LETTER
Comparison of Oral Agents for Treatment of Pneumocystis carinii Pneumonia
Mark A. Perazella, MD
1 March 1997 | Volume 126 Issue 5 | Page 407
TO THE EDITOR:
Safrin and colleagues [1] provide a useful comparison of the efficacy and tolerability of three oral antibiotic regimens (trimethoprim-sulfamethoxazole, dapsone-trimethoprim, and clindamycin-primaquine) used to treat Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome (AIDS). Rash, nausea and vomiting, myelosuppression, and hepatotoxicity accounted for most of the toxic reactions associated with these regimens. Surprisingly, hyperkalemia occurred in only one of their patients, who was treated with either trimethoprim-sulfamethoxazole or dapsone-trimethoprim. This lack of hyperkalemia makes the results of this study clearly different from the results of previous studies done in patients with AIDS who received trimethoprim-containing regimens [2, 3]; in these studies, hyperkalemia developed in 20% to 53% of patients.
In the study by Safrin and colleagues, the absence of hyperkalemia in patients treated with a trimethoprim-containing regimen may be related to the dosage of trimethoprim used. Trimethoprim was prescribed at a lower dose (10 to 20 mg/kg of body weight per day) than was used in other studies (20 mg/kg per day) [2, 3]. However, because one study showed that standard-dose trimethoprim-sulfamethoxazole (320 mg/d) was associated with hyperkalemia in 62.5% of hospitalized patients who did not have AIDS [4], it is unlikely that the lower dose completely explains the absence of hyperkalemia. Alternatively, the patients in the study by Safrin and colleagues [1] may have had significantly lower serum potassium concentrations at baseline. It is possible that these concentrations increased significantly with trimethoprim relative to baseline but did not reach a level consistent with hyperkalemia. Therefore, it would be of interest to know 1) the baseline and follow-up serum or plasma potassium concentrations in these patients and 2) the potassium concentration that was used to define hyperkalemia.
|
Author and Article Information
|
|---|
Yale University School of Medicine, New Haven, CT 06520
1. Safrin S, Finkelstein DM, Feinberg J, Frame P, Simpson G, Wu A, et al. Comparison of three regimens for treatment of mild to moderate Pneumocystis carinii pneumonia in patients with AIDS. A double-blind, randomized trial of oral trimethoprim-sulfamethoxazole, dapsone-trimethoprim, and clindamycin-primaquine. Ann Intern Med. 1996; 124:792-802.
2. Medina I, Mills J, Leoung G, Hopewell PC, Lee B, Modin G, et al. Oral therapy for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome. A controlled trial of trimethoprim-sulfamethoxazole versus trimethoprim-dapsone. N Engl J Med. 1990; 323:776-82.
3. Velazquez H, Perazella MA, Wright FS, Ellison DH. Renal mechanism of trimethoprim-induced hyperkalemia. Ann Intern Med. 1993; 119:296-301.
4. Alappan R, Perazella MA, Buller GK. Hyperkalemia in hospitalized patients treated with trimethoprim-sulfamethoxazole. Ann Intern Med. 1996; 124:316-20.
About Letters
The Editors welcome submissions for possible publication in the Letters section. Authors of letters should:
•Include no more than 300 words of text, three authors, and five references
•Type with double-spacing
•Send three copies of the letter, an authors' form signed by all authors, and a cover letter describing any conflicts of interest related to the contents of the letter.
Letters commenting on an Annals article will be considered if they are received within 6 weeks of the time the article was published. Only some of the letters received can be published. Published letters are edited and may be shortened; tables and figures are included only selectively. Authors will be notified that the letter has been received. If the letter is selected for publication, the author will be notified about 3 weeks before the publication date. Unpublished letters cannot be returned.
Annals welcomes electronically submitted letters.
Top
Author & Article Info
References
Article
