RESUMEN
The acute blood pressure response to the angiotensin converting enzyme inhibitor, captopril, was used to measure participation of the renin-angiotensin system in treatment-resistant hypertension. By 2 h after a single 25-mg oral captopril dose in patients still receiving a diuretic-vasodilator-beta-blocker combination, systolic and diastolic blood pressures had fallen significantly; the decrease in diastolic pressure correlated with the control (immediately pre-captopril) plasma renin activity (r = 0.64, p less than 0.001). Apart from its possible contribution to the underlying hypertension, this captopril-identified renin component may have reflected diuretic and vasodilator-induced renin stimulation that could not adequately be prevented by the renin-lowering properties of the beta-blocker. Captopril, and perhaps other specific antirenin drugs, therefore, may be valuable adjuncts to treatment in patients with hypertension refractory to conventional therapy.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina , Captopril/uso terapéutico , Hipertensión Renal/tratamiento farmacológico , Hipertensión Renovascular/tratamiento farmacológico , Hipertensión/tratamiento farmacológico , Prolina/análogos & derivados , Sistema Renina-Angiotensina/efectos de los fármacos , Adulto , Aldosterona/sangre , Presión Sanguínea/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Renina/sangreAsunto(s)
Antagonistas Adrenérgicos beta/administración & dosificación , Diuréticos/administración & dosificación , Hipertensión/tratamiento farmacológico , Aldosterona/orina , Análisis de Varianza , Población Negra , Presión Sanguínea/efectos de los fármacos , Quimioterapia Combinada , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hidroclorotiazida/administración & dosificación , Hidroclorotiazida/farmacología , Masculino , Metoprolol/administración & dosificación , Metoprolol/farmacología , Persona de Mediana Edad , Postura , Potasio/sangre , Renina/sangreRESUMEN
Although deleterious events following abrupt withdrawal of antihypertensive treatment are relatively uncommon, considerable attention has recently been focused on this problem. A withdrawal syndrome may occur after termination of almost all types of antihypertensive drugs, but most experience has been with the centrally acting agents and with beta-adrenoreceptor blockers. Abrupt discontinuation of high doses of centrally acting drugs such as alpha-methyldopa, clonidine, and guanabenz can produce a syndrome of sympathetic overactivity that includes agitation, headache, sweating, and nausea and less commonly can provoke rapid upswings in blood pressure. If beta blockers are suddenly stopped, a similar pattern can occur that may be related to excessive activity of thyroid hormones as well as sympathetic factors. Additionally, patients with ischemic heart disease may be susceptible to an acute exacerbation of their cardiac disease when beta-blocker treatment is stopped. It seems likely that discontinuation events can be particularly severe when combinations of different types of antihypertensive medications are sud-disease when betablocker treatment is denly stopped. This problem can be dealt with by educating patients to avoid sudden drug cessation and when elective discontinuation is planned, by gradual dose reduction.