Quetiapine for Tamoxifen-Induced Insomnia in Women With Breast Cancer

Background Insomnia is a frequent adverse effect reported by women taking tamoxifen, an estradiol receptor-antagonist, for breast cancer. Objective The authors report on six patients treated with quetiapine, an atypical antipsychotic, for tamoxifen-related insomnia without depression. Method Quetiapine was started at 25 mg/day 1 hour before bedtime; dose adjustments upward were made in 25-mg increments, titrated to a maximum dose of 100 mg according to therapeutic response and tolerance. Results Five of the six women showed a prompt improvement of their insomnia; this effect was maintained after 6 weeks of treatment. Discussion Quetiapine might improve sleep alterations because of its high affinity for serotonergic receptors, enhancing central serotonergic neurotransmission, thus possibly decreasing excitatory glutamatergic transmission.