<prompt> Alpha-methyldopa is primarily used forPregnancy induced hypeensionRenovascular hypeensionFirst line agent in hypeensionRefractory hypeension  <response>: They act on central alpha 2a receptors to decrease efferent sympathetic activity. It decreases t.p.r more than H.R or C.O It is infrequently used now. Ref: Essentials of medical pharmacology, K.D Tripathi, 7th edition, page 566 