Abstract
In a rat model of dual infection, we studied such dihydrofolate reductase (DHFR) inhibitors as PS-15 (25 mg/kg of body weight), epiroprim (100 mg/kg), and pyrimethamine (3 mg/kg) alone or in combination with various doses of dapsone (50, 25, or 5 mg/kg) for the prevention of pneumocystosis and toxoplasmosis. Rats latently infected with Pneumocystis carinii were immunosuppressed by corticosteroids for 7 weeks, and the drugs were administered from the initiation of the corticosteroid treatment. At week 5, the rats were inoculated intraperitoneally with the RH strain of Toxoplasma gondii. Infections were monitored by the counting of P. carinii cysts in lung homogenates and the titration of T. gondii in organs by quantitative culture and an indirect immunofluorescence assay. Fourteen of the 15 untreated rats died after T. gondii challenge, with P. carinii infection in the lungs and T. gondii infection in the lungs, liver, spleen, and brain. Of the three tested DHFR inhibitors, only PS-15 exhibited anti-P. carinii activity; none prevented toxoplasmosis in 100% of the rats. After the DHFR inhibitors were combined with dapsone (50 or 25 mg/kg), both pneumocystosis and toxoplasmosis were completely prevented. On the basis of these results, PS-15 and epiroprim combined with dapsone are candidates for use for the prevention of both pneumocystosis and toxoplasmosis.
Full Text
The Full Text of this article is available as a PDF (179.8 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bozzette S. A., Finkelstein D. M., Spector S. A., Frame P., Powderly W. G., He W., Phillips L., Craven D., van der Horst C., Feinberg J. A randomized trial of three antipneumocystis agents in patients with advanced human immunodeficiency virus infection. NIAID AIDS Clinical Trials Group. N Engl J Med. 1995 Mar 16;332(11):693–699. doi: 10.1056/NEJM199503163321101. [DOI] [PubMed] [Google Scholar]
- Brun-Pascaud M., Chau F., Simonpoli A. M., Girard P. M., Derouin F., Pocidalo J. J. Experimental evaluation of combined prophylaxis against murine pneumocystosis and toxoplasmosis. J Infect Dis. 1994 Sep;170(3):653–658. doi: 10.1093/infdis/170.3.653. [DOI] [PubMed] [Google Scholar]
- Canfield C. J., Milhous W. K., Ager A. L., Rossan R. N., Sweeney T. R., Lewis N. J., Jacobus D. P. PS-15: a potent, orally active antimalarial from a new class of folic acid antagonists. Am J Trop Med Hyg. 1993 Jul;49(1):121–126. doi: 10.4269/ajtmh.1993.49.121. [DOI] [PubMed] [Google Scholar]
- Carr A., Gross A. S., Hoskins J. M., Penny R., Cooper D. A. Acetylation phenotype and cutaneous hypersensitivity to trimethoprim-sulphamethoxazole in HIV-infected patients. AIDS. 1994 Mar;8(3):333–337. doi: 10.1097/00002030-199403000-00006. [DOI] [PubMed] [Google Scholar]
- Carr A., Tindall B., Penny R., Cooper D. A. Trimethoprim-sulphamethoxazole appears more effective than aerosolized pentamidine as secondary prophylaxis against Pneumocystis carinii pneumonia in patients with AIDS. AIDS. 1992 Feb;6(2):165–171. doi: 10.1097/00002030-199202000-00004. [DOI] [PubMed] [Google Scholar]
- Chang H. R., Arsenijevic D., Comte R., Polak A., Then R. L., Pechère J. C. Activity of epiroprim (Ro 11-8958), a dihydrofolate reductase inhibitor, alone and in combination with dapsone against Toxoplasma gondii. Antimicrob Agents Chemother. 1994 Aug;38(8):1803–1807. doi: 10.1128/aac.38.8.1803. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Comley J. C., Sterling A. M. Artificial infections of Pneumocystis carinii in the SCID mouse and their use in the in vivo evaluation of antipneumocystis drugs. J Eukaryot Microbiol. 1994 Nov-Dec;41(6):540–546. doi: 10.1111/j.1550-7408.1994.tb01514.x. [DOI] [PubMed] [Google Scholar]
- Derouin F., Piketty C., Chastang C., Chau F., Rouveix B., Pocidalo J. J. Anti-Toxoplasma effects of dapsone alone and combined with pyrimethamine. Antimicrob Agents Chemother. 1991 Feb;35(2):252–255. doi: 10.1128/aac.35.2.252. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Girard P. M., Landman R., Gaudebout C., Olivares R., Saimot A. G., Jelazko P., Gaudebout C., Certain A., Boué F., Bouvet E. Dapsone-pyrimethamine compared with aerosolized pentamidine as primary prophylaxis against Pneumocystis carinii pneumonia and toxoplasmosis in HIV infection. The PRIO Study Group. N Engl J Med. 1993 May 27;328(21):1514–1520. doi: 10.1056/NEJM199305273282102. [DOI] [PubMed] [Google Scholar]
