AIMS: Co-trimoxazole maintains a well-established role in the treatment of Pneumocystis jirovecii and Toxoplasma gondii, as well as urinary tract infections. Observational studies report hyperkalaemia to be associated with co-trimoxazole, which may stem from an amiloride-like potassium-sparing effect. The current study investigated changes in serum potassium in patients without acute infections, and the influence of concomitant antikaliuretic drugs on this effect. METHODS: A post hoc analysis was carried out of a randomized controlled trial in patients with interstitial lung disease who were assigned to placebo or 960 mg co-trimoxazole twice daily. Serum potassium and creatinine were measured at baseline, 6 weeks, and 6, 9 and 12 months. The primary outcome was the difference in mean serum potassium concentrations between co-trimoxazole and placebo at 6 weeks. RESULTS: Mean serum potassium levels were similar at baseline: 4.24 (± 0.44) mmol l-1 in the 87 co-trimoxazole group participants and 4.25 (± 0.39) mmol l-1 in the 83 control participants. Co-trimoxazole significantly increased mean serum potassium levels at 6 weeks, with a difference between means compared with placebo of 0.21 mmol l-1 [95% confidence interval (CI) 0.09, 0.34; P = 0.001). This significant increase in serum potassium was detectable even after exclusion of patients on antikaliuretic drugs, with a difference between means for co-trimoxazole compared with placebo of 0.23 mmol l-1 (95% CI 0.09, 0.38; P = 0.002). There were 5/87 (5.7%) patients on co-trimoxazole whose serum potassium concentrations reached ≥5.5 mmol l-1 during the study period. CONCLUSIONS: Co-trimoxazole significantly increases serum potassium concentration, even in participants not using antikaliuretic drugs. While the magnitude of increase was often minor, a small proportion in our outpatient cohort developed hyperkalaemia of clinical importance.
AIMS: Co-trimoxazole maintains a well-established role in the treatment of Pneumocystis jirovecii and Toxoplasma gondii, as well as urinary tract infections. Observational studies report hyperkalaemia to be associated with co-trimoxazole, which may stem from an amiloride-like potassium-sparing effect. The current study investigated changes in serum potassium in patients without acute infections, and the influence of concomitant antikaliuretic drugs on this effect. METHODS: A post hoc analysis was carried out of a randomized controlled trial in patients with interstitial lung disease who were assigned to placebo or 960 mg co-trimoxazole twice daily. Serum potassium and creatinine were measured at baseline, 6 weeks, and 6, 9 and 12 months. The primary outcome was the difference in mean serum potassium concentrations between co-trimoxazole and placebo at 6 weeks. RESULTS: Mean serum potassium levels were similar at baseline: 4.24 (± 0.44) mmol l-1 in the 87 co-trimoxazole group participants and 4.25 (± 0.39) mmol l-1 in the 83 control participants. Co-trimoxazole significantly increased mean serum potassium levels at 6 weeks, with a difference between means compared with placebo of 0.21 mmol l-1 [95% confidence interval (CI) 0.09, 0.34; P = 0.001). This significant increase in serum potassium was detectable even after exclusion of patients on antikaliuretic drugs, with a difference between means for co-trimoxazole compared with placebo of 0.23 mmol l-1 (95% CI 0.09, 0.38; P = 0.002). There were 5/87 (5.7%) patients on co-trimoxazole whose serum potassium concentrations reached ≥5.5 mmol l-1 during the study period. CONCLUSIONS: Co-trimoxazole significantly increases serum potassium concentration, even in participants not using antikaliuretic drugs. While the magnitude of increase was often minor, a small proportion in our outpatient cohort developed hyperkalaemia of clinical importance.
Authors: Tony Antoniou; Simon Hollands; Erin M Macdonald; Tara Gomes; Muhammad M Mamdani; David N Juurlink Journal: CMAJ Date: 2015-02-02 Impact factor: 8.262
Authors: Matthew A Weir; David N Juurlink; Tara Gomes; Muhammad Mamdani; Daniel G Hackam; Arsh K Jain; Amit X Garg Journal: Clin J Am Soc Nephrol Date: 2010-07-01 Impact factor: 8.237
Authors: Stephen Ph Alexander; Doriano Fabbro; Eamonn Kelly; Neil Marrion; John A Peters; Helen E Benson; Elena Faccenda; Adam J Pawson; Joanna L Sharman; Christopher Southan; Jamie A Davies Journal: Br J Pharmacol Date: 2015-12 Impact factor: 8.739
Authors: Elizabeth Crellin; Kathryn E Mansfield; Clémence Leyrat; Dorothea Nitsch; Ian J Douglas; Adrian Root; Elizabeth Williamson; Liam Smeeth; Laurie A Tomlinson Journal: BMJ Date: 2018-02-09