Dystonic reaction
Background
- adverse extrapyramidal effect (intermittent spasmodic or sustained involuntary contractions of muscles) that occurs shortly after initiation of new drugs
- rarely life threatening but patient is in distress from pain and discomfort
- men are affected more frequently than women
- predisposing factors:
- young age
- family history of dystonic reaction
- history of EtOH or drug use
- associated with administration of antiemetics or antipsychotic medications
- 25% of patients treated with Haldol have been known to develop this reaction
- reaction usually occurs within 48 hrs of drug treatment but can occur up to 5 days after starting therapy
- severity and onset of reaction depends on an individual, no association with dose, drug type, potency of drug, or duration of treatment
- many theories on what causes the reaction
- direct blockade of central dopaminergic receptors
- imbalance of neurotransmitters (dopamine and acetylcholine) causing excessive cholinergic activity
- combination of dopamine blockade initially by the offending agent and later dopamine activation in nigrostriatal system
Diagnosis
- History of recent drug exposure or increase in drug dosage
- Thorough drug history (prescription, over the counter, herbals, illegal)
- Physical exam is usually normal except for dystonia of any striated muscle group. Some common presentations include:
- torticollar reaction
- buccolingual reaction
- oculogyric crisis
- oromandibular dystonia
- lingual dystonia
- kyphosis/lordosis/scoliosis
- trismus
- facial grimacing
- tortipelvic crisis
==Medications Associated with Dystonic Reaction==
- Amitriptyline
- Amoxaine
- Azatadine
- Buproprion
- Chlorpromazine
- Chlorprothixene
- Cimetiddine
- Cisapride
- Cocaine
- Clomipramine
- Clozapine
- Cyclizine
- Dexgtromethorphan
- Diazepam
- Diphenhydramine
- Doxepin
- Etomidate
- Fluoxetine
- Fluphenazine
- Fluvoxamine
- Haloperidol
- Imipramine
- Ketamine
- Lozapine
- Mesoridazine
- Methohexital
- Metoclopraminde
- Olanzpine
- Paroxetine
- Perphenazine
- Phenelzine
- Pheyntoin
- Pimozide
- Prochlorperazine
- Promazine
- Promethazine
- Propofol
- Quietiapine
- ranitidine
- Risperidone
- Sertraline
- Thiethylperazine
- Thiopental
- Thioridazine
- Thiothixene
- Tigabine
- tranylcypromine
- Trifluoperazine
- Triflupromazine
Work-Up
- consider Utox if no offending agent given by history
==DDx==
- tetanus
- hysterical conversion disorder
- dislocation of mandible
- electrolyte abnormality (Calcium, magnesium)
- meningitis
- seizure disorder
- strychnine poisoning
- akathisia
- stroke
- drug toxicity (anticholinergic, phenytoin, valproate, carbamazepine)
==Treatment==
- Anticholinergic medication:
- Diphenhydramine: 50-100mg over 2 minutes
- Benztropine: 1-2 mg in adults over 2 minutes
- Biperiden
- Trihexyphenidyl 2mg PO BID
- IV > IM > PO
- symptoms will typically begin resolving in 2-15 minutes but may take up to 90 minutes to completely abate (depends on route in which medication was given)
- patients may require more than one dose of IV medication before symptoms resolve completely
- Benzodiazepines
- Airway Management
- rare, but may be indicated in patients with severe respiratory distress from laryngeal or pharyngeal dystoni
==Disposition==
- stop the offending agent (if antipsychotic, speak with patients psychiatrist before just stopping the medication)
- continue to treat with PO anticholinergic to prevent relapse of symptoms
- Diphenhydramine: 12.5-50mg PO TID-QID
- Benztropine: 1-2mg PO BID
Source
Adapted from Harwood-Nuss
emedicine