PHARMACOLOGY
Questions&Answers
Q-1
A 68 year old male patient is on Ramipril 10 mg daily and Bendroflumethiazide 2.5
mg daily for hypertension. He has come for his routine checkup with a blood
pressure of 135/85 mmHg. His blood tests show:
Serum potassium level 5.9 mmol/L
Serum sodium 126 mmol/L
Serum creatinine 79 micromol/L
What is the SINGLE most likely side effect of thiazide diuretics which contributed
to his blood results?
A. Hypocalcemia
B. Hyponatraemia
C. Hypouricaemia
D. Hyperkaleimia
E. Hypernatraemia
ANSWER:
Hyponatraemia
EXPLANATION:
One of the many known adverse effects of thiazides is postural hypotension.
Common adverse effects of thiazides worth remembering include:
• Postural hypotension
• Hyponatraemia, hypokalaemia
• gout
THIAZIDE DIURETICS, LOOP DIURETICS, POTASSIUM-SPARING DIURETICS
COMPARISON
Important key points:
• Thiazide and Loop diuretics – Hyponatraemia, hypokalaemia and also gout
• Thiazide diuretics – Postural hypotension
• Spironolactone – Hyponatraemia, hyperkalaemia
Thiazide diuretics
The main use of bendroflumethiazide was in the management of hypertension but
recent NICE guidelines now recommend other thiazide-like diuretics
,Commonly asked side effects include
• Postural hypotension
• Hyponatraemia
• Hypokalaemia
• Gout
• Impaired glucose tolerance
Loop diuretics
Example: Furosemide – Used especially in heart failure
Commonly asked side effects include
• Hypnatraemia
• Hypokalaemia
• Gout
Potassium-sparing diuretics
Example: Spironolactone
Commonly asked side effects include
• Hyperkalaemia
• Hyponatraemia
• Gynaecomastia
Q-2
A 55 year old man on anti-hypertensives develops hyperkalaemia. What is the
SINGLE most likely anti-hypertensive drug to cause it?
A. Nifedipine
B. Indapamide
C. Bendroflumethiazide
D. Enalapril
E. Amlodipine
ANSWER:
Enalapril
EXPLANATION:
ACE-inhibitors can cause hyperkalaemia. Concomitant treatment with NSAIDs
increases the risk of renal damage, and potassium-sparing diuretics increase the risk of
hyperkalaemia. It would be a good idea to recognise common ACE inhibitors –
Ramipril, Enalapril, Captopril, Perindopril and Lisinopril.
If there is no option for ACE inhibitors, then Angiotensin-II receptor blockers (ARBs)
would be the next best option as these can too cause hyperkalaemia. Common ARBs
to know are Losartan, Candesartan and Valsartan.
Q-3
A 10 month old child who weighs 10 kilograms has been diagnosed with a urinary
tract infection. He has been prescribed trimethoprim at a dose of 4 mg/kg to be
given twice daily. The preparation of trimethoprim is 50 mg/5 ml. What dose will
you advise the parents to give to the child?
,A. 10 ml BD
B. 4 ml BD
C. 5 ml BD
D. 4 ml OD
E. 5 ml OD
ANSWER:
4 ml BD
EXPLANATION:
This question requires a sound understanding of mathematics and not medicine. The
prescribed dose is 4 mg/kg body weight. The child weighs 10 kilograms, therefore the
dose needed will be 40 mg.
A preparation of 50 mg/5 ml is equivalent to 10 mg per mL. Therefore, 40 mg is
equivalent to 4 ml. It has to be given twice daily so 4 ml BD is the correct answer.
Q-4
Which of the following drugs can cause bronchoconstriction?
A. Atenolol
B. Salbutamol
C. Salmeterol
D. Ipratropium bromide
E. Theophylline
ANSWER:
Atenolol
EXPLANATION:
Atenolol is a beta blocker. Beta blockers are known to cause bronchoconstriction.
Salbutamol and salmeterol are beta agonists. They are used to treat bronchospasm
thus they have bronchodilating effects.
Ipratropium bromide inhibits bronchoconstriction
Theophylline also relaxes the bronchial smooth muscle causing bronchodilation.
Q-5
A 56 year old man whose pain was relieved by oral Morphine, now presents with
progressively worsening pain. Increasing the dose of oral morphine helps to
relieve his pain. However, he now complains that the increased morphine makes
him drowsy and he is unable to carry out his daily activities. What is the SINGLE
most appropriate next step?
