Monitor activated partial thromboplastin time or activated clotting time as clinically appropriate.
• Observe blood pressure, heart rate, oxygenation and respiratory status during and after administration.
• Continue surveillance for recurrent anticoagulation or delayed postoperative bleeding after repeated exposure.

Clinical pharmacology

Protamine is a strongly basic heparin antagonist that forms a stable, inactive salt with heparin. Its effect begins within minutes, but protamine may clear sooner than heparin, permitting recurrent anticoagulation.

Formulation and product differences

• The selected product is a clear, colourless solution for intravenous injection supplied in glass ampoules.
• Excipients include sodium chloride, water for injections and pH-adjusting hydrochloric acid and sodium hydroxide.
• Protamine is derived from fish material, which may matter to patients with allergies or ethical or religious concerns.
• The solution is incompatible with certain penicillins and cephalosporins.

Injection

Route: Parenteral

Strengths: 10 mg/mL