The side effects of penicillin are bodily responses to penicillin and closely related antibiotics that do not relate directly to its effect on bacteria. A side effect is an effect that is not intended with normal dosing. Some of these reactions are visible and some occur in the body's organs or blood. Penicillins are a widely used group of medications that are effective for the treatment of a wide variety of bacterial infections in human adults and children as well as other species. Some side effects are predictable, of which some are common but not serious, some are uncommon and serious and others are rare. The route of administration of penicillin can have an effect on the development of side effects. An example of this is irritation and inflammation that develops at a peripheral infusion site when penicillin is administered intravenously. In addition, penicillin is available in different forms. There are different penicillin medications (penicillin G benzathine, penicillin G potassium, Penicillin G sodium, penicillin G procaine, and penicillin V) as well as a number of β-lactam antibiotics derived from penicillin (e.g. amoxicillin).
Side effects may only last for a short time and then go away. Side effects can be relieved in some cases with non pharmacological treatment. Some side effects require treatment to correct potentially serious and sometimes fatal reactions to penicillin. Penicillin has not been found to cause birth defects.
