The effect of delayed gastric emptying and absorption on pharmacokinetic parameters of lithium.

Gastrointestinal motility is one of the most important factors than can influence drug absorption from gastrointestinal tract. The aim of the present study was to investigate the effect of delayed gastric emptying and intestinal transit on pharmacokinetic parameters of lithium. Treatment animals were administered an anticholinergic agent (propantheline bromide, 4 mg/kg, p.o.) 10 min before lithium chloride (1.5 mM/kg, p.o.) administration, whereas the control group was administered the same dose of lithium p.o., alone. Plasma lithium levels were measured by flame spectrophotometry and calculated with a computer programme (SIPHAR). Differences detected in AUC, fractionated AUC values, Cmax and tmax suggest that using delayed absorption process, it is possible to prolong by 272% the plateau time of the drug in the therapeutic range and this approach might be an alternative way to prevent some undesirable effects due to peak plasma levels above the maximal therapeutic level. This approach might be more important as an alternative for suitable slow release formulations.