Imipenem (Primaxin) is an intravenous ß-lactam antibiotic discovered by Merck scientists Burton Christensen, William Leanza, and Kenneth Wildonger in 1980. It was the first member of the carbapenem class of antibiotics. Carbapenems are highly resistant to the ß-lactamase enzymes produced by many multiple drug-resistant Gram-negative bacteria, thus play a key role in the treatment of infections not readily treated with other antibiotics.