title: Trimethoprim/sulfamethoxazole and metabolic acidosis in HIV-infected patients.
abstract: OBJECTIVE
  To describe a retrospective study of six HIV-positive individuals with compensated metabolic acidosis while receiving intravenous trimethoprim/sulfamethoxazole (TMP/SMX).
  
  
  METHODS
  Six HIV-infected patients were treated for Pneumocystis carinii pneumonia (PCP) with high-dose intravenous TMP/SMX. In spite of a favorable clinical and radiologic course, all six patients developed compensated metabolic acidosis 3-5 days after the start of treatment. This potential complication of TMP/SMX use was successfully managed with conservative treatment (cessation of therapy with or without additional administration of intravenous bicarbonate).
  
  
  CONCLUSIONS
  TMP/SMX is first-line therapy for PCP in HIV-positive individuals, despite a high frequency of toxic effects in these patients. In addition to the cases reported here, only two other reports of metabolic acidosis secondary to TMP/SMX use in HIV-infected patients have been published in the literature. The precise mechanism of this untoward effect is not fully understood, although renal tubular acidosis induced by TMP/SMX could be implicated.
  
  
  CONCLUSIONS
  TMP/SMX toxicity should be considered in the differential diagnosis of HIV-infected patients with acute metabolic acidosis. Metabolic acidosis can be expected to resolve shortly after discontinuation of the drug.
authors.affiliation: Section of Internal Medicine, Hospital of Laredo, Cantabria, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Porras
authors.forename: J N
authors.initials: JN
authors.lastname: Lecumberri
authors.forename: J L
authors.initials: JL
authors.lastname: Castrillón
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000188:drug therapy*; D000138:Acidosis / Q000139:chemically induced*; D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D011020:Pneumonia, Pneumocystis / Q000188:drug therapy*; D013420:Sulfamethoxazole / Q000008:administration & dosage / Q000009:adverse effects*; D014295:Trimethoprim / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D000890:Anti-Infective Agents; D014295:Trimethoprim; D013420:Sulfamethoxazole