Serum creatinine level, complete blood count, and liver enzyme tests should be monitored weekly in this patient. Outpatient parenteral antimicrobial therapy (OPAT) is becoming more common, with some patients receiving therapy for extended periods (≥6 weeks for osteomyelitis). Outpatient monitoring for adverse drug effects and other potential complications resulting from intravenous administration (such as intravenous catheter infection) are part of an OPAT management plan. The plan should be confirmed with all physicians involved in the care of the patient. The monitoring schedule for adverse drug effects depends on the agent being used; the most common antibiotics used for OPAT require weekly laboratory monitoring. For nafcillin, this includes monitoring for bone marrow suppression with a complete blood count (CBC) and liver enzyme tests. Kidney function testing with a serum creatinine level should also be performed weekly, because the dosage of nafcillin may require adjustment if significant deterioration of kidney function occurs or if the patient already has kidney injury and it improves while receiving therapy. Nafcillin may affect potassium levels, but monitoring is not indicated as part of current recommendations. Monitoring of oxacillin and carbapenems is similar to that of nafcillin, and monitoring of other β-lactam antibiotics is similar to that of nafcillin except that liver enzyme testing is not necessary; antipseudomonal penicillins necessitate checking the serum potassium level weekly.