Protamine sulfate is indicated to neutralize the anticoagulant effect of heparin. It is used before surgery, after renal dialysis, following open-heart surgery, in cases of excessive bleeding, and in accidental heparin overdose.

When used as an antidote to heparin, protamine sulfate acts as a strongly basic protein that binds with the acidic heparin to form a stable and inactive complex. This complex neutralizes the anticoagulant effect of heparin. Protamine sulfate therefore effectively reverses the action of heparin and is useful in treating hemorrhage caused by excessive heparin or low-molecular-weight heparin. It is also commonly used to neutralize heparin before surgery and during procedures such as hemodialysis or cardiac surgery.

Protamine sulfate should be administered by slow intravenous injection over approximately 10 minutes. No more than 50 mg should be given in any single dose.

The dose depends on the type and amount of heparin to be neutralized, the route of administration, and the time elapsed since administration. In cases where heparin is given continuously, the required dose should be guided by coagulation tests or protamine neutralization tests.

In excessive amounts, protamine itself may act as an anticoagulant.

Neutralisation of Unfractionated (UF) Heparin:

• 1 mg protamine sulfate usually neutralizes at least 100 IU of mucous heparin or 80 IU of lung heparin. The dose should be reduced if more than 15 minutes have passed since administration
• If 30–60 minutes have elapsed after IV heparin injection, 0.5–0.75 mg protamine per 100 IU mucous heparin is recommended
• If 2 hours or more have elapsed, 0.25–0.375 mg per 100 IU mucous heparin is suggested
• If heparin is being given by continuous infusion, stop the infusion and administer 25–50 mg protamine slowly IV
• If given subcutaneously, administer 1 mg protamine per 100 IU heparin (half dose IV, remainder over 8–16 hours)

Neutralisation of Low Molecular Weight (LMW) Heparins:

• About 1 mg protamine per 100 anti-Xa units is recommended (manufacturer guidelines should be followed)
• Anti-Xa activity may not be fully reversed and may persist for up to 24 hours
• For LMWH given within 8 hours, use the full protamine dose; if after 8 hours, use half the dose
• Continuous infusion may be required for subcutaneous LMWH neutralization
• Careful monitoring is essential, and additional doses may be needed

Elderly: No adjustment in dose is generally required.

Children: Safety and effectiveness have not been established; not recommended.

Blood and lymphatic system disorders: Anticoagulant effect may occur when protamine is given in excess beyond the amount required to neutralize heparin.

Immune system disorders: Hypersensitivity reactions, including angioedema, anaphylactoid reactions, and fatal anaphylaxis, have been reported.

Cardiac disorders: Bradycardia

Vascular disorders: Sudden drop in blood pressure, pulmonary and systemic hypertension, transient flushing with warmth, and severe pulmonary vasoconstriction that may lead to cardiovascular collapse

Respiratory, thoracic, and mediastinal disorders: Dyspnea; rare cases of noncardiogenic pulmonary edema with prolonged hypotension, associated with significant morbidity and mortality

Gastrointestinal disorders: Nausea and vomiting

Musculoskeletal and connective tissue disorders: Back pain

General disorders and administration site conditions: Lassitude (weakness or fatigue)General disorders and administration site conditions: Lassitude (weakness or fatigue)

As with most medications, Protamine Sulfate should be used during pregnancy only if clearly necessary. Caution is advised when used during breastfeeding.

Too rapid administration of protamine sulfate can result in severe hypotension and anaphylactoid reactions. Appropriate facilities for resuscitation and management of shock should always be available.

Protamine sulfate is not effective in reversing the effects of oral anticoagulants. Caution is required in patients who are at increased risk of hypersensitivity to protamine. These include patients with a history of coronary angioplasty or cardiopulmonary bypass, diabetic patients treated with protamine-containing insulin, individuals with fish allergy, and men who have undergone vasectomy or are infertile and may have developed antibodies to protamine.

Patients undergoing prolonged procedures with repeated doses of protamine should be carefully monitored for coagulation status. Rebound bleeding may occur up to 18 hours after surgery, which may require additional doses of protamine.

Anticoagulants, Parenteral anticoagulants

Store between 15°C and 25°C.