The Use of Bactrim in the Periodic Paralyses

Submitted by deb on Sat, 07/25/2015 – 18:54

The antibiotic Bactrim is well-known to produce muscle weakness, even paralysis in patients with Hypokalemic Periodic Paralysis. It is contraindicated in patients with Anderson-Tawil Syndrome because of its propensity to produce cardiac arrhythmia, but many clinicians do not realize that it also produces hyperkalemia in a majority of patients who take it, which in a patient with healthy kidneys and no propensity to hyperkalemia is usually not a problem, but in patients who have Hyperkalemic Periodic Paralysis or Paramyotonia Congenita can lead to a rapid and dangerous escalation of symptoms. 

The following review article from the Canadian Medical Association Journal outlines the effects of Bactrim on potassium levels, as well as potential neurological and blood dycrasias.

 Considerations when prescribing trimethoprim–sulfamethoxazole