Acute overdosage may produce acute hypotension with other responses attributable to brain and gastrointestinal malfunction (excessive sedation, weakness, bradycardia, dizziness, lightheadedness, constipation, distention, flatus, diarrhea, nausea, vomiting).
In the event of overdosage, symptomatic and supportive measures should be employed. When ingestion is recent, gastric lavage or emesis may reduce absorption. Otherwise, management includes special attention to cardiac rate and output, blood volume, electrolyte imbalance, paralytic ileus, urinary function and cerebral activity.
Sympathomimetic drugs [e.g., levarterenol, epinephrine, ARAMINE * (Metaraminol Bitartrate)] may be indicated. Methyldopa is dialyzable. The degree to which chlorothiazide is removed by hemodialysis has not been established.
The oral LD50 of methyldopa is greater than 1.5 g/kg in both the mouse and the rat. The oral LD50 of chlorothiazide is 8.5 g/kg, greater than 10 g/kg, and greater than 1 g/kg in the mouse, rat, and dog respectively.
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