Psychiatric drugs Flashcards
What is the cause of neuroleptic malignant syndrome?
Initiation or increase in dose of antipsychotics (D2 antagonist)
What are the signs of neuroleptic malignant syndrome?
Fever + triad of NM abnormalities (rigidity + hyporeflexia), ANS dysfunction (tachycardia, HT, labile BP, urinary incontinence), fluctuating LOC
How to investigate neuroleptic malignant syndrome?
High CPK
High WCC
LRFT: metabolic acidosis, high ALT
How to manage neuroleptic malignant syndrome?
Pharm: dantrolene + lorazepam
Supportive: hydration, O2, lower temperature (cooling blanket, antipyretic)
What is the cause of serotonin syndrome?
High serotonin e.g. SSRI overdose, DDI between MAOI & SSRI
What are the signs of serotonin syndrome?
Fever + triad of NM abnormalities (myoclonus, tremor, hyperreflexia), altered LOC, ANS dysfunction
How to investigate serotonin syndrome?
High CPK
High WCC
LRFT: high ALT, metabolic acidosis
How to manage serotonin syndrome?
Cyproheptadine (serotonin antagonist)
What are the features of EPSE?
Acute dystonia: oculagyral crisis, torticollis, tongue protrusion, grimacing, ophisthotonus
Akathisia: restlessness, agitation, suicidal ideation
Parkinsonism: tremor, rigidity, akinesia, stooped posture
Tardive dyskinesia: chewing/sucking movement, grimacing, akathisia, choreoathetoid movement
How to manage EPSE?
Acute dystonia: parenteral anticholinergic (benzatropin)
Akathisia: reduce dose, propanolol, short term BZD
Parkinsonism: oral anticholinergic (benzatropin)
Tardive dyskinesia: stop drug, give vitamin E / BZD / tetrabenazine, switch to clozapine
What are the SE of typical antipsychotics?
EPSE, hyperprolactinemia, neuroleptic malignant syndrome, anti-HAM effects
What are the SE of atypical antipsychotics?
Metabolic syndrome
Elevated liver enzyme
Prolonged QT
Anti-HAM, HSR1
What are the indications of lithium?
Mania (acute, maintenance) Depressive episode (BAD, resistant depression)
What are the contraindications of lithium?
Pregnancy & breastfeeding
Impaired RFT
What are the SE of lithium?
CV: T wave inversion, Ebstein’s anomaly, mild leucocytosis
GI upset
Hypothyroidism
Renal: NDI, edema
CNS: fine tremor, weakness, impaired conc & memory, sedative
Factors that increase lithium levels
NSAID, aspirin
Thiazide diuretics
Dehydration (e.g. V/D, pyrexia), hyponatremia
Impaired RFT
What are the signs of lithium toxicity?
1.5-2mmol/L: N/V/D, coarse tremor, apathy, ataxia, muscle weakness
>2mmol/L: nystagmus, dysarthria, hyperreflexia, oliguria, hypotension, impaired LOC, convulsion, coma
How to manage lithium toxicity?
Supportive: hydration, RFT, electrolyte, ECG
Stop lithium
+/- anticonvulsants, renal dialysis (for RF)
What are the teratogenic effects of lithium?
Ebstein’s anomaly: 20X
Neonatal goitre, arrhythmia, hypotonia
How to advice female patient of reproductive age who is on lithium?
Advice contraception
Delay pregnancy until taper off
If already pregnant: valproate + folic acid
What are the indications of valproate?
Acute mania
Bipolar maintenance
Epilepsy
What are the contraindications of valproate?
Pregnancy (neural tube defect)
Weak liver function (monitor LFT & hematological function)
What are the SE of valproate?
Common: sedative, dizzy, tremor, N/V
Less common: HBP (hepatotoxicity, pancreatitis), hemat (thrombocytopenia, leukopenia), constitutional (weight gain, hair loss)
What are the indications of carbamazepine?
Mania
Epilepsy
Trigeminal neuralgia
What are the contraindications of carbamazepine?
Weak liver function (monitor LFT & hematological function)
CV: conduction defect, HF
On MAOI & lithium (neurotoxicity)
HLA-B1502 gene
What are the SE of carbamazepine?
Common: ataxia, diplopia, dizzy/drowsy, nausea Agranulocytosis, aplastic anemia Water retention Teratogenic (neural tube defect) Liver failure, hepatitis SJS, TEN
Can valproate and carbamazepine be used in pregnancy?
Risk of neural tube defect -> avoid if possible
Valproate higher risk than carbamazepine
If necessary: low dose monotherapy + folic acid (5mg daily) for 1m before conception
Carbamazepine in 3rd trimester: vitamin K for mother & baby
What are the indications of lamotrigine?
Bipolar depression
What are the contraindications of lamotrigine?
HLA-B1502 gene
Depression
Suicidal
What are the SE of lamotrigine?
Neuro: ataxia, dizzy/drowsy, diplopia, headache, sedation
SJS
Teratogenic (cleft palate)
Examples of typical antipsychotics
Chlorpromazine, phenothiazine
Loxapine
Haloperidol
Examples of atypical antipsychotics
Olanzapine
Risperidone
Quetiapine
Clozapine