Is it safe to prescribe a stimulant to a patient with Huntington's disease?

Stimulant Use in Huntington's Disease

Prescribing stimulants to a 49-year-old male with Huntington's disease is potentially dangerous and should be avoided due to the risk of worsening choreoathetoid movements. 1

Risks of Stimulants in Huntington's Disease

Stimulant medications can exacerbate movement disorders in patients with Huntington's disease (HD) through the following mechanisms:

• Worsening of Chorea: There is documented evidence that psychostimulants like lisdexamfetamine can worsen choreoathetoid movements in HD patients 1
• Dopaminergic Effects: Stimulants increase dopamine levels, which can disrupt the already imbalanced neurotransmitter systems in the basal ganglia of HD patients 1
• Limited Therapeutic Benefit: There is no evidence supporting the use of stimulants for cognitive symptoms in HD 2

Contraindications to Consider

The American Academy of Child and Adolescent Psychiatry practice parameters highlight several contraindications that are relevant to HD patients:

• Psychosis: Stimulants can worsen psychotic symptoms, which may be present in HD 3
• Motor Disorders: Although not an absolute contraindication for all patients, stimulants require careful consideration in movement disorders 3
• Neurological Conditions: Patients with degenerative neurological illnesses require special caution with stimulants 3

Evidence of Harm

The most compelling evidence comes from a case report documenting:

• A 52-year-old man with HD experienced significant worsening of choreoathetoid movements while taking lisdexamfetamine 1
• Discontinuation of the stimulant resulted in improvement of the movement disorder 1
• The Naranjo adverse event score for lisdexamfetamine was 5, indicating a probable adverse drug reaction 1

Treatment Alternatives for HD Symptoms

Instead of stimulants, consider these evidence-based approaches for managing HD symptoms:

For Motor Symptoms

• Antipsychotics: Haloperidol or fluphenazine have some evidence for treating chorea 4
• Tetrabenazine: A dopamine-depleting agent that may help control involuntary movements 5

For Psychiatric/Behavioral Symptoms

• SSRIs: First-line for irritability and obsessive-compulsive behaviors, though fluoxetine should be used with caution as it may worsen chorea 2, 1
• Antipsychotics: Useful for both movement disorders and psychiatric symptoms 2

For Cognitive Symptoms

• Limited evidence for any effective treatments 2
• Acetylcholinesterase inhibitors have been tried but with minimal evidence 5

Monitoring Recommendations

If treatment with any medication is initiated for HD:

• Regularly assess all three clinical domains: motor, behavioral/psychiatric, and cognitive 2
• Adjust medications as the disease progresses 2
• Carefully evaluate the risk-benefit ratio on an individual basis 2

Conclusion

The available evidence strongly suggests avoiding stimulant medications in patients with Huntington's disease, particularly when choreoathetoid movements are present. The risk of worsening motor symptoms outweighs potential benefits, and alternative treatment approaches should be considered for managing the various symptoms of HD.