Steady-state serum concentrations of imipramine, its main metabolites and clinical response in primary enuresis.

Thirty-seven children (6-13 years old), receiving a flexible dosage of imipramine (IMI) for nocturnal enuresis, were evaluated. After a mean time of 8.5 +/- 7.0 weeks of therapy, 40.5% no longer wet the bed; 32.4% had a mean benefit of 80%; 27.01% had a negligible response. The best relationship observed was between clinical effect and drug serum concentrations rather than with drug daily dose, the most satisfactory being that with IMI seric values (P = 0.019). Responders (effect higher than 50%) had higher IMI serum concentrations (P less than 0.05) than poor responders. At 3 and 6 months after stopping the drug, over 90% of the responders maintained the maximum response reached during treatment. The side-effects observed were irritability, reduction of appetite, headache, a mild increase of blood pressure.