Antipsychotics & Antidepressants Flashcards
EXTRAPYRAMIDAL symptoms:
From antidopamines:
- Antipsych (typicals)
- Metoclopr, stemetil
- SSRI, SNRI
ACUTE DYSTONIC REACTION
- Painful spasms
- Torticollis
- Oculogyric crisis (upward deviation)
AKISTHESIA
- Restless, fidgety
PseudoPARKINSONISM
- Bradykinesia, rigidity, tremor, shuffling
_____________
TARDITIVE DYSKINESIA (chronic)
- Tongue protrusion, blinking, lip smacking, grimacing
NEUROLEPTIC MALIGNANT SYNDROME:
- Idiosyncratic (2.5%)
- Mortality 10%
It’s all about…. DOPAMINE!
1- Antidopamine:
(antipsych, stemetil, metoclop)
2- Withdrawal from dopaminergics: (Parky meds)
INSIDIOUS onset- days/weeks
- Hyperthermia
- Rigidity (lead pipe) with hyporeflexia
- Negatively altered mental state (mutism, staring, bradykinesia)
- Rhabdo
- Autonomic dysfunction
Recovery multiple days to months
Risk factors for NEUROLEPTIC MALIGNANT SYNDROME:
-Multiple drug, high dose, uptitration
- Old school antipsychs (partic haloperidol)
- ABRUPT CESSATION OF PARKINSON MEDS
- Dehydration
- Exhaustion or intercurrent illness
- Young, male
But ultimately, IDIOSYNCRATIC.
Management of NEUROLEPTIC MALIGNANT SYNDROME:
Cease causative agent/s
MILD:
- BZD
SEVERE:
- Intubate and paralyse
- BROMOCRIPTINE for autonomics
—> 2.5mg PO, double dose and freq. up to 30mg/day.
- DANTROLENE for rigidity/fever
—> 2-10 mg/kg/day
- HTN Mx
- Rhabdo Mx
ECTmay improve fever, sweating, ALOC and residual catatonia)
Observe 12 hours
Recurrence of in 30-50%
Differential for ‘hot and stiff’
Serotonin syndrome
NMS
Anticholinergic syndrome
Malignant hyperthermia
Salicylate toxicity
Wernicke’s
CNS infections (with opisthotonos)
Malignant catatonia
Tonic status
Tetanus
Heat stroke
TRICYCLIC (TCA) OD:
- Amitriptyline
- Nortriptyline
- Doxepin
R
- Usual
R
- <5mg/kg benign
- 5-10: drowsy, mild anticholinergic
- >10mg/kg life-threatening
- Kids: “one pill can kill”.
S
ANTICIPATE:
Within 1-2 hours:
- Coma, seizure
- Arrhythmia
- HypoTN
- + Anticholinergic
—> Anticholinergic + Na channel blockade = TCA
-SUPPORT:
Get serum PH 7.5 - 7.55 via HYPERVENTILATION and SODI BIC
I
- 12-lead, BGL, parac (delib)
SERIAL ECG
–> Broad, terminal R wave aVR etc.
–> QRS >100ms = seizure likely
–> QRS >160ms = VT likely
MANAGEMENT:
- Bicarb ASAP. 2mmol/kg every 5 mins until serum pH 7.5/ stable
- Intubate early. HYPERventilate through induction and once tubed
—> can often stop bicarb at this point.
- Once tubed, 50g activated charcoal
- Treat seizure with BZD
- If ventricular arrhythmia persists once pH at 7.5
—> DCR likely futile
—> Ligocaine is only med option 1.5mg/kg
D
Prolonged resus. Not at end until pH target met.
OBSERVE 6 hours
Role of LIGNOCAINE in TCA OD:
ONLY antiarrhythmic that can be tried (if refractory despite pH target)
Seems counterintuitive, but:
- Competitively inhibits TCA
- Doesn’t prolong QTc
1a antiarrythmics will WORSEN the Na blockade (broad) and K+ blocked (prolonged QT) effects of TCAs. Others (BB, CCB) will worsen hypoTN and conduction.
ECG in Na channel blockade:
- Sinus tachy (if TCA) (brady if propanolol!)
-
Broad QRS
–> >100ms = seizure risk
–> >160ms = VT risk - Terminal R wave (>3mm) aVR or RS ratio >0.7 (70% size of S)
Describe a terminal R wave (aVR):
- Dominant (typically avR is DOWN)
- Tall (>3mm)
- Broad and slurred
Which drugs will cause a Na channel blockade on ECG:
TCA (tachy)
Flecainide
Propanolol (brady)
Carbamazepine
Local anaesthetics
Cocaine
Phenytoin
Dexyproxyphene (Digesic)
Antimalarials (quinine, chloroquine)
VENLAFAXINE OD
SNRI
R
- Usual
R
- >12.5mg/kg significant
- Seizure risk is dose-related
S
ANTICIPATE:
- DELAYED SEIZURE (16 hours)
- Serotonin syndrome (if other meds)
- Cardiogenic shock (if massive >7g)
- Rhabdo (rare)
SUPPORT:
- All supportive Mx.
I
- 12-lead, BGL, parac (delib)
D
AC: yes consider
E
No
A
No
D
VA ECMO
OBSERVE 16 hours
COMA IS NOT A FEATURE- something else going on…
MAOI OD:
R
- Usual
R
- Moclobenide benign in isolation
- Phenelzine and Tranylcypromine bad
- Kids: “One pill can kill” (not moclob)
(Tyramine reaction: cheese + MAOI = malignant HTN)
S
ANTICIPATE:
AT 6-12 hours:
- SEROTONIN and SYMPATHOMIMETIC syndromes
-SUPPORT:
As per syndromes:
- BZD, BZD, BZD
- Consider phentolamine, NO BB.
I
- 12-lead, BGL, parac (delib)
- CK, myoglobin, trop, +/- CXR, CTB etc.
D
AC: Yes (not moclob)
E
No
A
Cyproheptidine as per SS
D
OBSERVE 12 hours
MIRTAZEPINE OD
- Benign incl children (accidental = no ED)
- Drowsy + tachycardic about as bad as it gets
- Observe 4 hours
SSRI OD:
- Citalopram, escitalopram, fluoxetine, sertraline
Benign, incl children (accidental - no ED)
May get:
–> Mild serotonin syndrome
CITALO /ESCITALO:
–> Mild QT prolongation
–> Seizure (rare)
All of these self-limiting and don’t lead to much.
Observe 8-12 hours.
ANTIPSYCHOTIC OD:
Sedation –> coma
Anticholinergic
Quetiapine
–> Mild QT prolongation
–> Tachycardia
–> HypoTN
Olanzipine: retention
Risperidone: acute dystonia
Clozapine: hypersalivation
Supportive care: good outcomes.
BENZTROPINE 1-2mg IV if dystonia.
Delayed EPS (3 days)
Observe 4-8 hours.
