Acute hypomagnesaemia complicating the treatment of meconium ileus equivalent in cystic fibrosis.

Meconium ileus equivalent (MIE) is a common and often recurrent complication in adolescent and adult patients with cystic fibrosis (CF). MIE is characterized by partial or complete bowel obstruction, resulting from abnormally viscid mucofaeculant material in the terminal ileum and right colon. Patients present with recurrent abdominal pain, intestinal obstruction, and/or a palpable faecal mass. Conventional treatment consists of the oral and rectal administration of the mucolytic agent N-acetylcysteine, and hypertonic solutions of sodium diatrizoate. We describe the occurrence of acute decreases in plasma magnesium in all of seven patients treated with this regimen with marked hypomagnesaemia (less than 0.70 mmol/l) in four of the seven patients. No changes in plasma sodium, potassium, or calcium were observed.