Download Monday 23rd December: PSA2

PSA PRACTICE QUESTIONS 2
Calculation
Case presentation
A 24-year-old man requires sutures for extensive lacerations to the face and chest. Lidocaine
hydrochloride 1% with adrenaline (epinephrine) 1:200,000 is used to provide local
anaesthesia before suturing, and a total of 13 mL is injected SC around the wound.
Calculation
How much adrenaline (in micrograms) has been administered?
(Write your answer in the box below)
Answer: 65 micrograms
Answer box
Working
The adrenaline content of the ampoule is 1:200 000.
That means that in every litre (1000 mL, mass 1000 g) the adrenaline content is 1000/200 000
= 0.005 g = 5 mg = 5000 micrograms.
Therefore, 13 mL contains 5000 x 13/1000 micrograms = 65 micrograms.
(Note: 1. You will have a calculator provided for the exam 2. This dilution of adrenaline is used only
in combined formulations, on its own it is 1:1000 or 1:10000 almost always and 1:1000 = 1mg/ml 3.
Their calculations are much simpler than the ones we used to have in our own exam!)
Calculation
Case presentation
A 60-year-old woman with chronic renal impairment is to be given alfacalcidol 1 microgram
orally daily. Alfacalcidol is available as capsules each containing 250 nanograms.
Calculation
How many capsules of alfacalcidol should she be given daily?
(Write your answer in the box below)
Answer: 4 capsules
Answer box
Working
Dose required = 1 microgram = 1000 nanograms.
Each capsule contains 250 nanograms.
Number of capsules to be given = 1000/250 = 4.
Adverse drug reactions-management
Case presentation
A 25-year-old man presents to the emergency department after the sudden onset of painful
spasm in his neck. PMH. Psychotic episodes of recent onset. DH. The previous day he was
given oral haloperidol and lorazepam according to a rapid tranquillization protocol to treat his
agitation. He is now taking haloperidol 5 mg orally 12-hrly and lorazepam 2 mg orally 12hrly.
Question
Select the most appropriate option for the immediate management of this adverse drug
reaction.
(mark it with a tick)
A
MANAGEMENT OPTIONS
additional dose of haloperidol 5 mg orally
B
additional dose of lorazepam 2 mg orally
C
reduce dosage of haloperidol to 3 mg orally 12-hrly
D
reduce dosage of lorazepam to 1 mg orally 12-hrly
E
single dose of procyclidine 5 mg IM
Answer box
Option A Justification
This will worsen the extrapyramidal effect caused by haloperidol.
Option B Justification
This will not have any effect on the acute dystonia.
Option C Justification
This will not have an immediate effect. It would be preferable to substitute an antipsychotic
that has less tendency than haloperidol to cause extrapyramidal effects, thereby lessening the
likelihood of recurrent dystonia.
Option D Justification
The adverse drug reaction is not related to benzodiazepine use.
Option E Justification
This antimuscarinic drug will act against the antidopaminergic effects of haloperidol in the
basal ganglia and relieve the spasm. BNF recommends IM or IV administration for acute
dystonia.
Data
Case presentation
A 67-year-old man with carcinoma of the colon has been admitted with increasing abdominal
pain. His pain was controlled for several weeks by morphine sulphate m/r (MST Continus®)
60 mg orally 12-hrly. Over the last few days he has required three additional doses each day
of morphine sulphate immediate release (Sevredol®) 20 mg orally. This has controlled his
pain well and he has noticed no adverse effects.
Question
Select the most appropriate decision option with regard to the MST Continus® prescription.
(mark it with a tick)
A
DECISION OPTIONS
120 mg orally 12-hrly
B
200 mg orally 12-hrly
C
60 mg orally 12-hrly
D
60 mg orally 8-hrly
E
90 mg orally 12-hrly
Answer box
Option A Justification
This dose exceeds the 200 mg/24 hours daily morphine dose required for good analgesia and
significantly increases the risk of adverse effects.
Option B Justification
This dose exceeds the 200 mg/24 hours daily morphine dose required for good analgesia and
significantly increases the risk of adverse effects.
Option C Justification
His pain is well controlled with no adverse effects by a total daily dose of 180 mg/24 hours.
The background analgesic dose should be adjusted to take this into consideration. Continuing
with MST Continus® 60 mg means the patient will experience unnecessary pain episodes.
Option D Justification
MST Continus® is a modified-release preparation of morphine that has been designed to be
administered on a 12-hourly basis.
Option E Justification
His pain is well controlled with no adverse effects by a total daily dose of 180 mg/24 hours.
The background analgesic dose should be adjusted to take this into consideration.
Therapeutic monitoring
Case presentation
A 45-year-old man is found by his GP to have persistently raised blood pressure over the
previous month. His baseline biochemical profile is normal.
The GP prescribes candesartan cilexetil 8 mg orally daily.
Question
Select the most appropriate monitoring option to assess the adverse effects of this treatment
after 2 weeks.
