Antipsychotics, mainly typical/classic antipsychotics, may cause hyperprolactinaemia because they block the dopamine receptors in the tuberoinfundibular pathway, which is responsible for the secretion of prolactin. Dopamine released in the tuberoinfundibular pathway binds to D2 receptors and inhibits the secretion of prolactin. If the dopamine receptors in this pathway are blocked by typical/classic antipsychotics, dopamine won’t be able to bind to them and inhibit the secretion of prolactin. Therefore, the amount of prolactin in the blood will increase! Besides typical/classic antipsychotics like haloperidol, some atypical antipsychotics such as risperidone and paliperidone can also have this side effect! (In fact, risperidone and paliperidone are said to be the most “typical” from the atypical antipsychotics!) I hope this helps 😊
