Carbapenems have a number of adverse effects that can be classified by the affected system. Carbapenems can cause hypersensitivity reactions. These reactions will often present as skin rashes, urticaria, or even Stevens-Johnson syndrome in severe cases. Gastrointestinal side effects include nausea, vomiting, and abnormal liver-function tests and transaminases. From a bone-marrow perspective, marrow suppression and a positive Coombs test can result. Renal dysfunction can result from imipenem use and all beta-lactam antibacterial agents (including imipenem) require dosage adjustment in the setting of renal insufficiency and failure because of their renal excretion. Neurologically, imipenem can cause myoclonus and seizures. Seizures are a fairly common complication and result from a lowering of the seizure threshold in susceptible patients. Fortunately, this complication is not nearly as common with the use of meropenem. Seizures also occur in the setting of new-onset renal dysfunction if the carbapenem dose is not adjusted.