title: Use of dapsone in the treatment of Pneumocystis carinii pneumonia in a foal.
abstract: A 6-month-old male Quarter Horse was evaluated for chronic respiratory tract disease. Diagnostic investigations revealed pulmonary inflammation; Pneumocystis carinii was detected within macrophages. Lymphocyte subpopulation phenotyping and immunoglobulin concentration analysis were performed and results suggested immune suppression. Trimethoprim-sulfamethoxazole administration was initiated; the colt was discharged but was reexamined 8 days later because of profuse diarrhea and endotoxemia. Bacterial culture of feces recovered Salmonella spp resistant to trimethoprim-sulfamethoxazole, and a diagnosis of antimicrobial-associated colitis was made. Bilateral fibrinous hypopyon developed and was treated with topical medication and intracameral injections of human recombinant tissue plasminogen activator. Dapsone (3 mg/kg [1.4 mg/lb], PO, q 24 h; dose extrapolated from human data) was administered for treatment of P carinii pneumonia (56-day treatment period). The colt recovered from the pneumonia and diarrhea. Dapsone may be a useful adjunct to traditional treatment for P carinii pneumonia in horses or as a sole medication for horses that cannot tolerate other treatments.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506-5606, USA.
authors.forename: Stuart C
authors.initials: SC
authors.lastname: Clark-Price
authors.forename: Judy H
authors.initials: JH
authors.lastname: Cox
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Bartoe
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Davis
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000009:adverse effects / Q000627:therapeutic use*; D003622:Dapsone / Q000494:pharmacology / Q000627:therapeutic use*; D003967:Diarrhea / Q000150:complications / Q000188:drug therapy / Q000662:veterinary; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D008297:Male; D045363:Pneumocystis carinii / Q000187:drug effects / Q000302:isolation & purification; D011020:Pneumonia, Pneumocystis / Q000150:complications / Q000188:drug therapy / Q000662:veterinary*; D016896:Treatment Outcome; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D000890:Anti-Infective Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D003622:Dapsone