Penicillin VK (generic: penicillin V potassium) is a prescription medication used to treat mild to moderate infections of the ears, nose, throat, and skin. It is also used to treat scarlet fever and to prevent rheumatic fever. Penicillin VK belongs to a group of drugs called antibiotics, which stop the growth of bacteria in the body.

This medication comes in tablet and oral (by mouth) solution forms and may be taken 2 to 4 times a day, with or without food.

Common side effects of Penicillin VK include nausea, vomiting, upset stomach, diarrhea, and black hairy tongue.