What is the drug of choice to reverse the effects of anticoagulant therapy?

Protamine sulfate is the drug of choice to reverse the effects of anticoagulant therapy, specifically when dealing with heparin overdose or uncontrolled bleeding due to heparin. It acts as an antidote by binding to heparin and neutralizing its anticoagulant effects. When administered intravenously, it can rapidly reduce the effect of heparin, making it crucial in emergency situations where a patient may require rapid coagulation.

In contrast, while calcium gluconate is important for addressing hypocalcemia and can be used in certain scenarios such as managing potassium levels or in some cardiac conditions, it does not serve to reverse the effects of anticoagulants. Low-molecular-weight heparin, on the other hand, is a type of anticoagulant and therefore cannot be used to reverse anticoagulation. Narcan (naloxone) is an opioid antagonist that is used to reverse the effects of opioid overdose, and it is not related to anticoagulation management. Thus, protamine sulfate stands out as the most effective and appropriate choice for reversing anticoagulation effects in the context described.