Psychiatric drug induced syndromes

Dr Jason Ward

Acute Dystonia

• Sustained abnormal postures or muscle spasms that develop within 7 days of starting antipsychotic medication

• 95% cases within 96 hours

• Pathogenesis unclear – possibly D2 receptor blockade in caudate,

putamen & globus pallidus

Risk factors

• Young age

• Male

• Previous episode

• Recent cocaine use

• ? Race

• ? Presence of affective disorder

• Dehydration, hypocalcaemia, hypoparathyroidism

Clinical Features

• Any muscle group

• Head & neck common

• Torticollis

• Trismus

• Grimacing

• Dysarthria

• Blepharospasm

• Swallowing difficulties

• Oculogyric crisis *• Opisthotonus• Laryngospasm &

stridor

* Can occur on stable dose

Differential Diagnosis

• Psychogenic dystonia

• Catatonia - mutism, akinesis, rigidity

• Tardive dystonia - months after treatment

• Hypocalcaemia

• Temporal epilepsy

Drug causes

• Antipsychotics

• Antiemetics

• Antidepressants - SSRIs

• Case reports of others– carbemazepine, phenytoin, diazepam

Treatment

• Anticholinergic im – procyclidine 5mg, usually effective 20mins– occasionally 2nd/3rd dose

• Or antihistamine – promethazoine 50mg

• Oculogyric crisis - can add clonazepam

• Continue for 4-7 days

Serotonin Syndrome

• Syndrome of rigidity, myoclonus, hyperreflexia, nausea & vomiting, autonomic instability, hyperthermia confusion, agitation, delirium, coma

• Aetiology excess 5-HT ? 5-HT1A

• Unknown incidence

Drug causes

• SSRI with MAOI

• High dose SSRIs

• Combination of SSRIs

• St John’s Wort + antidepressant

• Also MAOI + pethidine, dextromethorphan

Treatment

• Stop drug - usually settles in 24 hours

• Cooling

• Fluids if hypotensive

• Clonazepam for myoclonus

• ? Cyproheptadine ? Propranolol ?methysergide

Neuroleptic Malignant Syndrome

• Severe muscle rigidity and elevated temperature in an individual using neuroleptic medication

• Accompanied by >2– sweating, dysphagia, tremor, incontinence,

mutism, tachycardia, labile BP, change in level of consciousness, elevated WCC/CPK

Risk Factors

• Prior episode

• Dehydration, warm ambient temperature

• High potency neuroleptic or rapid rise in dose

• im injection

• Male:Female 2:1

• All ages (45% 20-39)

• 90% within first 10 days of treatment

Treatment

• Stop neuroleptics

• Control fever

• Fluid balance

• Benzodiazepines

• ? Bromocriptine ? Dantrolene

• Re-challenge with neuroleptic after 2 weeks

ReferencesVan Harten PN, Hoek HW, Kahn RS. Acute dystonia inducedby drug treatment. BMJ 1999;319:623-6

Sternbach H. The Serotonin Syndrome. Am J Psychiatry 1991;148:705-713

Bristow MF, Kohen D. How malignant is the neuroleptic malignant syndrome? BMJ 1993;307:1223-4

Carbone JR. The neuroleptic malignant and serontonin syndromes. Emer Med Clin N America 2000;18:317-25