Figure 2. Mechanisms of drug-induced hyperprolactinemia with selected examples (adopted from La Torre et al. (2). In addition to opiates, cholinomimetics, PPIs and smoking indirectly also stimulate the opioid receptors. PPIs, Protein pump inhibitors; TCAs, tricyclic anti-depressants; MAO, monoamine oxidase; SSRIs, selective serotonin reuptake inhibitors; SNRIs, serotonin-noradrenaline reuptake inhibitors.