Compartmental Shift of Potassium—A Result of Sympathomimetic Overdose

Abstract

A 17-year-old youth was admitted with a serum potassium concentration of 1.8 mmol/l after taking an overdose of pseudoephedrine and choline theophyllinate. Apart from tachycardia, tachypnoea and ankle clonus, examination was normal as was the initial electrocardiograph. The hypokalaemia resolved, but there was an overall positive potassium balance of only 13 mmol. This suggests that the sympathomimetics provoked a compartmental shift of potassium perhaps indirectly by inducing hyperglycaemia and hyperinsulinaemia, as well as directly. Other factors known to affect body potassium distribution were excluded. The fact that features commonly associated with hypokalaemia could not be demonstrated may be explained by a normal body potassium content. Severe hypokalaemia caused by a compartmental shift occurs with large doses of sympathomimetics as well as in periodic paralysis.

The history of Ephedra (ma-huang)

“…Intermittent bouts of paranoid psychosis may occur associated with suicidal (or homicidal) behaviour. [17][18][19] A gradual reduction of dose is required together with an administration of oral (or even intravenous) benzodiazepines. These symptoms produced by ephedrine closely resemble those of amphetamine (speed) or methamphetamine (crystal meth), compounds commonly associated with illegal street dealing.…”

“…On the whole, the symptoms produced by ephedrine withdrawal tend to be less severe and less prolonged than those seen after withdrawal from amphetamines. [17][18][19] The search for better bronchodilators From 1950, the use of ephedrine began to decline with the emergence of other drug groups, such as the methylxanthines (theophylline) and the corticosteroids (hydrocortisone and prednisolone), which could be used alone or in conjunction with the catecholamine.…”

Hypokalemia After Theophylline Intoxication

“…21,22,27"29 In animals, epinephrine infusion de¬ creases the lethality of potassium chloride injection.27 Epinephrine-induced hypokalemia does not appear to be the consequence of altered renal potassium disposal or changes in plasma renin, aldosterone, insulin, or total body potas¬ sium. 18,28 The hypercatecholaminemia of theophylline intoxication has other potential consequences. Increased plasma catecholamine activity is the presumed mediator of hyperglycemia, hypercalcemia, and metabolic acidosis.1,2,6 Elevated catechol-amines also lead to prolongation ofthe Q-T interval on electro¬ cardiogram and may be a cause of theophylline-induced tachyarrhythmias.U5,26…”