Dose-dependent constipation with higher doses of quetiapine: a case series.

Quetiapine is a dopamine D2 and serotonin 5-HT2 antagonist with antipsychotic and mood-stabilizing properties. Recent studies suggest that higher doses of quetiapine combine superior therapeutic efficacy with good tolerability. We present five patients, in whom treatment with higher doses of quetiapine was associated with constipation. Our observations raise the question of dose-dependent constipation under treatment with quetiapine.