Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hydralazine (1-hydrazinophthalazine) has been used extensively in the treatment of hypertension and congestive heart failure and produces arteriolar vasodilation, in part, mediated by prostaglandins. Its associated reflex baroreceptor-mediated responses of tachycardia and increased ejection velocity are attenuated in congestive heart failure. A direct inotropic effect has been attributed to the drug. Pharmacokinetic data indicate hydralazine is absorbed well from the gastrointestinal tract, and has an extensive and complex metabolism depending on acetylator status: slow acetylators undergo primary oxidative metabolism, while rapid acetylators are acetylated. Half-lives, clearances and bioavailability of the drug are not significantly altered in congestive heart failure compared with hypertensive patients. A wide range of dosages in heart failure has been noted (150 to 3000 mg/24h), and may related to a saturation of the first-pass effect. Hydralazine improves haemodynamics in the short term in patients with increased peripheral vascular resistance, and has variable effects on pulmonary capillary wedge and left ventricular filling pressures. Prediction of the short term clinical response is difficult and appears to be independent of pharmacokinetics. A meta analysis did not demonstrate long term efficacy of hydralazine alone in heart failure, but combination therapy with nitrates has been shown to improve survival and exercise performance in patients with mild to moderate heart failure. Side effects are common and are dependent on dose, duration and acetylator status.
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PMID:Clinical pharmacokinetics and therapeutic use of hydralazine in congestive heart failure. 265 46

During 1983, 38 patients with pregnancy-induced hypertension were treated with hydralazine-apresoline (1-hydrazinophthalazine). During the course of their treatment, five of these patients showed evidence of the HELLP syndrome described by Weinstein (hemolysis, thrombocytopenia, and elevated liver enzymes). Evidence is presented on the role of hydralazine in producing hepatocellular damage. Liver function is compromised during the natural course of pregnancy-induced hypertension, and 5-10% of preeclamptic patients develop the HELLP syndrome. In many places hydralazine is the drug of choice in the treatment of pregnancy-induced hypertension.
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PMID:Hydralazine-induced hepatitis in pregnancy. 289 36