Managing patients with antipsychotic drug-induced hyperprolactinaemia

Classics in Chemical Neuroscience: Aripiprazole

Aripiprazole was the first antipsychotic developed to possess agonist properties at dopamine D₂ autoreceptors, a groundbreaking strategy that presented a new vista for schizophrenia drug discovery. The dopamine D₂ receptor is the crucial target of all extant antipsychotics, and all developed prior to aripiprazole were D₂ receptor antagonists. Extensive blockade of these receptors, however, typically produces extrapyramidal (movement) side effects, which plagued first-generation antipsychotics, such as haloperidol. Second-generation antipsychotics, such as clozapine, with unique polypharmacology and D₂ receptor binding kinetics, have significantly lower risk of movement side effects but can cause myriad additional ones, such as severe weight gain and metabolic dysfunction. Aripiprazole's polypharmacology, characterized by its unique agonist activity at dopamine D₂ and D₃ and serotonin 5-HT_1A receptors, as well as antagonist activity at serotonin 5-HT_2A receptors, translates to successful reduction of positive, negative, and cognitive symptoms of schizophrenia, while also mitigating risk of weight gain and movement side effects. New observations, however, link aripiprazole to compulsive behaviors in a small group of patients, an unusual side effect for antipsychotics. In this review, we discuss the chemical synthesis, pharmacology, pharmacogenomics, drug metabolism, and adverse events of aripiprazole, and we present a current understanding of aripiprazole's neurotherapeutic mechanisms, as well as the history and importance of aripiprazole to neuroscience.

Clinical Management of Antipsychotic-Induced Hyperprolactinemia

PURPOSE

This article describes the physiology and mechanisms of prolactin and the assessment and clinical management strategies of antipsychotic-induced hyperprolactinemia.

CONCLUSIONS

Hyperprolactinemia is a disorder of the hypothalamic-pituitary axis which can be caused by several mechanisms. Typical antipsychotic agents are more likely to cause hyperprolactinemia than atypical antipsychotic agents, with the exception of amisulpride, paliperidone, and risperidone.

PRACTICE IMPLICATIONS

Switching from prolactin-elevating to prolactin-sparing agents is recommended. Providing adjunctive treatment and prescribing substitutive hormones are alternatives. Education and lifestyle modification should be a major health promotion strategy. Taking patients' history and conducting physical examinations should be done during follow-up.