Common side effects include increased weight, sleepiness, and dizziness.[1] Serious side effects may include mania, low white blood cell count, and increased suicide among children.[9] Withdrawal symptoms may occur with stopping.[12] It is not recommended together with an MAO inhibitor.[9] It is unclear if use during pregnancy is safe.[9] How it works is not clear, but it may involve blocking certain adrenergic and serotonin receptors.[8][9] Chemically, it is a tetracyclic antidepressant (TeCA).[9] It also has strong antihistaminergic effects.[8][9]