DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Protamine (Protamine Sulfate) - Warnings and Precautions



Protamine sulfate can cause severe hypotension, cardiovascular collapse, noncardiogenic pulmonary edema, catastrophic pulmonary vasoconstriction, and pulmonary hypertension.  Risk factors include high dose or overdose, rapid administration (see WARNINGS  and DOSAGE AND ADMINISTRATION ), repeated doses, previous administration of protamine, and current or previous use of protamine-containing drugs (NPH insulin, protamine zinc insulin, and certain beta-blockers).  Allergy to fish, previous vasectomy, and severe left ventricular dysfunction and abnormal preoperative pulmonary hemodynamics also may be risk factors.  In patients with any of these risk factors, the risk to benefit of administration of protamine sulfate should be carefully considered.  Vasopressors and resuscitation equipment should be immediately available in case of a severe reaction to protamine.  Protamine sulfate should not be given when bleeding occurs without prior heparin use.



Hyperheparinemia or bleeding has been reported in experimental animals and in some patients 30 minutes to 18 hours after cardiac surgery (under cardiopulmonary bypass) in spite of complete neutralization of heparin by adequate doses of protamine sulfate at the end of the operation.  It is important to keep the patient under close observation after cardiac surgery.  Additional doses of protamine sulfate should be administered if indicated by coagulation studies, such as the heparin titration test with protamine and the determination of plasma thrombin time.

Too-rapid administration of protamine sulfate can cause severe hypotensive and anaphylactoid reactions (see DOSAGE AND ADMINISTRATION and WARNINGS ).  Facilities to treat shock should be available.



Because of the anticoagulant effect of protamine, it is unwise to give more than 50 mg over a short period unless a larger dose is clearly needed.

Patients with a history of allergy to fish may develop hypersensitivity reactions to protamine, although to date no relationship has been established between allergic reactions to protamine and fish allergy.

Previous exposure to protamine can induce a humoral immune response and predispose susceptible individuals to the development of untoward reactions from the subsequent use of this drug.  Patients exposed to protamine through the use of protamine-containing insulin or during heparin neutralization may experience life-threatening reactions and fatal anaphylaxis upon receiving large doses of protamine intravenously.  Severe reactions to intravenous protamine can occur in the absence of local or systemic allergic reactions to subcutaneous injection of protamine-containing insulin.  Reports of the presence of antiprotamine antibodies in the sera of infertile or vasectomized men suggest that some of these individuals may react to the use of protamine sulfate.

Fatal anaphylaxis has been reported in one patient with no prior history of allergies.

Drug Interactions

Protamine sulfate has been shown to be incompatible with certain antibiotics, including several of the cephalosporins and penicillins (see DOSAGE AND ADMINISTRATION ).

Carcinogenesis, Mutagenesis, Impairment of Fertility

Studies have not been performed to determine potential for carcinogenicity, mutagenicity or impairment of fertility.


Pregnancy Category C —Animal reproduction studies have not been conducted with protamine sulfate.  It is also not known whether protamine sulfate can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.  Protamine sulfate should be given to a pregnant woman only if clearly needed.

Nursing Mothers

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 protamine sulfate is administered to a nursing woman.

Pediatric Use

Safety and effectiveness in children have not been established.

Page last updated: 2014-06-30

-- advertisement -- The American Red Cross
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017