Vancomycin is generally the first-line antibiotic for osteomyelitis given the prevalence of methicillin-resistant Staphylococcus aureus (MRSA). If there is no risk for MRSA, piperacillin-tazobactam is usually first line. Valproic acid is primarily a drug used to treat epilepsy/seizure disorder. Valsartan is an angiotensin II receptor blocker (ARB). This class can be recognized by the –sartan suffix. Vardenafil is a PDE5 inhibitor used to treat erectile dysfunction. PDE5 inhibitors can be recognized by the –afil suffix.