This report describes a patient with mixed normal anion gap hyperchloremic
metabolic and respiratory acidosis associated with hypokalemia attributed t
o cough mixture abuse. Metabolic acidosis was likely related to an overdose
of ammonium chloride, whereas respiratory acidosis was probably related to
the effect of hypokalemia on respiratory muscles, causing hypoventilation,
Hypokalemia was caused by a transcellular shift of potassium Induced by ep
hedrine and pseudoephedrine. Both ammonium chloride and ephedrine were prob
ably present in the cough mixture obtained by our patient as an over-the-co
unter medication. Physicians should be aware of the potential for cough mix
ture abuse to cause major electrolyte disturbances that may carry the risk
for major cardiac arrhythmias, particularly in youth. (C) 2001 by the Natio
nal Kidney Foundation, Inc.