High risk drugs

Question 1

Phenytoin Toxicity Symptoms

Answer 1

SNAtCHeD
Slurred speech
Nystagmus (uncontrolled repetitive eye movements)
Ataxia
Confusion
Hyperglycemia
Double/blurred vision

Question 2

Phenytoin Range

Answer 2

10-20mg/L, 20-40mmol/L

Question 3

Amiodarone monitoring

Answer 3

Thyroid function, LFTs, K+, chest x ray (fibrosis), ECG (with IV use)

Question 4

Amiodarone warning signs

Answer 4

signs of thyroid dysfunction, liver dysfunction, peripheral neuropathy
corneal deposits - may affect driving at night
progressive SOB
Phototoxic skin reactions/slate grey skin

Question 5

Amiodarone counselling points

Answer 5

Shield skin from direct sunlight until several months post treatment cessation
drivers may be dazzled at night
Drug may have effects for several months post cessation

Question 6

Amiodarone interactions

Answer 6

Increases conc of : coumarins, dabigatran, dig, flecainide, phenindione, phenytoin
Inc risk Vent arrhythmias with: drugs that prolong QT interval.
Inc risk of bradycardia, AV block, myocardial depression with: BB, D&V
myopathy with Simvastatin

Question 7

ACE/ARB monitoring

Answer 7

BP, U&Es

Question 8

ACE/ARB Warning signs

Answer 8

Signs of postural hypotension,
Jaundice/elevated hepatic enzymes
Abnormal renal function (Renal artery stenosis)
Urinary/water retention, confusion, n&v, (signs of AKI)

Question 9

ACE/ARB counselling

Answer 9

immediately report: Dry cough with ACE (1/10 affected)
Need routine U&Es
Need to drink adequate fluid volumes. Stop tking during sick days, when experiencing D&V, fever, sweats and shaking, in order to prevent dehydration and AKI

Question 10

ACE/ARB interactions

Answer 10

Increase Li, K levels

Risk of renal impairment with aliskiren

Question 11

Antipsychotic monitoring

Answer 11

FBC, U&Es, LFT, fasting glucose, blood lipids, BP, weight, ECG.

Question 12

Antipsychotic warning signs

Answer 12

Hyperthermia, muscle rigidity, fluctuating consciousness, tachycardia, labile BP.

Question 13

Antipsychotic actions

Answer 13

ECG to monitor for QT prolongation/other cardiac abnormalities.
Counsel to maintain adequate fluid intake
High risk of relapse w/i first 2 years of stopping, monitor for signs of relapse.
Photosensitivity can occur at higher doses.

Question 14

Antipsychotic dose adjustments/prescribing advice

Answer 14

Elderly, max half starting dose.

Dose increases maximum weekly

Question 15

Antipsychotic interaction

Answer 15

QT prolongation with other QT prolongers such as (es)citalopram.
Inc hypotensive affect of antihypertensives
Increased sedation with antihistamines and anxiolytics
Inc risk of extrapyramidal ADRs with metoclopramide and amantadine

Question 16

Azathioprine monitoring

Answer 16

FBC, renal function, LFTs

Question 17

Azathioprine warning signs

Answer 17

malaise, dizziness, diarrhoea, fever, myalgia, rash (hypersensitivity)
Hypotension, N&V, unexplained bruising/bleeding/infection (bone marrow suppression)

Question 18

Azathioprine action

Answer 18

reduce dose to 1/4 if taking allopurinol
Measure thiopurine methyltransferase (TPMT) before initiation - risk of myelosuppression inc with low TPMT
In RA, withdraw if N&V/diarrhoea occur

Question 19

Azathioprine interactions

Answer 19

Inc risk of anaemia/leucopenia with ACE
Anticoag effect of coumarins reduced
Inc risk of harm toxicity with allopurinol
Inc risk of generalised infections (potentially life threatening with LIVE vaccines)

Question 20

Carbamazepine therapeutic range

Answer 20

4-12mg/L

20-50 micromol/L

Question 21

Carbamazepine monitoring

Answer 21

FBC, renal function, LFTs

Question 22

Carbamazepine Warning signs

Answer 22

Toxicity - incoordination, double/blurred vision, drowsiness, nystagmus, ataxia, arrhythmias, N&V, diarrhoea, hyponatremia
Blood disorders - leucopenia, thrombocytopenia (fever, sore throat, unexplained bruising/bleeding)
Skin disorders - toxic epidermal