Protamine sulfate

Administration

• Type: Antidote
• Dosage Forms:
• Routes of Administration: IV
• Common Trade Names:

Adult Dosing

• Major bleeding due to unfractionated heparin:
  • 1 mg IV for every 100 units of heparin infused in past 3h
  • Do not infuse faster than 50mg/10min
  • If it has been >30min since last heparin injection, 0.5mg may be sufficient
  • Give slowly over 1-3min; do not exceed 50mg in any 10 minute period (anaphylaxis risk)
  • Because half-life is short (7 min) may require second treatment
• Major bleeding due to low-molecular-weight heparin:
  • Protamine is less effective for bleeding from LMWH than it is with heparin-induced bleeds
  • Enoxaparin: 1 mg IV for every 1 mg enoxaparin administered in past 8h
  • Dalteparin: 1 mg IV for every 100 anti-Xa international units of dalteparin

Pediatric Dosing

Safety/Efficacy not well established in pediatrics, but unofficial suggested dosing similar to adult dosing

Special Populations

• Pregnancy Rating: C
• Lactation risk: Infant risk cannot be ruled out
• Renal dosing: no adjustment
• Hepatic dosing: no adjustment

Contraindications

• Allergy to class/drug

Adverse Reactions

Serious

• Anaphylaxis(0.2% of patients), anaphylactoid reaction
• Circulatory collapse, capillary leak, bradyarrhythmia, hypotension
• Pulmonary edema

Common

• Flushing
• Dyspnea
• Nausea/vomiting

Pharmacology

• Half-life:
  • ~7 minutes
• Metabolism:
• Excretion:

Mechanism of Action

• Weak anticoagulant, heparin antagonist

See Also

• Anticoagulant reversal, Unfractionated heparin reversal
• Unfractionated heparin, Low molecular weight heparin

References

• Protamine sulfate: Drug information. UpToDate. www.uptodate.com. Accessed April 2, 2019.