Intravenous aminophylline increases the degree of saturation of urine with calcium phosphate and struvite

This study was designed to assess the effect of i.v. treatment with aminophylline (AMPH) on the risk of calcium phosphate and strutive stone formation. We administered AMPH in doses of 4 mg/kg body weight in 15-min i.v. infusions to 60 infants with clinical symptoms of obstructive bronchitis with dyspnoea. During 3 hours after infusion we observed a significant increase in urine saturation with brushite, octocalcium phosphate and struvite. This rise in urine saturation may increase the risk of kidney stone formation.