Methyldopa Liver Damage

Twenty patients are described in whom liver damage appeared to be directly related to the administration of methyldopa. Sixteen had hepatitic syndromes from which they recovered on stopping methyldopa; four of these patients had recurrences of jaundice after a second course of the drug. Features suggestive of active chronic hepatitis were found in two patients. There were two deaths attributed to methyldopa, one of these being in a patient with pre-existing undiagnosed macronodular cirrhosis.     

Interaction between Levodopa and Methyldopa

The interaction between methyldopa and levodopa was studied in 18 patients with Parkinsonism. Together they produced a fall in blood pressure in doses which when given alone had no effect or only a slight hypotensive effect. Severe hypotension never occurred. It is reasonable to give methyldopa to hypertensive patients on levodopa but the regimen should be initiated in hospital.     

Enhancement of Methyldopa Metabolism with Barbiturate

The spurious increase in serum catecholamine levels associated with methyldopa treatment can be reduced by the simultaneous administration of phenobarbitone. This accelerating effect of phenobarbitone on methyldopa metabolism has been demonstrated in relation to both adrenaline and noradrenaline, and investigations suggest that it is due to the effect of barbiturate on the activity of metabolizing enzymes.