Therapeutic issues with pharmacological management

Question 1

Plasma level monitoring

Answer 1

Reasons for monitoring: establish therapeutic levels, evidence for toxicity, doubt about compliance, in cases where patient unable to report adverse effects (children, severe LD, dementia) and in overdose.
Monitoring for: lithium, carbamazepine, valproate, clozapine

Question 2

Weight gain with psychiatric drugs

Answer 2

Worse with clozapine, chlorpromazine, olanzepine, quetiapine. Lower with risperidone and aripiprazole.
Lithium, mirtazepine, carbamazepine, valproate, gabapentin

Question 3

Diabetes with antipsychotics

Answer 3

Common with SGAs
Need to determine baseline measures of glucose.
Treat with metformin or glucose

Question 4

Hyperprolactinaemia with antipsychotics

Answer 4

Frequent with risperidone and amisulpride. Features include gynaecomastia, galactorrhoea and erectile dysfunction

Question 5

Sexual dysfunction with psychiatric medication

Answer 5

Most likely with these ADs: clomipramine, SSRIs, venlafaxine
Most likely with these: FGAs and risperidone
Mood stabilisers - carbamazepine and phenytoin

Question 6

Priapism

Answer 6

Trazodone is most likely due to alpha blockade

Question 7

Anti-psychotic induced parkison

Answer 7

D2 receptor blockade
Clozapine/quetiapine least likely to effect movement
Use procyclidine anticholinergic

Question 8

Akathisia

Answer 8

More risk in chronic, high dose, IM, rapid increase/sudden withdrawal, organic brain disease
Try chlorpromazine or quetiapine or clozapine
Beta-blockers and low-dose mirtazepine are anti-akathisias

Question 9

Tardive dyskinesia

Answer 9

More common in elderly, organic brain disease

Clozapine best alternative

Question 10

Dystonic reactions

Answer 10

Procyclidine in emergency management, IM and then continue for 5-7 days

Question 11

Neuroleptic malignant syndrome

Answer 11

Rare, idiosyncratic
Fever, muscle rigidity, hyporeflexia, altered mental status, autonomic dysfunction (labile blood pressure, sweating, tachycardia)
Insidious onset over 2 weeks
Antipsychotics, antidepressents, mood stabiliers, antiemetics, methylphenidate
High mortality

Question 12

Serotonin syndrome

Answer 12

A rare, but potentially fatal syndrome
Increase/initiate serotonergic agent
Symptoms: altered mental state, agitation, tremor, shivering, diarrhoea, hyperreflexia, myoclonus, ataxia, and hyperthermia.
Caused by: SSRIs, amfetamines, MAOIs, TCAs, lithium
Low mortality
Reversed with cryptoheptadine

Question 13

Antidepressant discontinuation syndrome

Answer 13

SSRIs - paraesthesia, visual disturbance, shock-like sensation, dizziness, flu-like symptoms, GI symptoms, low mood, irritable, anxious, vivid dreams
Worse with paroxetine - short half-life and venlafaxine
Usually after 1 month treatment and 2-5 days after stopping

Question 14

Hyponatraemia and antidepressants

Answer 14

Probably due to SIADH

Highest risk with citalopram, escitalopram, fluoxetine and sertraline

Question 15

Lithium toxicity

Answer 15

Coarse tremor, vomiting, diarrhoea, slurred speech, ataxia, confusion

Question 16

Drugs after MI/arrhythmias

Answer 16

Antidepressants should be avoided, Sertraline is drug of choice
Olanzepine best, avoid clozapine in first year

Question 17

Drugs in heart failure

Answer 17

Avoid hypotensives (beta-blockers, clozapine, risperidone, TCAs) and fluid retainers (carbamazepine, lithium)

Question 18

Liver disease

Answer 18

Almost all drugs metabolised by liver, apart from lithium and gabapentin
Use lower doses
Avoid anticholinergic drugs (sedating or constipating) as risk hepatic encephalopathy

Question 19

Renal impairment

Answer 19

Low dose as accumulates drugs

Question 20

Epilepsy

Answer 20

AD - use SSRI

Antipsychotics - avoid clozapine and olanzepine

Question 21

Skin rashes

Answer 21

Risk of SJS/TENS with lamotrigine and carbamazepine

Question 22

CYP450 interactions

Answer 22

SSRIs

Carbamazepine

Question 23

Side effects of antipsychotics

Answer 23

Anti-cholinergic - dry mouth, urinary retention, constipation, confusion
Anti-histaminergic - sedation
Anti-adrenergic - postural hypotension (especially chlorpromazine), impotence

Question 24

Side effects of clozapine

Answer 24

Agranulocytosis, seizures, constipation, blood pressure change, weight gain, bedwetting, myocarditis, pulmonary embolism, cardiomyopathy

Question 25

Lithium side effects

Answer 25

Nephrogenic diabetes insipidus, hypothyroidism, metallic taste, fine tremor, hypercalcaemia, renal dysfunction, weight gain, blood dyscrasias, T wave changes, widening of QRS

Question 26

Long QT syndrome

Answer 26

Particularly in chlorpromazine, and antidepressants (especially TCAs)

Question 27

Benzodiazepine withdrawal

Answer 27

Anxiety, insomnia, tremor, agitation, headache, nausea, sweating, depersonalisation, seizures

Question 28

Mood stabilisers measurements pre-therapy

Answer 28

Measure BMI, LFT and FBC

Question 29

Drugs to avoid with lithium

Answer 29

NSAIDs and Thiazide diuretics

Question 30

Investigations with lithium

Answer 30

Lithium levels, BMI, TFTs. U&Es, FBC, ECG

Question 31

Side effects of TCAs

Answer 31

Common: anti-cholinergic cognitive and/or memory impairment Serious: arrhythmias

Question 32

Side effects of NaSSAs

Answer 32

Common: drowsiness, increased appetite and weight gain

Question 33

Side effects from MAOis

Answer 33

Common: dizziness Serious: hypertensive crisis from tyramine reaction (from foods such as mature cheese, salami, pickled herring, Bovril®, Oxo®, Marmite® or any similar meat or yeast extract or fermented soya bean extract, and some beers, lagers or wines) or foods containing dopa (such as broad bean pods) or from sypathomimetics Overdose: mixed serotonin syndrome-hypertensive crisis picture

Question 34

How do you switch from any antidepressant to a MAOi

Answer 34

Two week washout