A. Replace oral morphine with oral oxycodone
B. Replace oral morphine with oral tramadol
C. Patient-controlled analgesia (PCA)
D. Intravenous fentanyl
E. Intravenous diamorphine
, ANSWER:
Replace oral morphine with oral oxycodone
EXPLANATION:
In general, oxycodone should be used when patients are still in pain but have side
effects of opioids. This is because oxycodone has twice the potency of morphine to
manage pain but with lesser side effects compared to morphine.
The pain ladder consist of 3 steps:
1: Simple analgesia like paracetamol. Aspirin, NSAIDs +/- adjuvant therapy
2: Weak opiates: e.g codeine, tramadol, dihydrocodeine +/- adjuvant therapy
3. Strong opiates: morphine, fentanyl patches, diamorphine, oxycodone +/- adjuvant
therapy.
If patient is still in pain, you should never go back a step on the pain ladder, only go
forward.
Q-6
A 74 year old woman with breast cancer and bone metastasis has her pain
relieved with oral morphine 60 mg twice a day. For the past 2 weeks she has
needed to use an additional 20 mg of oral morphine every 4 hours. What is the
SINGLE most appropriate regimen of analgesia to prescribe?
A. Tramadol 100 mg every 4 hours
B. Oral morphine 120 mg twice a day and 5 mg oral morphine as required
C. Oral morphine 120 mg twice a day and 10 mg oral morphine as required
D. Oral morphine 240 mg twice a day and 10 mg oral morphine as required
E. Oral morphine 120 mg twice a day and 40 mg oral morphine as required
ANSWER:
Oral morphine 120 mg twice a day and 40 mg oral morphine as required
EXPLANATION:
It is particularly important to remember how to calculate breakthrough doses in palliative
care for pain relief.
If someone is taking PRN morphine regularly for a while, they should have their pain
relief reassessed and increased. In this stem, we all can agree that the regular oral
morphine dose needs to be increased.
Calculation of the dose to give for breakthrough pain is easy once you understand it.
The dose of normal release morphine for breakthrough pain should be 1/6 of the total
24 hour morphine dose.
In this stem, increasing the oral morphine to 120 mg BD means that the total amount of
morphine in 24 hours is 240 mg. Breakthrough pain dose should be 240 mg/6 which is
40 mg. Hence, 40 mg of oral morphine should be prescribed as 4 hourly PRN in
addition to the BD dose of morphine.
INTERESTING FACT:
This method of using one sixth of the total 24 hour dose as a breakthrough dose is a
traditional method. Now, with the newer modified-release analgesia, some physicians
Questions&Answers
Q-1
A 68 year old male patient is on Ramipril 10 mg daily and Bendroflumethiazide 2.5
mg daily for hypertension. He has come for his routine checkup with a blood
pressure of 135/85 mmHg. His blood tests show:
Serum potassium level 5.9 mmol/L
Serum sodium 126 mmol/L
Serum creatinine 79 micromol/L
What is the SINGLE most likely side effect of thiazide diuretics which contributed
to his blood results?
A. Hypocalcemia
B. Hyponatraemia
C. Hypouricaemia
D. Hyperkaleimia
E. Hypernatraemia
ANSWER:
Hyponatraemia
EXPLANATION:
One of the many known adverse effects of thiazides is postural hypotension.
Common adverse effects of thiazides worth remembering include:
• Postural hypotension
• Hyponatraemia, hypokalaemia
• gout
THIAZIDE DIURETICS, LOOP DIURETICS, POTASSIUM-SPARING DIURETICS
COMPARISON
Important key points:
• Thiazide and Loop diuretics – Hyponatraemia, hypokalaemia and also gout
• Thiazide diuretics – Postural hypotension
• Spironolactone – Hyponatraemia, hyperkalaemia
Thiazide diuretics
The main use of bendroflumethiazide was in the management of hypertension but
recent NICE guidelines now recommend other thiazide-like diuretics
,Commonly asked side effects include
• Postural hypotension
• Hyponatraemia
• Hypokalaemia
• Gout
• Impaired glucose tolerance
Loop diuretics
Example: Furosemide – Used especially in heart failure
Commonly asked side effects include
• Hypnatraemia
• Hypokalaemia
• Gout
Potassium-sparing diuretics
Example: Spironolactone
Commonly asked side effects include
• Hyperkalaemia
• Hyponatraemia
• Gynaecomastia
Q-2
A 55 year old man on anti-hypertensives develops hyperkalaemia. What is the
SINGLE most likely anti-hypertensive drug to cause it?
A. Nifedipine
B. Indapamide
C. Bendroflumethiazide
D. Enalapril
E. Amlodipine
ANSWER:
Enalapril
EXPLANATION:
ACE-inhibitors can cause hyperkalaemia. Concomitant treatment with NSAIDs
increases the risk of renal damage, and potassium-sparing diuretics increase the risk of
hyperkalaemia. It would be a good idea to recognise common ACE inhibitors –
Ramipril, Enalapril, Captopril, Perindopril and Lisinopril.
