Drugs Flashcards
Side effects of clozapine
- Neutropenia/agranulocytosis
- Metabolic syndrome (weight gain, hypercholesterolaemia, diabetes)
- Liver dysfunction
- Postural hypotension
- Tachycardia
- Myocarditis
- Severe constipation which may lead to toxic megacolon
Monitoring for clozapine
- Weekly FBC for first 18 weeks, then monthly
- Monthly weights, fasting glucose and fasting lipids for 3 months, then every 6 months or annually
- Annual LFTs
- Weekly BP/pulse when starting, then based on patient’s status
- Advise patient/caregivers to monitor bowel habits and signs of flu/SOB, heart rate and autonomic instability
When would you use clozapine?
In treatment resistant psychotic disorders
How would you start clozapine?
First day: 12.5mg OD or BD
Second day: 25-50mg OD
Continuation: Increase in increments of 25-50mg daily over 14-21 days
Max: 300mg daily in divided doses
[N.B. can increase further by 50-100mg daily until max of 900mg daily in divided doses if required. However, wean down until the minimum effective dose is reached]
Side effects of antipsychotic medications (e.g. olanzapine, risperidone, quetiapine, aripiprazole, amisulpride, ziprasidone)
- Metabolic syndrome [olanzapine has the greatest risk –> risperidone and quetiapine –> ziprasidone, amisulpride and aripiprazole)
- Parkinson-like ADRs (EPSE) [Risperidone at highest risk, all others have lower risk]
- Akathesia [Olanzapine]
- QTc prolongation
- Raised prolactin [Risperidone & amisulpride]
- Liver dysfunction [all]
Monitoring antipsychotic medication (e.g. olanzapine, risperidone, aripiprazole, amisulpride, ziprasidone)
- Monthly fasting glucose, fasting lipids and weights for 3 months, then 6 months or annually based on risk
- Baseline ECG, repeat if indicated (especially if using other QTc prolongation medications)
- Prolactin levels if symptomatic
- LFTs annually
Side effects of lithium
- Renal impairment
- Thyroid dysfunction (hypo and hyper)
- Lithium toxicity (usually with levels over 1.5mmol/L); includes tremor, ataxia, dysarthria, convulsions, renal impairment and nystagmus
Monitoring of lithium
- eGFR every 6 months
- Urine specific gravity in patients with polyuria
- TSH every 12 months
- Therapeutic levels weekly after initiation or dose changes, then every 3 months or if symptomatic. Note sample must be taken 12 hours after dose (trough)
How do you initiate lithium?
Initially 0.4-1.2g daily as a single dose or in 2 divided doses adjusted according to serum-lithium concentration
Caution in elderly or patients less than 50kg (400mg daily)
How can you treat lithium toxicity?
In mild cases, withdraw the agent and ensure adequate hydration and correction of electrolyte imbalances.
In severe cases, call for help - poisons hotline on NZF!
Side effects of sodium valproate
- Liver dysfunction
- Thrombocytopaenia
- Highly terratogenic - avoid in women of childbearing age or use with effective contraception
Monitoring of sodium valproate
- LFTs, FBC, and serum levels at baseline and then annually
How do you initiate sodium valproate?
Initially 600mg daily in 2-3 divided doses, increased according to response.
Usual maintenance is 1-2g daily (20-30mg/kg daily).
Maximum dose is 2.5g daily
Side effects of SSRIs
- Hyponatremia
- Agitation, tremor, anxiety
- Gastrointestinal symptoms - diarrhoea, constipation, vomiting, nausea, loss of appetite, weight loss
- Dizziness
- Blurred vision
- Dry mouth
- Excessive sweating
- Insomnia or drowsiness
- Decreased libido
- Serotonin Symptom (confusion, agitation, muscle twitching, sweating, shivering,
Monitoring SSRIs
Electrolytes (sodium) at baseline, and then repeat at 2-4 weeks post initiation
