Therapeutic drug monitoring of linezolid in a case of pulmonary nocardiosis: a case report

This clinical case discusses a man between 60 and 70 years old with lung adenocarcinoma who developed a <i>Nocardia cyriacigeorgica</i> infection. Because it is an intracellular bacterium, we need to start antibiotic treatment and maintain for a year. For initial therapy, sulfamethoxazole/trimethoprim (SMX/TMP) is the preferred antibiotic, but it can cause side effects, such as liver damage. Linezolid is another valid alternative.Pharmacokinetic monitoring of linezolid was essential in managing the patient because the drug can cause significant side effects like myelosuppression. The pharmacist tracked serum levels over 7 months, allowing for dose adjustments that minimised toxicity and ensured effective treatment. Elevated linezolid levels were linked to thrombocytopenia, prompting timely dosage modifications that improved the patient's haemoglobin and platelet counts.This case highlights the critical role of pharmacokinetic monitoring in optimising linezolid therapy. The pharmacist's involvement enhanced treatment efficacy, but also safeguarded the patient from serious adverse effects, demonstrating the importance of collaborative healthcare.