Trial of the prophylactic effect of diazoxide in the treatment of familial periodic hypokalemia.

Five patients suffering from familial periodic paralysis with hypokalemia (FPP) were exposed to standard paralysis induction trials which elicited total paralyysis and hypokalemia. In all cases the serum potassium fell to or below 2.6 mmol/1. After being pre-treated with diazoxide for 72 h, the same five patients were exposed to the same standardized paralysis induction procedure. None of them developed any demonstrable symptoms or signs of paralysis. In one the serum potassium dropped to 3.2 mmol/1, but in all the others the levels were higher. The serum glucose level was significant higher (P less than 0.01), the serum insulin level was significant lower (P less than 0.01) when induction of paralysis was attempted under diazoxide cover than during the untreated stimulation phase. Three patients were put on prophylactic diazoxide medication. After a few months, without paralytic episodes or other prophylactic drugs, adaptation to the diazoxide occurred and the previous, frequent paralytic episodes returned in unchanged severity. This experimental prophylactic effect of diazoxide supports the hypothesis that the glucose deposition in muscles is a major step in eliciting the parese attacks in FPP.