Bromocriptine

Oral (L1934). Approximately 28% of the oral dose is absorbed; however due to a substantial first pass effect, only 6% of the oral dose reaches the systemic circulation unchanged. Bromocriptine and its metabolites appear in the blood as early as 10 minutes following oral administration and peak plasma concentration are reached within 1-1.5 hours. Serum prolactin may be decreased within 2 hours or oral administration with a maximal effect achieved after 8 hours. Growth hormone concentrations in patients with acromegaly is reduced within 1-2 hours with a single oral dose of 2.5 mg and decreased growth hormone concentrations persist for at least 4-5 hours.

Signs and Symptoms of Overdose

The dopamine D₂ receptor is a 7-transmembrane G-protein coupled receptor associated with G_i proteins. In lactotrophs, stimulation of dopamine D₂ receptor causes inhibition of adenylyl cyclase, which decreases intracellular cAMP concentrations and blocks IP3-dependent release of Ca²⁺ from intracellular stores. Decreases in intracellular calcium levels may also be brought about via inhibition of calcium influx through voltage-gated calcium channels, rather than via inhibition of adenylyl cyclase. Additionally, receptor activation blocks phosphorylation of p42/p44 MAPK and decreases MAPK/ERK kinase phosphorylation. Inhibition of MAPK appears to be mediated by c-Raf and B-Raf-dependent inhibition of MAPK/ERK kinase. Dopamine-stimulated growth hormone release from the pituitary gland is mediated by a decrease in intracellular calcium influx through voltage-gated calcium channels rather than via adenylyl cyclase inhibition. Stimulation of dopamine D₂ receptors in the nigrostriatal pathway leads to improvements in coordinated muscle activity in those with movement disorders. Ergoline alkaloids have been shown to have the significant affinity towards the 5-HT1 and 5-HT2 serotonin receptors, D1 and D2 dopamine receptors, and alpha-adrenergic receptors. This can result in a number of different effects, including vasoconstriction, convulsions, and hallucinations. Bromocriptine acts by directly stimulating the dopamine receptors in the corpus striatum. (A2914, A2915, A2916, A2941)

Side effects of bromocriptine include nausea, headache, dizziness, fatigue, lightheadedness, vomiting, abdominal cramps, nasal congestion, constipation, diarrhea and drowsiness. Convulsive ergotism can cause painful seizures and spasms, diarrhea, paresthesias, itching, headaches, nausea and vomiting. Usually the gastrointestinal effects precede the central nervous system effects. As well as seizures there can be hallucinations and mental effects including mania or psychosis. Gangrenous ergotism causes dry gangrene as a result of vasoconstriction induced in the more poorly vascularized distal structures, such as the fingers and toes. Symptoms include desquamation, weak periphery pulse, loss of peripheral sensation, edema and ultimately the death and loss of affected tissues. (L1920, L1827)

Drug-Induced Liver Injury Severity and Toxicity (DILIst)

bromocriptine

DILI Positive

Oral

DOI:10.1016/j.drudis.2019.09.022

Bromocriptine

0.1

0.2

The initial dosage of bromocriptine mesylate tablets in adults is one-half to one 2.5 mg scored tablet daily. An additional 2.5 mg tablet may be added to the treatment regimen as tolerated every 2-7 days until an optimal therapeutic response is achieved. The therapeutic dosage ranged from 2.5-15 mg daily in adults studied clinically.

Data used to generate the benchmarks include the following: Lowest Daily Dose (LDD): 2.5 mg/day, Lowest Therapeutic Dose (LTD): 0.03 mg/kg-day, and Screening Dose: 0.00001 mg/kg-day.

4-May-07

The dopamine D₂ receptor is a 7-transmembrane G-protein coupled receptor associated with G_i proteins. In lactotrophs, stimulation of dopamine D₂ receptor causes inhibition of adenylyl cyclase, which decreases intracellular cAMP concentrations and blocks IP3-dependent release of Ca²⁺ from intracellular stores. Decreases in intracellular calcium levels may also be brought about via inhibition of calcium influx through voltage-gated calcium channels, rather than via inhibition of adenylyl cyclase. Additionally, receptor activation blocks phosphorylation of p42/p44 MAPK and decreases MAPK/ERK kinase phosphorylation. Inhibition of MAPK appears to be mediated by c-Raf and B-Raf-dependent inhibition of MAPK/ERK kinase. Dopamine-stimulated growth hormone release from the pituitary gland is mediated by a decrease in intracellular calcium influx through voltage-gated calcium channels rather than via adenylyl cyclase inhibition. Stimulation of dopamine D₂ receptors in the nigrostriatal pathway leads to improvements in coordinated muscle activity in those with movement disorders.

Completely metabolized by the liver, primarily by hydrolysis of the amide bond to produce lysergic acid and a peptide fragment, both inactive and non-toxic. Bromocriptine is metabolized by cytochrome P450 3A4 and excreted primarily in the feces via biliary secretion.

Bromocriptine has known human metabolites that include 5-bromo-N-[2,10-dihydroxy-7-(2-methylpropyl)-5,8-dioxo-4-propan-2-yl-3-oxa-6,9-diazatricyclo[7.3.0.02,6]dodecan-4-yl]-7-methyl-6,6a,8,9-tetrahydro-4H-indolo[4,3-fg]quinoline-9-carboxamide and 5-bromo-N-[2,11-dihydroxy-7-(2-methylpropyl)-5,8-dioxo-4-propan-2-yl-3-oxa-6,9-diazatricyclo[7.3.0.02,6]dodecan-4-yl]-7-methyl-6,6a,8,9-tetrahydro-4H-indolo[4,3-fg]quinoline-9-carboxamide.

Completely metabolized by the liver, primarily by hydrolysis of the amide bond to produce lysergic acid and a peptide fragment, both inactive and non-toxic. Bromocriptine is metabolized by cytochrome P450 3A4 and excreted primarily in the feces via biliary secretion. Route of Elimination: Parent drug and metabolites are almost completely excreted via the liver, and only 6% eliminated via the kidney. Half Life: 2-8 hours

3A64E3G5ZO

BROMOCRIPTINE

Chemical Structure [CS] - Ergolines

Established Pharmacologic Class [EPC] - Ergot Derivative

Bromocriptine is an Ergot Derivative.

Agents used in the treatment of Parkinson's disease. The most commonly used drugs act on the dopaminergic system in the striatum and basal ganglia or are centrally acting muscarinic antagonists.

Chemical substances which inhibit the function of the endocrine glands, the biosynthesis of their secreted hormones, or the action of hormones upon their specific sites.

Drugs that bind to and activate dopamine receptors.

Approximately 28% of the oral dose is absorbed; however due to a substantial first pass effect, only 6% of the oral dose reaches the systemic circulation unchanged. Bromocriptine and its metabolites appear in the blood as early as 10 minutes following oral administration and peak plasma concentration are reached within 1-1.5 hours. Serum prolactin may be decreased within 2 hours or oral administration with a maximal effect achieved after 8 hours. Growth hormone concentrations in patients with acromegaly is reduced within 1-2 hours with a single oral dose of 2.5 mg and decreased growth hormone concentrations persist for at least 4-5 hours.

Parent drug and metabolites are almost completely excreted via the liver, and only 6% eliminated via the kidney.