What happens to tigecycline levels when probenecid is given?
Probenecid can increase tigecycline exposure by inhibiting specific transporters involved in tigecycline’s disposition. In clinical pharmacokinetic studies described in the tigecycline label, coadministration of probenecid resulted in higher tigecycline plasma concentrations than tigecycline alone, indicating that probenecid slows tigecycline clearance through transporter inhibition [1].
Which clearance mechanisms does this interaction affect?
The interaction is consistent with transporter-mediated elimination. Probenecid is known to inhibit renal tubular secretion via transporters such as OATs, and tigecycline’s disposition involves transporter pathways as well. Blocking these pathways reduces the rate at which tigecycline is removed from the body, shifting pharmacokinetics toward higher systemic exposure [1].
Does probenecid change tigecycline distribution or only clearance?
The observed effect is primarily on systemic exposure (concentration), which tracks with a change in clearance rather than a direct, immediate change in distribution. In other words, the key pharmacokinetic signal reported is that tigecycline levels are higher when probenecid is coadministered [1].
Is this interaction clinically meaningful for dosing?
The evidence summarized in the prescribing information points to a pharmacokinetic interaction, but the label does not provide a specific dosing adjustment for tigecycline solely because of probenecid. If probenecid is used concurrently, clinicians typically monitor for tolerability and overall treatment response, especially in patients with additional factors that raise tigecycline exposure (such as impaired organ function) [1].
Are there other drug interactions that could similarly raise tigecycline exposure?
Yes. Tigecycline has multiple transporter-related interaction risks. Other inhibitors of the relevant efflux/uptake transport pathways can also increase tigecycline concentrations, so the overall medication profile matters when assessing exposure risk [1].
Sources
- https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=021821