title: Sodium and fluid balance during hypotensive response to alpha-methyldopa.
abstract: 1. Detailed observations on sodium and fluid balance during treatment with alpha-methyldopa were made in five hypertensive patients. The initial fall in blood pressure concurred with a decline in fluid and sodium excretion. Sodium balance increased 100-300 mEq. In one patient with serve hypertension the sodium balance was incompletely restored, the relationship with blood pressure indicating a negative feedback loop. In the other patients sodium balance reverted to baseline, while the hypotensive response was maintained. This is probably due to a decrease in renal arteriolar tone. 2. Parallel systemic and renal vasodilatation may account for the discrepancy between a significant increase in blood volume and insignificant long-term changes in the fluid and sodium status.
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002986:Clinical Trials as Topic; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D008750:Methyldopa / Q000494:pharmacology* / Q000627:therapeutic use; D008875:Middle Aged; D012964:Sodium / Q000378:metabolism*; D013997:Time Factors; D014882:Water-Electrolyte Balance / Q000187:drug effects*
chemical_list: D008750:Methyldopa; D012964:Sodium