Final answer:
Heparin is a drug that can be used to prolong blood clotting time. Diphenhydramine (Benadryl) and Lidocaine do not have anticoagulant properties.
Step-by-step explanation:
There are drugs that can be used to prolong blood clotting time, and these include Heparin. Heparin is a short-acting anticoagulant that opposes prothrombin, which helps prevent the formation of blood clots. It is often administered therapeutically to surgical patients at risk for blood clots. On the other hand, Diphenhydramine (Benadryl) and Lidocaine do not have anticoagulant properties and do not prolong blood clotting time.