Penicillins are one of a group of antibiotics that kill bacteria or prevent their growth. There are several types of penicillins, each used to treat different kinds of infections, such as skin, dental, ear, respiratory tract, urinary tract, and other bacterial infections. These drugs will not work for colds, flu, and other infections caused by viruses.

Examples of penicillins are penicillin V (Beepen-VK, Pen-Vee K, V-cillin K, Veetids) and amoxicillin (Amoxil, Polymox, Trimox, Wymox). Penicillins are sometimes combined with other ingredients called beta-lactamase inhibitors, which protect the penicillin from bacterial enzymes that may destroy it before it can do its work.

Penicillins are available only with a physician's prescription and are sold in capsule, tablet (regular and chewable), liquid, and injectable forms. The recommended dosage depends on the type of penicillin, the strength of the medication, and the medical problem for which it is being taken.

Penicillins must...