If there is no option for ACE inhibitors, then Angiotensin-II receptor blockers (ARBs)
would be the next best option as these can too cause hyperkalaemia. Common ARBs
to know are Losartan, Candesartan and Valsartan.
Q-3
A 10 month old child who weighs 10 kilograms has been diagnosed with a urinary
tract infection. He has been prescribed trimethoprim at a dose of 4 mg/kg to be
given twice daily. The preparation of trimethoprim is 50 mg/5 ml. What dose will
you advise the parents to give to the child?
,A. 10 ml BD
B. 4 ml BD
C. 5 ml BD
D. 4 ml OD
E. 5 ml OD
ANSWER:
4 ml BD
EXPLANATION:
This question requires a sound understanding of mathematics and not medicine. The
prescribed dose is 4 mg/kg body weight. The child weighs 10 kilograms, therefore the
dose needed will be 40 mg.
A preparation of 50 mg/5 ml is equivalent to 10 mg per mL. Therefore, 40 mg is
equivalent to 4 ml. It has to be given twice daily so 4 ml BD is the correct answer.
Q-4
Which of the following drugs can cause bronchoconstriction?
A. Atenolol
B. Salbutamol
C. Salmeterol
D. Ipratropium bromide
E. Theophylline
ANSWER:
Atenolol
EXPLANATION:
Atenolol is a beta blocker. Beta blockers are known to cause bronchoconstriction.
Salbutamol and salmeterol are beta agonists. They are used to treat bronchospasm
thus they have bronchodilating effects.
Ipratropium bromide inhibits bronchoconstriction
Theophylline also relaxes the bronchial smooth muscle causing bronchodilation.
Q-5
A 56 year old man whose pain was relieved by oral Morphine, now presents with
progressively worsening pain. Increasing the dose of oral morphine helps to
relieve his pain. However, he now complains that the increased morphine makes
him drowsy and he is unable to carry out his daily activities. What is the SINGLE
most appropriate next step?
A. Replace oral morphine with oral oxycodone
B. Replace oral morphine with oral tramadol
C. Patient-controlled analgesia (PCA)
D. Intravenous fentanyl
E. Intravenous diamorphine
, ANSWER:
Replace oral morphine with oral oxycodone
EXPLANATION:
In general, oxycodone should be used when patients are still in pain but have side
effects of opioids. This is because oxycodone has twice the potency of morphine to
manage pain but with lesser side effects compared to morphine.
The pain ladder consist of 3 steps:
1: Simple analgesia like paracetamol. Aspirin, NSAIDs +/- adjuvant therapy
2: Weak opiates: e.g codeine, tramadol, dihydrocodeine +/- adjuvant therapy
3. Strong opiates: morphine, fentanyl patches, diamorphine, oxycodone +/- adjuvant
therapy.
If patient is still in pain, you should never go back a step on the pain ladder, only go
forward.
Q-6
A 74 year old woman with breast cancer and bone metastasis has her pain
relieved with oral morphine 60 mg twice a day. For the past 2 weeks she has
needed to use an additional 20 mg of oral morphine every 4 hours. What is the
SINGLE most appropriate regimen of analgesia to prescribe?
A. Tramadol 100 mg every 4 hours
B. Oral morphine 120 mg twice a day and 5 mg oral morphine as required
C. Oral morphine 120 mg twice a day and 10 mg oral morphine as required
D. Oral morphine 240 mg twice a day and 10 mg oral morphine as required
E. Oral morphine 120 mg twice a day and 40 mg oral morphine as required
ANSWER:
Oral morphine 120 mg twice a day and 40 mg oral morphine as required
EXPLANATION:
It is particularly important to remember how to calculate breakthrough doses in palliative
care for pain relief.
If someone is taking PRN morphine regularly for a while, they should have their pain
relief reassessed and increased. In this stem, we all can agree that the regular oral
morphine dose needs to be increased.
Calculation of the dose to give for breakthrough pain is easy once you understand it.
The dose of normal release morphine for breakthrough pain should be 1/6 of the total
24 hour morphine dose.
In this stem, increasing the oral morphine to 120 mg BD means that the total amount of
morphine in 24 hours is 240 mg. Breakthrough pain dose should be 240 mg/6 which is
40 mg. Hence, 40 mg of oral morphine should be prescribed as 4 hourly PRN in
addition to the BD dose of morphine.
INTERESTING FACT:
This method of using one sixth of the total 24 hour dose as a breakthrough dose is a
traditional method. Now, with the newer modified-release analgesia, some physicians
