Bromocriptine

Antiparkinsonian Drug

Drug class: Dopamine D2 Receptor Agonist

Bromocriptine (PARLODEL)（中文：溴隱亭）

Pronunciation

Bromocriptine 2.5mg

Common Strengths of Bromocriptine

• Tablet: 2.5 mg

Drug Trade Names

• Parlodel

Drug Usage

Bromocriptine is indicated for:

• Hyperprolactinemia: Conditions leading to excessive prolactin levels.
• Parkinson's Disease: To manage symptoms like stiffness and tremors.
• Acromegaly: To contorl growth hormone secretion.

Mechanism of Action

Bromocriptine acts as an agonist on dopamine D2 receptors, inhibiting prolactin secretion from the pituitary gland and alleviating symptoms associated with conditions like hyperprolactinemia and Parkinson's disease.

Route of Administration

Oral

Dosages

• Initial: 1.25-2.5 mg once daily.
• Maintenance: 5-15 mg/day, with some cases requiring up to 30 mg/day.

Side Effects

Frequency	Adverse reactions
Common Side Effects	Dizziness
	Nausea
	Headaches
Serious Side Effects	Hallucinations
	Severe hypotension
	Pulmonary fibrosis

Pharmacokinetics

• Bioavailability: Approximately 28% after oral administration.
• Half-life: 12-14 hours.
• Onset of Action: Varies; generally within hours for most effects, but full therapeutic effects may take longer.

Drug Precautions

Pregnancy

Bromocriptine may be acceptable during pregnancy, but caution is warranted, especially in women with high blood pressure.

Breastfeeding

Not recommended as it can inhibit lactation.

Children and Elderly

Dosage adjustments are often necessary; pediatric use is typically limited to ages 11-15 years.

Drug Monitoring Items

• Blood Pressure Monitoring: Patients should have their blood pressure monitored regularly. Orthostatic hypotension can occur, leading to dizziness or syncope.
• Liver Function Tests: Regular liver function test should be conducted to monitor for elevated liver enzymes.
• Pregnancy Testing: Women of childbearing age should undergo pregnancy testing if amenorrhea occurs while on bromocriptine, as the medication can suppress prolactin levels necessary for normal pregnancy.
• Cardiac Monitoring: A cardiovascular assessment is advised before starting bromocriptine, especially in patients with a history of cardiovascular disease. Close monitoring is necessary throughout treatment due to potential cardiac side effects like myocardial toxicity.
• Regular Eye Examinations: Patinets may require periodic eye exams if they are at risk for visual disturbances related to bromocriptine use.
• Monitoring for Impulse Control Disorders: Patients should be assessed for behavioral changes or impulse control issues, which can occur with dopamine agonists like bromocriptine.

Drug Interactions

Bromociptine may interact with:

• Dopamine Antagonists
  • Antipsychotics (e.g. clozapine, olanzapine): These can reduce the effectiveness of bromocriptine due to their dopamine-blocking properties. Concurrent use is not recommended.
• Sympathomimetics
  • Amphetamines and other sympathomimetic agents: Co-administration can lead to hypertension and tachycardia, particularly in postpartum women.
• Selective Serotonin Reuptake Inhibitors (SSRIs)
  • SSRIs may increase the risk of serotonin syndrome when combined with bromocriptine.
• Triptans (e.g. sumatriptan)
  • The combination can also lead to serotonin syndrome and is generally contraindicated.
• Benzodiazepines
  • Combining bromocriptine with benzodiazepines may increase the risk of CNS depression.
• Metformin
  • There may be an increased risk of hypoglycemia when bromocriptine is used alongside metformin.
• CYP3A4 inhibitors (e.g. erythromycin) which may increase bromocriptine levels.

FAQ

How Should I Take the Tablet?

Take bromocriptine orally with food to minimize gastrointestinal side effects.

What Should I Avoid While Taking?

Avoid activities that require alertness until you know how bromocriptine affects you; also, avoid alcohol and other CNS depressants.

What Happens if I Miss a Dose?

If you miss a dose, take it as soon as you remember unless it is almost time for your next dose. Do not double up on doses.