Which medication is specifically mentioned to inhibit dopamine and stimulate prolactin?

Metoclopramide is a medication that has been specifically indicated to inhibit dopamine receptors and, as a result, stimulate the secretion of prolactin from the pituitary gland. Prolactin is the hormone responsible for milk production in breastfeeding mothers, making this medication relevant in the context of enhancing lactation.

This action occurs because dopamine generally acts to inhibit prolactin secretion; by blocking dopamine receptors, metoclopramide leads to increased levels of prolactin. This mechanism is particularly significant in situations where a mother may be experiencing low milk supply, as increasing prolactin can help stimulate breast milk production.

In contrast, the other medications listed do not have this specific effect on prolactin secretion. Ranitidine is mainly used to reduce stomach acid and does not influence prolactin levels. Domperidone, while it also acts on dopamine receptors to enhance prolactin levels, is not mentioned here in the context of this question. Propranolol is a beta-blocker used primarily for cardiovascular conditions and does not have a role in regulating prolactin or affecting breastfeeding directly.