What is a dystonic reaction
- Syndrome of sustained, often painful muscular spasms, producing repetitive, twisting movements, or abnormal postures
- Develop following antipsychotic exposure
An extra pyramidal SE
RFs dystonic reaction
- PMH + FH dystonia
- Younger age
- Liver failure
- Severe schizophrenia
- Use of high-potency antipsychotics…etc
When does acute dystonia happen
Occurs w/in 1w o commencing or rapidly ↑ antipsychotic
What are the symptoms and signs of acute dystonia
o Muscles of head + neck: torticollis, trismus, jaw opening, forceful posturing of tongue, blepharospasm, grimacing, oculogyric spasm (eyes rolled back in locked position), opisthotonus
o Laryngospasm
o Dysphasia
What is tardive dystonia
Similar to acute but occurs days-months following exposure
Treatment for dystonia
- If severe: STOP antipsychotic
- Emergency Rx w/ IM anticholinergic (e.g. benzatropine)
- Consider switching to antipsychotic w/ low risk to cause EPSE (atypical antipsychotics)
What is neuroleptic malignant syndrome
TOO LITTLE DOPA
- Rare life-threatening condition in pt’s taking anti-psychotic medications
- May also occur in pt’s taking dopaminergic drugs (levodopa) in PD → when the drug is stopped or dose reduced*
*remember PD and schizophrenia are opposites on a spectrum (+ their treatments)
Aetiology neuroleptic malignant syndrome
- Overtreatment w/ antipsychotics (e.g. increasing dose)
- Stopping or reducing levodopa too quickly
- other drug causes: parkinson’s drugs can cause it too (as well as being withdrawn – e.g. amantadine), antidepressants (e.g. venlafaxine), carbamazepine…etc
CFs neuroleptic malignant syndrome
- Onset usually 10d of treatment or after ↑ dose
- Pyrexia/fever, muscular rigidity, confusion, fluctuating consciousness
- Autonomic dysfunction (as dopamine is a catecholamine): tachycardia, hypo/hypertension
ix neuroleptic malignant syndrome
- Creatinine kinase ↑
- FBC: leucocytosis (excess WBC)
- LFTs deranged
Rx neuroleptic malignant syndrome
- Stop antipsychotic/causative agent, monitor vital signs, IV fluids to prevent renal failure, cooling, dantrolene (muscle relaxant), bromocriptine (dopamine agonist)
- Consider: BDZ’s
- In parkinson’s to prevent neuroleptic malignant syndrome: slowly reduce PD dose if necessary (+ educate pt’s not to stop medications)
- Rhabdomyolysis: hydration + alkalinisation w/ IV sodium bicarbonate (prevent renal failure)
Complications neuroleptic malignant syndrome
- PE
- Renal failure
- Shock (due to low BP)
- Rhabdomyolysis
How does rhabdomyolysis cause renal failure?
it causes myoglobin release → breakdown → products damage kidney cells
Define serotonin syndrome
Rare life-threatening complication of increased serotonin activity (e.g. w/ SSRI use)
Aetiology serotonin syndrome
- SSRI
- Amfetamines
- MAOIs
- TCAs
- Lithium
Caused by overdose, drug combinations (e.g. over-the-counter) and therapeutic doses (rare)
Pathophysiology serotonin syndrome
- ↑ production serotonin
- ↑ release of stored serotonin: e.g. MDMA, cocaine…etc
- Reuptake inhibition (build up of serotonin): SSRIs, TCAs, SNRIs, MDMA…etc
- ↓ metabolism of serotonin: MAOIs, selegiline (MAOB-inhibitor used in parkinson’s)
CFs serotonin syndrome
- Psychiatric/neurological: agitation, confusion, hypomania, coma
- Neuromuscular: myoclonus (twitches), rigidity, tremor + shiver, hyperrefleia, ataxia
- Autonomic: hyperthermia/fever, GI upset (Diarrhoea), mydriasis, tachycardia, hyper/hypotension, sweating
Think MDMA
DDx serotonin syndrome
• Infection (e.g. encephalitis), metabolic disturbance, substance abuse/withdrawal
Ix serotonin syndrome
- FBC, U+Es, LFTs, glucose, pH, biochem (calcium, magnesium, phosphate, anion gap)
- CK (rhabdomyolysis)
- drug toxicology screen
- CXR (resp distress/aspiration)
- ECG monitioring → prolonged QRS or QTc interval
Rx serotonin syndrome
- STOP causative agent
- If OD: gastric lavage ± activated charcoal
- IV access + fluids: correct dehydration + prevent rhabdomyolysis
- BDZ: agitation, seizures…etc
- Serotonin receptor antagonist (chlorpromazine or propranolol)
- Antihypertensive (IV GTN) if persistent HTN
Complications serotonin syndrome
• Rhabdomyolysis
To summarise, serious consequences of antipsychotics are:
dystonic reactions + Neuroleptic malignant syndrome
To summarise, serious consequences of SSRIs are:
serotonin syndrome
Difference between Neuroleptic malignant syndrome and serotonin syndrome w/r to: Assoc. rx
NME: antipsychotics
SS: serotonergic
