Side Effects of Parlodel (bromocriptine)

Parlodel (bromocriptine) is an anticholinergic used to treat hyperprolactinemia, acromegaly, and symptoms of Parkinson’s disease.

Parlodel treats symptoms of Parkinson’s disease or involuntary movements caused by psychiatric drugs. It works by blocking acetylcholine, reducing muscle stiffness, sweating, and saliva production, and improving walking ability.

Parlodel can stop severe muscle spasms of the back, neck, and eyes caused by psychiatric drugs and reduce side effects like muscle stiffness/rigidity.

Common side effects include:

• low blood pressure (hypotension),
• dizziness or lightheadedness on standing (orthostatic hypotension),
• sleepiness,
• drowsiness.

Serious side effects include worsening psychotic symptoms or reduced effectiveness of medications used to treat psychotic disorders.

Parlodel can interact with certain medications used to treat schizophrenia and other mental disorders, drugs that increase or decrease the activity of CYP3A4 enzymes, and ergot related drugs used to treat migraines.

There are no adequate and well-controlled studies of Parlodel use in pregnant women. It should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.

Breastfeeding mothers should not use Parlodel as it reduces production of breast milk.

Important Side Effects of Parlodel (bromocriptine)

WARNING

• Low blood pressure (hypotension) has been reported in some patients taking bromocriptine. Be cautious when starting treatment or increasing dose to avoid falls.
• Patients with pre-existing mental disorders may experience worsening psychotic symptoms or reduced effectiveness of medications used to treat psychotic disorders.
• Bromocriptine may cause sleepiness or drowsiness. Do not drive or operate machinery until you know how it affects you.
• Some medications used to treat schizophrenia and other mental disorders may interact with bromocriptine.

Parlodel (bromocriptine) Side Effects for Healthcare Professionals

Adverse Reactions from Clinical Trials

Hyperprolactinemic Indications

• The incidence of adverse effects is quite high (69%), but generally mild to moderate.
• Approximately 5% of patients discontinued therapy due to adverse effects.
• The most frequent adverse effects are nausea (49%), headache (19%), dizziness (17%), fatigue (7%), lightheadedness (5%), vomiting (5%), abdominal cramps (4%), nasal congestion (3%), constipation (3%), diarrhea (3%), and drowsiness (3%).

Acromegaly

• The most frequent adverse reactions in acromegalic patients treated with Parlodel are nausea (18%), constipation (14%), postural/orthostatic hypotension (6%), anorexia (4%), dry mouth/nasal stuffiness (4%), indigestion/dyspepsia (4%), digital vasospasm (3%), drowsiness/tiredness (3%), and vomiting (2%).
• Other adverse reactions include gastrointestinal bleeding, dizziness, Raynaud’s syndrome exacerbation, headache, and syncope.

Parkinson’s Disease

• In clinical trials with concomitant levodopa/carbidopa reduction, newly appearing adverse reactions include nausea, abnormal involuntary movements, hallucinations, confusion, “on-off” phenomenon, dizziness, drowsiness, faintness/fainting, vomiting, asthenia, abdominal discomfort, visual disturbance, ataxia, insomnia, depression, hypotension, shortness of breath, constipation, and vertigo.
• Other adverse reactions include anorexia, anxiety, blepharospasm, dry mouth, dysphagia, edema of the feet and ankles, erythromelalgia, epileptiform seizure, fatigue, headache, lethargy, mottling of skin, nasal stuffiness, nervousness, nightmares, paresthesia, skin rash, urinary frequency, urinary incontinence, urinary retention, and signs and symptoms of ergotism (tingling of fingers, cold feet, numbness, muscle cramps, exacerbation of Raynaud’s syndrome).

Adverse Reactions from Postmarketing Experience

Adverse reactions reported during postapproval use of Parlodel include:

• Psychiatric disorders: Confusion, psychomotor agitation/excitation, hallucinations, psychotic disorders, insomnia, increased libido, hypersexuality.
• Nervous system disorders: Headache, drowsiness, dizziness, dyskinesia, somnolence, paraesthesia, excess daytime somnolence, sudden onset of sleep.
• Eye disorders: Visual disturbance, blurred vision.
• Ear and labyrinth disorders: Tinnitus.
• Cardiac disorders: Pericardial effusion, constrictive pericarditis, tachycardia, bradycardia, arrhythmia, cardiac valve fibrosis.
• Vascular disorders: Hypotension, orthostatic hypotension leading to syncope, reversible pallor of fingers and toes induced by cold.
• Respiratory, thoracic and mediastinal disorders: Nasal congestion, pleural effusion, pleural fibrosis, pleurisy, pulmonary fibrosis, dyspnea.
• Gastrointestinal disorders: Nausea, constipation, vomiting, dry mouth, diarrhea, abdominal pain, retroperitoneal fibrosis, gastrointestinal ulcer, gastrointestinal hemorrhage.
• Skin and subcutaneous tissue disorders: Allergic skin reactions, hair loss.
• Musculoskeletal and connective tissue disorders: Leg cramps.
• General disorders and administration site conditions: Fatigue, peripheral edema, Neuroleptic Malignant Syndrome-like syndrome on abrupt withdrawal of Parlodel.

Adverse Events Observed in Other Conditions

Postpartum Patients

• Approximately 23% of postpartum patients treated had at least 1 side effect, generally mild to moderate.
• Approximately 3% of patients discontinued therapy.
• The most frequently occurring adverse reactions were headache (10%), dizziness (8%), nausea (7%), vomiting (3%), fatigue (1.0%), syncope (0.7%), diarrhea (0.4%), and cramps (0.4%).

Drug Interactions with Parlodel (bromocriptine)

• The risk of using Parlodel in combination with other drugs has not been systematically evaluated, but alcohol may potentiate its side effects.
• Parlodel may interact with dopamine antagonists, butyrophenones, and certain other agents.
• Compounds in these categories result in decreased efficacy of Parlodel, including phenothiazines, haloperidol, metoclopramide, and pimozide.

Summary

Parlodel (bromocriptine) is an anticholinergic used to treat hyperprolactinemia, acromegaly, and symptoms of Parkinson’s disease. Common side effects include low blood pressure (hypotension), dizziness or lightheadedness on standing (orthostatic hypotension), sleepiness, and drowsiness. There are no adequate and well-controlled studies of Parlodel use in pregnant women. Parlodel should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Breastfeeding mothers should not use Parlodel because it reduces production of breast milk.