(mark it with a tick)
A
MONITORING OPTIONS
fasting blood glucose
B
liver function tests
C
renal function
D
serum cholesterol
E
serum sodium
Answer box
Option A Justification
Angiotensin II receptor antagonists do not induce hyperglycaemia.
Option B Justification
This monitoring is appropriate for statins and some ACE inhibitors but candesartan does not
usually affect liver function tests.
Option C Justification
Renal function should be measured 1–2 weeks after starting an angiotensin II receptor
blocker.
Option D Justification
Whilst cholesterol measurement will be necessary to outline CVD risk, monthly monitoring
for 6 months Is excessive and unhelpful and unrelated to ADR of candesartan.
Option E Justification
Serum potassium may be increased by candesartan and should be monitored. Hyponatraemia
has been reported with candesartan, but very rarely.
Management
Case presentation
A 72-year-old man is found to have poor urine output 10 days after undergoing an anterior
resection for colorectal carcinoma. PMH. Hypertension. DH. Bendroflumethiazide 2.5 mg
orally daily, cyclizine 50 mg orally 8-hrly, and oxycodone m/r 10 mg orally 12-hrly.
On examination
Temperature 38.3°C, HR 120/min and rhythm regular, BP 78/46 mmHg, JVP not visible, RR
22/min, O2 sat 93% (94–98) breathing air. 85 mL of urine has been passed over the last 6
hours.
Question
Select the most appropriate immediate management option.
(mark it with a tick)
A
MANAGEMENT OPTIONS
furosemide 40 mg by slow IV injection
B
Gelofusine® 4% 500 mL IV over 15 minutes
C
glucose 5% 1 L IV over 30 minutes
D
packed red blood cells 1 unit over 2 hours
E
sodium chloride 0.9% 250 mL IV over 10 minutes
Answer box
Option A Justification
Furosemide does not improve outcomes in acute kidney injury (AKI). It may be indicated
where AKI is complicated by pulmonary oedema, but this is probably not the case here
(patient not complaining of dyspnoea; low JVP).
Option B Justification
A crystalloid solution is preferred in the first instance, and if plasma expansion is required
subsequently, albumin should be preferred to plasma substitutes where peritonitis is
suspected.
Option C Justification
Glucose 5% is not a suitable preparation for plasma volume expansion as it distributes
throughout total body water.
Option D Justification
In the absence of bleeding or evidence of significant blood loss, transfusion is unnecessary
and much more dangerous than infusion of crystalloid solution.
Option E Justification
He has signs of intravascular volume depletion. Plasma volume expansion is required. An
initial fluid challenge with sodium chloride 0.9% is reasonable.
Prescribing
Case presentation
A 53-year-old Afro-Caribbean woman is reviewed by her GP following ambulatory blood
pressure (BP) monitoring, which indicated an average BP of 160/96 mmHg. PMH.
Dyspepsia. DH. Lansoprazole 15 mg orally daily. SH. She eats a sensible diet, smokes 10
cigarettes per day and rarely drinks alcohol.
On examination
HR 62/min and rhythm regular. Fundoscopy normal. Urinalysis normal.
Investigations
FBC, renal, liver and thyroid function tests, fasting plasma glucose and HbA1c normal.
Serum cholesterol 4.9 mmol/L (<5.2), HDL cholesterol 1.60 mmol/L (>1.55).
ECG normal.
Her 10-year cardiovascular risk is estimated to be 12.8%.
The GP diagnoses Stage 2 hypertension and recommends antihypertensive drug treatment.
Prescribing request
Write a prescription for ONE drug that is most appropriate to manage her blood pressure
initially.
Calcium channel blockers
4
Thiazides and similar diuretics, ACE inhibitors, ARBs
3
Beta-blockers
2
Hydralazine, clonidine, spironolactone, aliskiren
1
(Again, dose must be correct to get full marks)
Prescription review
Case presentation
A 78-year-old woman visits her GP for a medication review. She is asymptomatic. PMH.
Alzheimer's disease. She had a minor stroke last year and also has a history of osteoporosis
and a hiatus hernia. DH. Her current regular medicines are listed (right). SH. She lives in a
care home and the nurses report no behavioural problems.
Question A
Select the ONE prescription which should be discontinued in light of her recent stroke.
(mark it with a tick in column A)
Question B
Select the ONE prescription that contains a dosing error.
(mark it with a tick in column B)
Resource associated with this item:
No resource has been associated with this item.
CURRENT PRESCRIPTIONS
Drug
Dose Route Freq.
aspirin
75 mg ORAL daily
A B
calcium and ergocalciferol 1 tablet ORAL daily
donepezil hydrochloride
5 mg
ORAL nightly
ranitidine
300 mg ORAL nightly
risedronate sodium
35 mg ORAL daily
risperidone
1 mg
senna
15 mg ORAL nightly
ORAL nightly
Answer box
Question A
All antipsychotics should be used with caution in the
elderly due to the increased risk of cerebrovascular disease
and increased mortality.
Question B
35 mg is the weekly dose of
risedronate – 5 mg is used for
daily dosing .