Protamine sulfate is used to reverse the effects of which substance?

Protamine sulfate is specifically designed as an antidote to reverse the anticoagulant effects of heparin, which is a medication commonly used to prevent blood clots during various medical procedures. Heparin works by inhibiting the activity of clotting factors in the blood; however, in situations where excessive anticoagulation occurs, protamine sulfate can neutralize its effects.

Upon administration, protamine sulfate binds to heparin, forming a stable complex that effectively inactivates it, thereby restoring normal clotting function. This reversal is critical in surgical settings where blood loss needs to be managed and normal hemostasis must be quickly restored.

The other substances listed – epinephrine, narcotics, and metabolic acidosis – do not have a direct relationship with protamine sulfate. Epinephrine is used for its vasoconstrictive properties and to treat anaphylaxis, narcotics are managed with antagonists like naloxone, and metabolic acidosis may involve different treatment approaches such as bicarbonate administration or addressing the underlying cause, rather than the use of protamine sulfate. Therefore, protamine sulfate is exclusively associated with reversing the effects of heparin.