Bromocriptine

Bromocriptine
Clinical data
Trade names Originally Parlodel, subsequently many
Other names 2-Bromoergocriptine; CB-154
AHFS/Drugs.com Monograph, International Drug Names
MedlinePlus a682079
Pregnancy
category
  • AU: A
Routes of
administration
By mouth, vaginal, intravenous
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability 28% of oral dose absorbed
Metabolism Extensively liver-mediated
Elimination half-life 12–14 hours
Excretion 85% bile (feces), 2.5–5.5% urine
Identifiers
  • (5α)-2-Bromo-12-hydroxy-5-(2-methylpropyl)-3,6,18-trioxo-2-(propan-2-yl)ergotaman
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard 100.042.829
Chemical and physical data
Formula C32H40BrN5O5
Molar mass 654.606 g·mol−1
3D model (JSmol)
  • BrC1=C(C[C@H]2N(C)C3)C4=C(C=CC=C4C2=C[C@H]3C(N[C@]5(C(C)C)O[C@@]6(N([C@@H](CC(C)C)C(N7CCC[C@H]76)=O)C5=O)O)=O)N1
  • InChI=1S/C32H40BrN5O5/c1-16(2)12-24-29(40)37-11-7-10-25(37)32(42)38(24)30(41)31(43-32,17(3)4)35-28(39)18-13-20-19-8-6-9-22-26(19)21(27(33)34-22)14-23(20)36(5)15-18/h6,8-9,13,16-18,23-25,34,42H,7,10-12,14-15H2,1-5H3,(H,35,39)/t18-,23-,24+,25+,31-,32+/m1/s1 check
  • Key:OZVBMTJYIDMWIL-AYFBDAFISA-N check
  (verify)

Bromocriptine, originally marketed as Parlodel and subsequently under many brand names, is an ergoline derivative and dopamine agonist that is used in the treatment of pituitary tumors, Parkinson's disease, hyperprolactinaemia, neuroleptic malignant syndrome, and, as an adjunct, type 2 diabetes.

It was patented in 1968 and approved for medical use in 1975.

Medical uses

Bromocriptine is used to treat acromegaly and conditions associated with hyperprolactinemia like amenorrhea, infertility, hypogonadism, and prolactin-secreting adenomas. It is also used to prevent ovarian hyperstimulation syndrome and to treat Parkinson's disease.

Since the late 1980s it has been used, off-label, to reduce the symptoms of cocaine withdrawal but the evidence for this use is poor. Bromocriptine has been successfully used in cases of galactorrhea precipitated by dopamine antagonists like risperidone.

A quick-release formulation of bromocriptine, Cycloset, is also used to treat type 2 diabetes. When administered within 2 hours of awakening, it increases hypothalamic dopamine level and as a result decreases hepatic glucose production. It therefore acts as an adjunct to diet and exercise to improve glycemic control.

Side effects

Most frequent side effects are nausea, orthostatic hypotension, headaches, and vomiting through stimulation of the brainstem vomiting centre. Vasospasms with serious consequences such as myocardial infarction and stroke that have been reported in connection with the puerperium, appear to be extremely rare events. Peripheral vasospasm (of the fingers or toes) can cause Raynaud's Phenomenon. Bromocriptine use has been anecdotally associated with causing or worsening psychotic symptoms (its mechanism is in opposition of most antipsychotics, whose mechanisms generally block dopamine receptors). It should be understood, however, that the greater affinity bromocriptine and many similar antiparkinson's drugs have for the D2S receptor form (considered to be mostly present at inhibitory D2 autoreceptor locatations) relative to the D2L form, sufficiently low partial agonist activity (ie where a molecule binding to a receptor induces limited effects while preventing a stronger ligand like dopamine from binding), and, possibly, the functional selectivity of a particular drug may generate antidopaminergic effects that are more similar than oppositional in nature to antipsychotics. Pulmonary fibrosis has been reported when bromocriptine was used in high doses for the treatment of Parkinson's disease.

Use to suppress milk production after childbirth was reviewed in 2014 and it was concluded that in this context a causal association with serious cardiovascular, neurological or psychiatric events could not be excluded with an overall incidence estimated to range between 0.005% and 0.04%. Additional safety precautions and stricter prescribing rules were suggested based on the data. It is a bile salt export pump inhibitor.

