1 An older antibiotic, but still in use, and effective where you might be allergic to the penicillins. However, it may cause various types of stomach upset, and so is usually kept in reserve.  Clindamycin is the 500lb. gorilla of tooth abscess antibiotics used in dentistry.
A communicable disease is an illness transmitted through contact with microorganisms. People, animals, food, surfaces, and air can all be carriers of the microorganisms that pass infectious illnesses from one host to the next.
contagious disease (also called a communicable disease) is an infectious disease that is capable of being transmitted from one person or species to another. Apparently they are the same. Not true. Contagious diseases are most often communicable enough to warrant quarantine, whereas communicable diseases (such as the flu) are not.