Metergoline Explained

Metergoline, also known as methergoline and sold under the brand names Contralac (veterinary) and Liserdol (clinical), is a monoaminergic medication of the ergoline group which is used as a prolactin inhibitor in the treatment of hyperprolactinemia (high prolactin levels) and to suppress lactation.^{[1] [2] [3]}

Pharmacology

Pharmacodynamics

Metergoline is a ligand of various serotonin and dopamine receptors.^{[4] [5]}

! Site! Affinity (K_i [nM])! Efficacy (E_max [%])! Action

5-HT1A	4.3	?	Agonist
5-HT1B	5.2–36	?	Partial agonist
5-HT1D	0.60–11.7	?	Partial agonist
5-HT1E	776–1,122	?	?
5-HT1F	339–341	?	?
5-HT2A	0.12–2.3	?	Antagonist
5-HT2B	0.71–1.8	?	Antagonist
5-HT2C	0.18–1.8	?	Antagonist
5-HT3	>5,000–7,400	?	?
5-HT4	354	?	?
5-HT5A	630	?	?
5-HT5B	1,000	?	?
5-HT6	61–400	?	?
5-HT7	6.4–6.5	?	Antagonist
D2	?	?	Agonist
Notes: All sites are human except 5-HT3 (rat/pig), 5-HT4 (pig), and 5-HT5B (rat—no human counterpart).

Notes and References

1. Book: Index Nominum 2000: International Drug Directory. 2000. Taylor & Francis. 978-3-88763-075-1. 661–.
2. Book: Plumb DC . Metergoline . Plumb's Veterinary Drug Handbook: Pocket. https://books.google.com/books?id=wshQDwAAQBAJ&pg=PA1057 . 21 February 2018. John Wiley & Sons. 978-1-119-34649-4. 1057–.
3. Book: Johson CA . False Pregnancy, Disorders of Pregnancy and Parturition, and Mismating . Nelson RW, Couto CG . Small Animal Internal Medicine - E-Book. https://books.google.com/books?id=s-TXrwyo-_YC&pg=PA927. 2 December 2008. Elsevier Health Sciences. 978-0-323-06512-2. 927–.
4. Hamon M, Mallat M, Herbet A, Nelson DL, Audinot M, Pichat L, Glowinski J . [3H]Metergoline: a new ligand of serotonin receptors in the rat brain . Journal of Neurochemistry . 36 . 2 . 613–626 . February 1981 . 7463079 . 10.1111/j.1471-4159.1981.tb01634.x . 20259621 .
5. Miller KJ, King A, Demchyshyn L, Niznik H, Teitler M . Agonist activity of sumatriptan and metergoline at the human 5-HT_1D beta receptor: further evidence for a role of the 5-HT_1D receptor in the action of sumatriptan . European Journal of Pharmacology . 227 . 1 . 99–102 . September 1992 . 1330643 . 10.1016/0922-4106(92)90149-P .