Download pharmalogical emergencies

Pharmacological emergencies
Jacob Alexander
February 2016
TAPPP
Range of side effects from
commonly prescribed medication
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Medication Induced Movement Disorders
Serotonergic Syndrome
Drug Induced Weight Gain
Drug induced dysphoria, negative
syndrome like symptoms
• Drug related anticholinergic side effects
• Drug induced cardiac complication- QTc
prolongation
Medication
Induced
Movement
Disorders
Extra pyramidal system
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Anatomical
Neural Network that is part of the
motor system
Reticular formation of the pons and
the medulla
Nigrostriatal pathway
Basal Ganglia
Cerebellum
Cerebral cortex- motor and sensory
areas
Functional
Causes involuntary reflexes and
movements
Locomotion
Complex movements
Postural control
Extrapyramidal Tracts
Extrapyramidal
Tract
Extrapyramidal Side Effects
(EPSEs)
• The first generation (conventional) antipsychotics
may cause significant extrapyramidal side effects,
more so than the second generation antipsychotic
agents.
• Risperidone and Ziprasidone more likely to cause
EPSEs amongst second generation antipsychotic
agents
• EPSEs require careful assessment and
management
Objectives
Objectives
• Early Identification
• Encourage and alleviate anxiety for patient
and carers
• Be able to explain causes
• Be able to explain treatments
• Be able to choose/ prescribe treatment
options
Types of EPSEs
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Dystonia
Parkinsonism
Akathisia
Tardive Dyskinesia
Acetylcholine-Dopamine dysregulation
syndromes
EPSEs time to onset
Immediately after
use
48 hours from
initiation of drug
or increase in
dose
3 weeks from
initiation of drug
or increase in
dose
6 months or
more of use
Hypersensitivity
reactions
Dystonia
Parkinsonian
symptoms
Tardive dyskinesia
/ dystonia/
akathisia
Akathisia
Dystonia
• Occurs usually within 48 hours of initiation
of the medication
• Involves bizarre and severe muscle
contractions
• Can be painful and frightening
• Characterized by odd posturing and
strange facial expressions
Drug-induced Parkinsonism
• Usually occurs after 3 or more weeks of
treatment
• Characterized by:
– Cogwheeling rigidity
– Tremors
– Rhythmic oscillations of the extremities
– Pill rolling movement of the fingers
Akathisia
• Usually occurs after 3 or more weeks of
treatment
• Subjectively experienced as desire or need to
move
• Described as feeling like jumping out of the
skin
• Mild: a vague feeling of apprehension or
irritability
• Severe: an inability to sit still, resulting in
rocking, running, or agitated dancing
Tardive Dyskinesia
Dyskinesia
Tardive
• Usually occurs late in the course of longterm treatment
• Characterized by abnormal involuntary
movements (lip smacking, tongue
protrusion, foot tapping)
• Often irreversible
Complications
of
Tardive
Complications of Tardive Dyskinesia
Dyskinesia
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Inability to wear dentures
Impaired respirations
Weight loss
Impaired gait
Impaired posture
Dopamine-Acetylcholine Imbalance
in the Extrapyramidal System
• A rare side effect
• Characterized by hallucinations, dry
mouth, blurred vision, decreased
absorption of antipsychotics, decreased
gastric motility, tachycardia, and urinary
retention
• Neuroleptic Malignant Syndrome
Methods to Improve Assessment
of EPSEs
• Use rating scales.
– AIMS
– Simpson Neurological Rating Scale
• Videotape the exam for comparison at a
later date
Treatment
Treatment
of EPSEs
• Titrate dose
• Switch to AP less likely to cause extrapyramidal side-effects
• Evaluate need for EPSE causing other
meds- metaclorpromide, amoxapine,
SSRIs
• Anticholinergic agents- benztropine,
trihexyphenidyl, benadryl
• Akathisia- benzodiazepines and beta
blockers
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http://youtu.be/pSXzuCNlI6Q akathisia
http://youtu.be/2krwEbm5hBo dystonia
http://youtu.be/_s1lzxHRO4U catatonia
http://youtu.be/FUr8ltXh1Pc tardive
dyskinesia
• http://youtu.be/j86omOwx0Hk
parkinsonism
Serotonergic Syndrome
Drugs implicated in severe serotonin
syndrome
Drugs
Mechanism
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L-tryptophan
SSRIs
TCAs
MOAIs
Pethidine
Tramadol
LSD
Buspirone
Amphetamines and anorectics
Atypical Antidepressant
St John’s wort
Lithium
Serotonin precursor
Inhibits serotonin reuptake
Inhibits serotonin reuptake
Inhibit Metabolism of 5-HT
Serotonin agonist
Inhibits serotonin reuptake
Partial serotonin agonist
Partial serotonin agonist
Increased 5_HT release and
decreased reuptake
10. Various
11. All of the above?
12. Unknown
Clinical features of serotonin syndrome
• Cognitive
Confusion, agitation, hypomania,
hyperactivity, restlessness
• Autonomic
Hyperthermia, sweating, tachycardia,
hypertension, mydriasis, flushing, shivering
• Neuromuscular
Clonus(spontaneous/inducible/ocular),
hyperreflexia, hypertonia, ataxia, tremor
Hypertonia and clonus are always symmetrical and are often much
more dramatic in the lower limbs
Sternbach Criteria
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Mental state changes (confusion, hypomania)
Agitation
Myoclonus
Hyperreflexia
Diaphoresis
Shivering
Tremor
Diarrhoea
Inco-ordination
Fever
Hunter Serotonin Toxicity Criteria
Treatment
• Cessation of offending agent
• Mild to moderate – resolves
spontaneously in 24-72 hours
• Supportive care , temperature
management, benzodiazepines
• In severe cases- cyproheptadine,
propranolol, chlorpromazine
Dealing with drug induced QTc prolongation
QTc
<400 ms (men)
<470 ms
(women)
<400 ms (men)
<400 ms (men)
>500 ms (men or
women)
No action
required, referral
to cardiologist
based on specific
concerns
Consider:
Dose reduction
Medication
change
Repeat ECG
Cardiology
referral?
Stop suspected
causative agent
and switch to
alternative that is
less cardio
offensive
Refer to
cardiologist as a
matter of priority
Abnormal T Wave Morphology- review treatment: reduce dose, switch to drug
of lower effect, cardiologist referral