Oral Medications
There are many medications that have been shown to improve dystonia.
There are several categories of medications used in the treatment of dystonia. These categories include :
- Anticholinergics
- Benzodiazepines
- Baclofen
- Dopaminergic agents / Dopamine-depleting agents
- Tetrabenezine
Most of the medications used to treat dystonia work by affecting the neurotransmetter chemicals in the nervous system that execute the brain's instructions for muscle movement and the control of movement. Patients are started on a very low dose of medication and the dose is gradually increased until the benefits is fully realized and/or side effects warrant a lower dose.
Anticholinergics
Anticholinergics include such drugs as Artane® (trihexyphenidyl), Cogentin® (benztropine), or Parsitan® (ethopropazine) which block a neurotransmitter called acetylcholine. Use of these drugs is sometimes limited by central side effects such as confusion, drowsiness, hallucination, personality change, and memory difficulties, and peripheral side effects such as dry mouth, blurred vision, urinary retention, and constipation.
Benzodiazepines
Benzodiazepines, such as Valium® (diazepam), Klonopin® (clonazepam), and Ativan® (lorazepam) affect the nervous system's ability to process a neurotransmitter called GABA-A. A primary side effect is sedation, but others include depression, personality change, and drug addiction. Rapid discontinuation can result in a withdrawal syndrome. Some dystonia patients tolerate very high doses without apparent adverse effects.
Baclofen
Baclofen (Lioresal®) stimulates the body's ability to process a neurotransmitter called GABA-B. Intrathecal forms of baclofen, in which a steady dose of medication is fed into the nervous system by a surgically implant device, are also available. Side effects may include confusion, dizziness or lightheadedness, drowsiness, nausea, and muscle weakness.
Dopaminergic agents
Some patients with primary dystonia respond to drugs which increase the neurotransmitter dopamine. These drugs are called dopaminergic agents and include Sinemet® (levodopa) or Parlodel® (bromocriptine). Side effects may include parkinsonism, hypotension, and depression. Ironically, however, many patients respond to agents which block or deplete dopamine. Many of these drugs are such as antipsychotic agents like Clozaril® (clozapine), Nitoman® (tetrabenazine), or Reserpine®.
Tetrabenezine
Tetrabenezine is a drug that decreases dopamine and may help some patients. It is not generally available in the United States, but some physicians at major research centers are occasionally granted exemptions for use in the patients, particularly for research purposes.