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Published on: March 28, 2017
Metabolic correlates of theophylline therapy: a concentration-related phenomenon
J M Flack1, K W Ryder, D Strickland
1Department of Medicine, University of Minnesota Medical School, Minneapolis 55455.
Objective:
To determine the relationship of serum theophylline concentration with electrolyte and glucose abnormalities across a broad range of theophylline concentrations.
Design:
Retrospective review of a computerized laboratory database between June 1, 1984 and June 1, 1986.
Setting:
A midwestern university medical center.
Patients:
Eight hundred sixty-nine patients with serum theophylline concentrations of > 5.5 mumol/L and a random unmatched sample (control group) of 350 in- and outpatient adults and children with no history of reactive airways disease or theophylline exposure.
Results:
Patients with measurable theophylline had a higher risk of hypokalemia, hyponatremia, hyperglycemia, hypophosphatemia, and hypomagnesemia compared with the unexposed control group. Unadjusted odds ratios (OR) were: (1) hypokalemia OR = 4.2 (95 percent CI 2.2 to 7.9); (2) hyponatremia OR = 5.4 (95 percent CI 2.0 to 12.9); (3) hypomagnesemia OR = 1.6 (95 percent CI 1.0 to 2.5); (4) hyperglycemia OR = 2.3 (95 percent CI 1.7 to 3.0); and (5) hypophosphatemia OR = 2.7 (95 percent CI 1.2 to 5.3). A linear concentration-response relationship was documented between serum theophylline concentration and all metabolic disturbances.
Conclusions:
Measurable theophylline was associated with increased risk for glucose and electrolyte abnormalities in a concentration-related fashion across a broad range of theophylline concentrations from 5.5 to > or = 110 mumol/L.
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