Trimethoprim, Creatinine and Creatinine-Based Equations

Abstract

Co-trimoxazole is a frequently prescribed antibiotic worldwide. It is composed of both trimethoprim and sulfamethoxazol (Sfx) and is used in the treatment and prophylaxis of urinary tract and Pneumocystis jirovecii infections. The Sfx component appears to be nephrotoxic at high doses or doses inappropriately adjusted for glomerular filtration rate (GFR). The trimethoprim component, even at recommended doses, inhibits tubular creatinine secretion, leading to a rapid but ultimately reversible increase in serum creatinine independent of any changes in GFR. This translates into a falsely low estimated GFR when creatinine-based equations are used. This review focuses on evidence of the differential effects of trimethoprim and Sfx on serum creatinine concentrations and GFR and their relevance to clinical practice, with particular attention to kidney transplantation.

Taking the challenge: A protocolized approach to optimize Pneumocystis pneumonia prophylaxis in renal transplant recipients

“…This rise is likely due to inhibition of tubular Cr secretion by trimethoprim which can result in reversible increases in SeCr higher than 35% in patients with pre-existing renal impairment (11) and, therefore, likely to recur on TMP-SMX rechallenge. We did not observe similar rates of SeCr rise in our cohort, possibly due to the intermittent dose routinely used as it is likely that this ADR is dose-related (12). Although reversible, increases in SeCr in RTRs may elicit concerns of acute rejection and therefore, treating physicians should be aware of this phenomenon.…”

A randomized controlled study of trimethoprim‐sulfamethoxazole versus norfloxacin for the prevention of infection in cirrhotic patients

“…Although two episodes of renal failure developed during T‐S administration, we do not think either case was related to T‐S. T‐S is rarely associated with renal complications and is known to cause an increase in serum creatinine . All adverse events resolved with drug cessation.…”

The Problem of Renal Function Monitoring in Patients Treated With the Novel Antiretroviral Drugs

“…In these conditions, tubular secretion may be higher than 35% of total excretion. 24 In addition to the evaluation of glomerular fi ltration, the tubular function needs to be carefully monitored. Simple tests may help manage this issue.…”