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Folic acid antagonists.

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H G PETERING. 1952. Folic acid antagonists.. https://doi.org/10.1152/physrev.1952.32.2.197

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Methotrexate for primary biliary cirrhosis.

BACKGROUND: Methotrexate, a folic acid antagonist with immunosuppressive properties, has been used to treat patients with primary biliary cirrhosis. The therapeutic responses to methotrexate in randomised clinical trials have been heterogeneous. OBJECTIVES: To assess the beneficial and harmful effects of methotrexate for patients with primary biliary cirrhosis. SEARCH STRATEGY: Relevant randomised clinical trials were identified by searching The Cochrane Hepato-Biliary Group Controlled Trials Register (June 2004), The Cochrane Central Register of Controlled Trials on The Cochrane Library (Issue 2, 2004), MEDLINE (January 1966 to August 2004), EMBASE (January 1980 to August 2004), and manual searches of bibliographies. We contacted authors of trials and pharmaceutical companies. SELECTION CRITERIA: Randomised clinical trials comparing methotrexate with placebo, no intervention, or another drug were included irrespective of blinding, language, year of publication, and publication status. DATA COLLECTION AND ANALYSIS: Our primary outcomes were mortality and mortality or liver transplantation. Dichotomous outcomes were reported as relative risk (RR) and hazard ratio (HR) if applicable. Continuous outcomes were reported as weighted mean difference (WMD). We examined intervention effects by using both a random-effects model and a fixed-effect model. Heterogeneity was investigated by subgroup analyses and sensitivity analyses. MAIN RESULTS: We identified four trials (370 patients) that compared methotrexate with placebo with or without ursodeoxycholic acid as co-intervention. One additional trial (87 patients) compared methotrexate with colchicine without and later with ursodeoxycholic acid as co-intervention. The methodological quality of the trials was low. We did not find significant effects of methotrexate on pruritus, fatigue, liver complications, liver biochemistry, liver histology, or adverse events. The pruritus score (WMD - 0.68, 95% CI - 1.11 to - 0.25), the levels of serum alkaline phosphatases (WMD - 0.41, 95% CI - 0.70 to - 0.12) and plasma immunoglobulin M (WMD - 0.47, 95% CI - 0.74 to - 0.20) were significantly lower in the patients receiving methotrexate. AUTHORS' CONCLUSIONS: Methotrexate increased mortality in patients with primary biliary cirrhosis. We do not recommend methotrexate for patients with primary biliary cirrhosis outside randomised trials.

Folic Acid Antagonists↗

Preliminary in vitro studies on two potent, water-soluble trimethoprim analogues with exceptional species selectivity against dihydrofolate reductase from Pneumocystis carinii and Mycobacterium avium.

2,4-Diamino-5-[3',4'-dimethoxy-5'-(5-carboxy-1-pentynyl)]benzylpyrimidine (6) and 2,4-diamino-5-[3',4'-dimethoxy-5'-(4-carboxyphenylethynyl)benzylpyrimidine (7) were synthesized from 2,4-diamino-5-(5'-iodo-3',4'-dimethoxybenzyl)pyrimidine (9) via a Sonogashira reaction with appropriate acetylenic esters followed by saponification, and were tested as inhibitors of dihydrofolate reductase (DHFR) from Pneumocystis carinii (Pc), Toxoplasma gondii (Tg), Mycobacterium avium (Ma), and rat in comparison with the widely used antibacterial agent 2,4-diamino-5-(3',4',5'-trimethoxybenzyl)pyrimidine (trimethoprim, TMP). The selectivity index (SI) for each compound was calculated by dividing its 50% inhibitory concentration (IC(50)) against rat DHFR by its IC(50) against Pc, Tg, or Ma DHFR. The IC(50) of 6 against Pc DHFR was 1.0 nM, with an SI of 5000. Compound 7 had an IC(50) of 8.2 nM against Ma DHFR, with an SI of 11000. By comparison, the IC(50) of TMP was 12000 nM against Pc, 300 nM against Ma, and 180000 against rat DHFR. The potency and selectivity values of 6 and 7 were not as high against Tg as they were against Pc or Ma DHFR, but nonetheless exceeded those of TMP. Because of the outstanding selectivity of 6 against Pc and of 7 against Ma DHFR, these novel analogues may be viewed as promising leads for further structure-activity optimization.

Folic Acid Antagonists↗