Protamine sulfate

Since it's earliest discovery in salmon rine sperm heads in the late 1800's to its formal introduction via US FDA approval in 1939, protamine sulfate has occupied an important therapeutic niche as perhaps the only viable option for reversing the anticoagulant effect of heparin use for over 77 years . Subsequently, because most invasive surgical procedures involve the routine use of heparin to prevent potentially surgery-complicating blood clotting, most cases of major bleeding in these frequent procedures are managed with the use of protamine sulfate . The agent elicits this heparin reversal predominantly via the formation of an inactive complex between the anionic nature of heparin and its own cationic state .

Despite the relative importance of protamine sulfate's medical indication, the medication can notoriously cause a variety of potentially rare but genuinely severe adverse effects that include systemic hypotension, pulmonary hypertension, liver and kidney tissue damage, and anaphylactic reaction, amongst others . As a consequence, whenever protamine sulfate use is clinically considered, careful consideration must be given as to whether the use of the agent could decrease the safety of the procedure or worsen the recovery of a patient after the procedure .

Regardless, protamine sulfate continues to see contemporary use given its genuine effectiveness in reversing heparin effects. Although current up to date reviews and studies continue to search for new therapeutic alternatives to protamine sulfate, most substitutes possess similar and unacceptable adverse effects . Of the few agents that may be considered potentially successful alternatives - including idarucizumab for dabigatran reversal - their cost of procurement and potential range in reversing all parenteral anticoagulants are sometimes considered high and limited, respectively .

Protamine sulfate is indicated for counteracting or reversing the anticoagulant effect of heparin as necessary . Such reversal may, for example, be required often before surgery; after renal hemodialysis; post open heart surgery; whenever excessive bleeding results from heparin use; and/or for the treatment of heparin overdosage, among other similar or related circumstances .