- Gosey L. L., Howard R. M., Witebsky F. G., Ognibene F. P., Wu T. C., Gill V. J., MacLowry J. D. Advantages of a modified toluidine blue O stain and bronchoalveolar lavage for the diagnosis of Pneumocystis carinii pneumonia. J Clin Microbiol. 1985 Nov;22(5):803–807. doi: 10.1128/jcm.22.5.803-807.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hardy W. D., Feinberg J., Finkelstein D. M., Power M. E., He W., Kaczka C., Frame P. T., Holmes M., Waskin H., Fass R. J. A controlled trial of trimethoprim-sulfamethoxazole or aerosolized pentamidine for secondary prophylaxis of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome. AIDS Clinical Trials Group Protocol 021. N Engl J Med. 1992 Dec 24;327(26):1842–1848. doi: 10.1056/NEJM199212243272604. [DOI] [PubMed] [Google Scholar]
- Hoover D. R., Saah A. J., Bacellar H., Phair J., Detels R., Anderson R., Kaslow R. A. Clinical manifestations of AIDS in the era of pneumocystis prophylaxis. Multicenter AIDS Cohort Study. N Engl J Med. 1993 Dec 23;329(26):1922–1926. doi: 10.1056/NEJM199312233292604. [DOI] [PubMed] [Google Scholar]
- Hughes W. T., Jacobus D. P., Canfield C., Killmar J. Anti-Pneumocystis carinii activity of PS-15, a new biguanide folate antagonist. Antimicrob Agents Chemother. 1993 Jul;37(7):1417–1419. doi: 10.1128/aac.37.7.1417. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hughes W. T., Killmar J. T., Oz H. S. Relative potency of 10 drugs with anti-Pneumocystis carinii activity in an animal model. J Infect Dis. 1994 Oct;170(4):906–911. doi: 10.1093/infdis/170.4.906. [DOI] [PubMed] [Google Scholar]
- Jorde U. P., Horowitz H. W., Wormser G. P. Utility of dapsone for prophylaxis of Pneumocystis carinii pneumonia in trimethoprim-sulfamethoxazole-intolerant, HIV-infected individuals. AIDS. 1993 Mar;7(3):355–359. doi: 10.1097/00002030-199303000-00008. [DOI] [PubMed] [Google Scholar]
- Kovacs J. A., Allegra C. J., Beaver J., Boarman D., Lewis M., Parrillo J. E., Chabner B., Masur H. Characterization of de novo folate synthesis in Pneumocystis carinii and Toxoplasma gondii: potential for screening therapeutic agents. J Infect Dis. 1989 Aug;160(2):312–320. doi: 10.1093/infdis/160.2.312. [DOI] [PubMed] [Google Scholar]
- Martinez A., Allegra C. J., Kovacs J. A. Efficacy of epiroprim (Ro11-8958), a new dihydrofolate reductase inhibitor, in the treatment of acute Toxoplasma infection in mice. Am J Trop Med Hyg. 1996 Mar;54(3):249–252. doi: 10.4269/ajtmh.1996.54.249. [DOI] [PubMed] [Google Scholar]
- Mehlhorn H., Dankert W., Hartman P. G., Then R. L. A pilot study on the efficacy of epiroprim against developmental stages of Toxoplasma gondii and Pneumocystis carinii in animal models. Parasitol Res. 1995;81(4):296–301. doi: 10.1007/BF00931533. [DOI] [PubMed] [Google Scholar]
- Meyer S. C., Majumder S. K., Cynamon M. H. In vitro activities of PS-15, a new dihydrofolate reductase inhibitor, and its cyclic metabolite against Mycobacterium avium complex. Antimicrob Agents Chemother. 1995 Aug;39(8):1862–1863. doi: 10.1128/aac.39.8.1862. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Piketty C., Derouin F., Rouveix B., Pocidalo J. J. In vivo assessment of antimicrobial agents against Toxoplasma gondii by quantification of parasites in the blood, lungs, and brain of infected mice. Antimicrob Agents Chemother. 1990 Aug;34(8):1467–1472. doi: 10.1128/aac.34.8.1467. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schneider M. M., Hoepelman A. I., Eeftinck Schattenkerk J. K., Nielsen T. L., van der Graaf Y., Frissen J. P., van der Ende I. M., Kolsters A. F., Borleffs J. C. A controlled trial of aerosolized pentamidine or trimethoprim-sulfamethoxazole as primary prophylaxis against Pneumocystis carinii pneumonia in patients with human immunodeficiency virus infection. The Dutch AIDS Treatment Group. N Engl J Med. 1992 Dec 24;327(26):1836–1841. doi: 10.1056/NEJM199212243272603. [DOI] [PubMed] [Google Scholar]
- Then R. L., Böhni E., Angehrn P., Plozza-Nottebrock H., Stoeckel K. New analogs of trimethoprim. Rev Infect Dis. 1982 Mar-Apr;4(2):372–377. doi: 10.1093/clinids/4.2.372. [DOI] [PubMed] [Google Scholar]
- Walzer P. D., Foy J., Steele P., White M. Synergistic combinations of Ro 11-8958 and other dihydrofolate reductase inhibitors with sulfamethoxazole and dapsone for therapy of experimental pneumocystosis. Antimicrob Agents Chemother. 1993 Jul;37(7):1436–1443. doi: 10.1128/aac.37.7.1436. [DOI] [PMC free article] [PubMed] [Google Scholar]