Possible Interaction: Potassium and Theophylline

“ Theophylline by itself causes a slight decrease in plasma potassium concentration.”

“ Theophylline was less potent in relaxing the potassium induced contraction.”

“Toxic levels of theophylline are also associated with a fall in potassium which could potentiate theophylline-induced seizures.”

“Both 0.5 … 5 mM theophylline … net potassium secretion by 0.49 +/- 0.04 and 0.33 +/- 0.03 microEq/h X cm2, p less than 0.001, respectively; … secretion was secondary to an increase in serosal-to-mucosal potassium transport without change in mucosal-to-serosal potassium movement.”

“ TH , at all doses that increased urinary PGE2 excretion, also caused dose-related 2-to 4-fold increases in urine volume and urinary excretion of sodium and potassium.”

“Thus, isoproterenol and theophylline , two agents that can relax ureteral segments previously contracted by a depolarizing concentration of potassium , could presumably increase cyclic AMP levels, isoproterenol by increasing synthesis and theophylline by decreasing degradation.”

“The increases in osmotic water permeability caused by vasopressin or cyclic AMP were unaffected by a serosal potassium concentration of 21.5 mM. The increase in osmotic water permeability caused by theophylline was inhibited by 21.5 mM potassium.”

“The same concentration of potassium in the bathing medium inhibited the increase in short-circuit current caused by theophylline.”

“The effect of raised potassium levels on dopamine-β-hydroxylase activity was potentiated by theophylline.”

“ Theophylline enhanced the potassium effects.”