After long-term use of dopamine agonists, a withdrawal syndrome may occur during dose reduction or discontinuation with the following possible side effects: anxiety, panic attacks, dysphoria, depression, agitation, irritability, suicidal ideation, fatigue, orthostatic hypotension, nausea, vomiting, diaphoresis, generalized pain, and drug cravings. For some individuals, these withdrawal symptoms are short-lived and they make a full recovery, for others a protracted withdrawal syndrome may occur with withdrawal symptoms persisting for months or years.

Pharmacology

Pharmacodynamics

Bromocriptine in a dopamine receptor bound conformation

Bromocriptine is a partial agonist of the dopamine D2 receptor. It also interacts with other dopamine receptors and with various serotonin and adrenergic receptors. Bromocriptine has additionally been found to inhibit the release of glutamate by reversing the GLT1 glutamate transporter.

As an antagonist of the serotonin 5-HT2B receptor, bromocriptine has not been associated with cardiac valvulopathy. This is in contrast to other ergolines acting instead as 5-HT2B receptor agonists such as cabergoline and pergolide but is similar to lisuride which likewise acts as a 5-HT2B receptor antagonist.

Activities of bromocriptine at various sites
Site Affinity (Ki [nM]) Efficacy (Emax [%]) Action
D1 692 ? ?
D2S 5.0 41 Partial agonist
D2L 15 28 Partial agonist
D3 6.8 68 Partial agonist
D4 372 0 Silent antagonist
D5 537 ? ?
5-HT1A 13 72 Partial agonist
5-HT1B 355 66 Partial agonist
5-HT1D 11 86 Partial agonist
5-HT2A 107 69 Partial agonist
5-HT2B 56 0 Silent antagonist
5-HT2C 741 79 Partial agonist
5-HT6 33 ? ?
5-HT7 11–126 ? ?
α1A 4.2 0 Silent antagonist
α1B 1.4 ? ?
α1D 1.1 ? ?
α2A 11 0 Silent antagonist
α2B 35 0 Silent antagonist
α2C 28 0 Silent antagonist
α2D 68 ? ?
β1 589 ? ?
β2 741 ? ?
H1 >10,000
M1 >10,000
Notes: All receptors are human except α2D-adrenergic, which is rat (no human counterpart), and 5-HT7, which is rat/mouse.

Chemistry

Like all ergopeptides, bromocriptine is a cyclol; two peptide groups of its tripeptide moiety are crosslinked, forming the >N-C(OH)< juncture between the two rings with the amide functionality.

Bromocriptine is a semisynthetic derivative of a natural ergot alkaloid, ergocryptine (a derivative of lysergic acid), which is synthesized by bromination of ergocryptine using N-bromosuccinimide.

History

Bromocriptine was discovered by scientists at Sandoz in 1965 and was first published in 1968; it was first marketed under the brand name Parlodel.

A quick-release formulation of bromocriptine was approved by the FDA in 2009.

Society and culture

Brand names

As of July 2017, bromocriptine was marketed under many brand names worldwide, including Abergin, Barlolin, Brameston, Brocriptin, Brom, Broma-Del, Bromergocryptine, Bromergon, Bromicon, Bromocorn, Bromocriptin, Bromocriptina, Bromocriptine, Bromocriptine mesilate, Bromocriptine mesylate, Bromocriptine methanesulfonate, Bromocriptini mesilas, Bromocriptinmesilat, Bromodel, Bromokriptin, Bromolac, Bromotine, Bromtine, Brotin, Butin, Corpadel, Cripsa, Criptine, Criten, Cycloset, Degala, Demil, Deparo, Deprolac, Diacriptin, Dopagon, Erenant, Grifocriptina, Gynodel, kirim, Kriptonal, Lactodel, Medocriptine, Melen, Padoparine, Palolactin, Parlodel, Pravidel, Proctinal, Ronalin, Semi-Brom, Serocriptin, Serocryptin, Suplac, Syntocriptine, Umprel, Unew, Updopa, Upnol B, and Volbro.

As of July 2017 it was also marketed as a combination drug with metformin as Diacriptin-M, and as a veterinary drug under the brand Pseudogravin.