Minocycline Pharmacokinetics (ACUMIN)

This is a Phase IV, multi-center open-label pharmacokinetic trial studying the pharmacokinetics and pharmacodynamics of a single dose of Minocin IV. Up to 67 subjects will be enrolled to obtain 50 evaluable, ICU patients who are already receiving antimicrobial therapy for a known or suspected Gram-negative infection. The entire study duration will be approximately 16 months and each subject participation duration will be approximately 2 days. The study will be conducted at approximately 13 clinical sites. Each subject will receive a single 200 mg dose of Minocin IV infused over approximately 60 minutes. Each subject will have 7 PK samples collected (1 pre-dose, 6 post-dose) at designated time points over a \~48 hour period following the start of the Minocin IV infusion. The primary objectives are: 1) To characterize minocycline PK at the population level in critically-ill adults, with illness known or suspected to be caused by infection with Gram-negative bacteria and 2) To assess patient-level and clinical covariates associated with minocycline pharmacokinetic properties in critically-ill adults, with illness known or suspected to be caused by infection with Gram-negative bacteria. Up to 67 subjects will be enrolled in order to obtain 50 PK evaluable subjects in the study. To be considered PK evaluable, a subject must receive the full infusion of study drug, and is required to have at least 3 PK samples collected in the first 12 hours post dose and at least 1 PK sample collected 24-48 hours post dose. Subjects who are dosed with minocycline but do not meet this PK sampling requirement will still be included in the population PK analysis, but an additional subject will be enrolled as a replacement to meet the goal of having 50 PK evaluable subjects with intensive PK sampling.