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Pharmacological emergencies. Jacob Alexander February 2016 TAPPP. Range of side effects from commonly prescribed medication. Medication Induced Movement Disorders Serotonergic Syndrome Drug Induced Weight Gain Drug induced dysphoria, negative syndrome like symptoms
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Pharmacological emergencies Jacob Alexander February 2016 TAPPP
Range of side effects from commonly prescribed medication • 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
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 Extra pyramidal system
Extrapyramidal Tract Extrapyramidal Tracts
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 Dystonia Parkinsonism Akathisia Tardive Dyskinesia Acetylcholine-Dopamine dysregulation syndromes
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 Tardive Dyskinesia Usually occurs late in the course of long-term treatment Characterized by abnormal involuntary movements (lip smacking, tongue protrusion, foot tapping) Often irreversible
Complications of Tardive Dyskinesia Complications of Tardive Dyskinesia Inability to wear dentures Impaired respirations Weight loss Impaired gait Impaired posture
Dopamine-Acetylcholine Imbalancein 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 Assessmentof 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 extra-pyramidal side-effects Evaluate need for EPSE causing other meds- metaclorpromide, amoxapine, SSRIs Anticholinergic agents- benztropine, trihexyphenidyl, benadryl Akathisia- benzodiazepines and beta blockers
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
Drugs implicated in severe serotonin syndrome Drugs Mechanism 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 Various All of the above? Unknown • L-tryptophan • SSRIs • TCAs • MOAIs • Pethidine • Tramadol • LSD • Buspirone • Amphetamines and anorectics • Atypical Antidepressant • St John’s wort • Lithium
Clinical features of serotonin syndrome Confusion, agitation, hypomania, hyperactivity, restlessness Hyperthermia, sweating, tachycardia, hypertension, mydriasis, flushing, shivering Clonus(spontaneous/inducible/ocular), hyperreflexia, hypertonia, ataxia, tremor Hypertonia and clonus are always symmetrical and are often much more dramatic in the lower limbs • Cognitive • Autonomic • Neuromuscular
Sternbach Criteria • 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