aminopyrine--dexamethasone--phenylbutazone--thiamine--vitamin-b12-drug-combination and Hypokalemia

The case of a 42-year-old man is reported, who on four occasions developed a hypokalaemic periodic paralysis after an intramuscular injection of "Ambene". The detailed examination of this patient shows, that it is the primary, autosomal dominant inherited form of hypokalaemic periodic paralysis, and not the secondary form, which is caused by a renal or gastrointestinal loss of potassium. Clinical and electrophysiological, as well as histopathological and electron microscopic findings are presented, showing the typical vacuolar myopathy with submicroscopic tubular structures. In the literature there is evidence for an increased sensitivity of the muscle membrane to insulin with an increased potassium-shift inside the cell in hypokalaemic periodic paralysis. "Ambene" is a combination, which contains amongst other substances dexamethasone and the local anaesthetic drug lidocain. In the present case the paresis was possibly caused by a combined effect of dexamethasone with a consequent hyperglycaemia and lidocain with a change in the excitability of the muscle membrane. The pathophysiological mechanism of hypokalaemic periodic paralysis is discussed in terms of the release by the combination of these two drugs. It has not previously been reported that "Ambene" can provoke a hypokalaemic periodic paralysis. This is a severe side effect because of the resulting cardiac and respiratory problems.

Topics: Adult; Aminopyrine; Anti-Inflammatory Agents; Back Pain; Dexamethasone; Drug Combinations; Humans; Hypokalemia; Injections, Intramuscular; Male; Muscles; Paralyses, Familial Periodic; Phenylbutazone; Potassium; Thiamine; Vitamin B 12