Drug Induced Parkinson disease
Related Subjects:Multiple System Atrophy (MSA)
|Parkinson Plus syndromes
|Parkinsonism
|Idiopathic Parkinson disease
|Progressive Supranuclear Palsy
|Drug Induced Parkinson disease
โ ๏ธ High risk with dopamine D2-receptor blocking agents (e.g. haloperidol).
๐ Can also occur with commonly used drugs such as metoclopramide.
๐ Most effective treatment = stop or reduce the offending drug under medical supervision.
๐ About
- History of dopamine-blocking drug use (antipsychotics, antiemetics).
- Seen in ~7% of patients with parkinsonian features.
๐งฌ Aetiology
- Dopamine receptor blockers.
- Peripheral agents: antiemetics (e.g. metoclopramide, prochlorperazine).
- Central agents: neuroleptics (e.g. haloperidol, chlorpromazine).
๐ Causative Drugs
- Antiemetics: Prochlorperazine (Stemetil), Metoclopramide.
- Psychotropics: Lithium, Sodium valproate, Tetrabenazine, Reserpine, ฮฑ-methyldopa.
- Cardiovascular: Diltiazem, Captopril, Calcium channel blockers.
- Oncology/other: Thalidomide, Cytarabine, Ifosfamide, Vincristine, Tamoxifen.
- Toxins: MPTP (synthetic opioid contaminant, classic cause of parkinsonism).
๐ฅ Risk Groups
- ๐ต Elderly
- โ๏ธ Female sex
- ๐งฌ Preclinical idiopathic PD
- ๐งโโ๏ธ High-dose dopamine blockers
- Patients with tardive dyskinesia
- Individuals with AIDS
๐ฉบ Clinical Features
- Subacute, symmetrical onset of parkinsonian symptoms.
- Postural tremor (early).
- Bradykinesia, akinesia.
- Oralโbuccal dyskinesias often co-present.
- Clear history of recent dopamine-blocking drug use.
๐งพ Differentials
- Idiopathic Parkinsonโs disease (PD) - key to differentiate (DIP usually symmetrical, PD often asymmetrical with rest tremor).
๐ Investigations
- CT/MRI brain if diagnosis unclear or to exclude structural pathology.
- Note: DAT-SPECT can sometimes help differentiate DIP from idiopathic PD (DIP usually normal).
โ๏ธ Management
- ๐ Early recognition is crucial.
- ๐ซ Stop or switch the offending drug (most remit within 4 months).
- ๐ Consider anticholinergics (e.g. procyclidine) but beware delirium/confusion, especially in elderly.
- ๐ Amantadine may be useful in persistent cases.
- โ
If antiemetic needed, switch to domperidone or ondansetron (minimal CNS penetration).
- Antipsychotic alternatives: olanzapine, risperidone (lower risk, but not risk-free).
๐ References
