Psych Drugs Short Notes.pdf

SSRI Examples • Fluoxetine • Paroxetine • Citalopram • Sertraline Indications • Depression • Anxiety • OCD • Bulimia nervosa (fluoxetine) Contraindication Mania Prescription Notes • Opposed to TCAs, SSRIs are alerting not sedating, so prescribe them for the morning • The only SSRI recommended in under 18s is fluoxetine Common Side Effects • Early side effects — increased anxiety (suicide risk in young people), GI disturbances • Loss of appetite and weight loss (sometimes weight gain) • Insomnia • Sweating • Sexual dysfunction (anorgasmia, delayed ejaculation)


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Antipsychotics First Generation Drugs Chlorpromazine Haloperidol Sulpiride Flupentixol Zuclopenthixol Second Generation Drugs Clozapine Olanzipine Quetiapine Risperidone Amisulpride Clinical and Side Effects 1st gen is more associated with EPS. 2nd gen is more associated with metabolic syndrome. Dopamine D2 receptor antagonism: • Mesolimbic: treatment of psychotic symptoms • Mesocortical: worsen negative and cognitive symptoms of schizophrenia • Nigrostriatal pathway: EPS • Parkinsnian symptoms (rigidity, bradykinesia, tremors) • Acute dystonia • Akathisia • Tardive dyskinesia • NMS • Tuberoinfundicular pathway: hyperprolactinaemia — galactorrhea, amenorrhea, sexual dysfunction • Chemoreceptor trigger zone: anti-emetic effect Other side effects: • Anticholinergic (muscarinic): dry mouth, constipation, urinary retention, blurred vision • anti a-adrenergic: postural hypotension • anti histaminergic: sedation, weight gain • Cardiac: prolong QT, arrhythmias, myocarditis, sudden death • Metabolic: increased risk of metabolic syndrome • Dermatological: photosensitivity, skin rashes (especially chlorpromazine with blue-grey discoloration in sun) • Neurological: lowering of seizure threshold • Hepatic: hepatotoxicity, cholestatic jaundice • Hematological: pancytopenia, agranulocytosis *Clozapine is particularly associated with agranulocytosis, myocarditis, and cardiomyopathy. It is reserved for treatment resistant cases Indications • Schizophrenia, schizoaffective disorder, delusional disorder • Depression or mania with psychotic features • Psychotic episodes secondary to medical condition or substance use • Delirium (caution in alcohol withdrawal as it lowers seizure threshold) • Behavioural disturbance in dementia (caution as increased risk of CVA) • Motor tics

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• Nausea and vomiting (prochlorperazine) • Intractable hiccups and pruritis (chlorpromazine, haloperidol) Contraindications/cautions • Severely reduced consciousness level (sedating) • Phaeochromocytoma • Parkinson’s disease • Epilepsy • Cardiac disease (can induce arrhythmias, consider baseline ECG) • Metabolic syndrome • Clozapine should not be re-prescribed to someone with history of agranulocytosis Clozapine Monitoring Clozapine is particularly associated with agranulocytosis, myocarditis, and cardiomyopathy. It is reserved for treatment resistant cases. Blood taking (CBC, LRFT + CaPO4, metabolic — BP, BMI, FPG, lipids) weekly until week 18, then biweekly CBC for one year, and monthly indefinitely.


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Neuroleptic Malignant Syndrome Clinical Features Occurs within 4-11 days of initiation or dose increase of dopamine antagonist (e.g. antipsychotic, metoclopramide). Insidious onset over 1-3 days. Characterised by triad of altered consciousness level, autonomic dysfunction (hyperthermia, sweating, tachycardia, unstable BP), and severe rigidity (dysphagia, dyspnea from pharyngeal and thoracic muscles, bradyreflexia). Complications Rhadomyolysis Acute respiratory failure Acute renal failure (from myoglobinuria) Hyperthermia -> DIC Acquired infections Investigations and Lab Features CBC, PT/PTT -> hyperthermia triggers DIC LFT -> mild enzyme derangement RFT, CaPO4 -> electrolyte disturbances

Urine toxicology -> look for offending drug Urine myoglobin and serum CK -> look for rhadomyolysis Treatment Supportive: Monitor vitals (BP, HR, RR, PaO2) & MSE IV hydration Oxygen Cooling (e.g. cooling blankets, ice packets, ice water enema) Antipyretics Therapeutic: Dopamine agonists: bromocriptine, amantidine Muscle relaxant: dantrolene

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Lithium Indications Acute mania (particularly if optimistic about long term compliance) Prophylaxis of BAD Lithium augmentation in TRD Adjuncts to antipsychotics in psychotic disorders Aggression and impulsivity in personality disorders Contraindications/Caution Pregnancy/breastfeeding Renal impairment Thyroid disease Cardiac disease Neurological disease (e.g. parkinson’s, huntington’s) Therapeutic Range and Toxic Levels Acute range: 0.8-1.2 mmol/L Long term prophylaxis: 0.4-0.8 Toxic above 1.5, dangerously toxic above 2 Side effects Water — thirst, polydipsia, polyuria, impaired renal function, edema, weight gain Fire — fine tremor, concentration/memory issue, Heart blood — T wave flattening or inversion, leucocytosis, hypothyroidism Other — teratogenecity (ebstein’s anomaly in 1st trimester, and other issues) Toxic > 1.5 — n/v, coarse tremors, ataxia, muscle weakness, apathy Toxic > 2.0 — impaired consciousness, nystagmus, dysarthria, hyperreflexia, oliguria, hypotension, coma Lithium withdrawal may precipitate mania Interactions Diuretics (thiazide, lithium clears almost 100% through kidney coupled with sodium, dehydration and hypoNa reduces clearance), NSAID, ACEi increases lithium levels Antipsychotics may increase neurotoxicity Investigations and Monitoring Prior to initiating therapy — FBC, RFT + CaPO4, TFT, pregnancy test, ECG Blood levels monitored every week until therapeutic level stable for 4 weeks. Then levels monitored every 3 months, RFT every 6 months, TFT every 12 months. Treatment of Lithium Toxicity Supportive. Stop the drug. Ensure hydration and electrolytes, anticonvulsants if needed, hemodialysis if renal failure.


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Anticonvulsants Indications Epilepsy Valproate — acute mania, 2nd line prophylactic drug in mania Carbamazapine — 3rd line prophylactic drug in mania Lamotrigene — bipolar depression mood stabiliser, 3rd line prophylactic drug in mania Contraindications Pregnancy/breastfeeding Side effects Valproate: • Sedation and dizziness, N/V • Haematological abnormalities (prolonged bleeding time, thrombocytopenia, leucopenia; serious blood issues rare) • Raised liver enzymes (liver damage rare) • Tremors Carbamazapine • Sedation and dizziness, N/V • Haematological abnormalities (eosinophilia, thrombocytopenia, leucopenia; serious blood issues rare) • Raised liver enzymes (hepatic or cholestatic jaundice rare) • Blurred or double vision • Ataxia • HypoNa and fluid retention Lamotrigene • Sedation and dizziness, N/V • Irritability and aggression • Skin rashes (consider withdrawal) • Headache • Tremors • Steven Johnson Syndrome (0.3%, usually within 2-8 weeks of therapy) • Teratogenicity (cleft palate)

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