Definition:
- Dopamine agonists are medications that mimic the effects of dopamine by binding to dopamine receptors in the brain.
Clinical Indications:
- Parkinson’s Disease: Mainstay treatment for motor symptoms including bradykinesia, rigidity, and tremors.
- Restless Legs Syndrome (RLS): Alleviate uncomfortable sensations and urge to move.
- Hyperprolactinemia: Inhibit prolactin secretion from the pituitary gland, useful in treating hyperprolactinemia and related conditions.
Types of Dopamine Agonists:
- Ergot Derivatives:
- Examples: Bromocriptine, Cabergoline.
- Often used in Parkinson’s disease and hyperprolactinemia.
- Non-Ergot Derivatives:
- Examples: Pramipexole, Ropinirole, Rotigotine.
- Commonly prescribed for Parkinson’s disease and restless legs syndrome.
- Non-Selective Agonists:
- Example: Apomorphine.
- Used as a rescue medication for “off” episodes in advanced Parkinson’s disease.
Mechanism of Action:
- Direct stimulation of dopamine receptors in the brain, modulating motor function, hormone regulation, and various physiological processes.
Adverse Effects:
- Nausea, vomiting, orthostatic hypotension, hallucinations, impulse control disorders, and dyskinesias.
- Rare but serious adverse events: Cardiac valvulopathy, pulmonary fibrosis.