ToThe Controller of ExaminationsUniversity of Health SciencesLahore

Subject: Model OSPE (Objectively Structured Performance Evaluation) Questions of Pharmacology for 2 nd Professional MBBS Examination

With reference to your letter No. UHS/CE-08/801, dated 17-06-2008, the detailed list of laboratory activities in the department of Pharmacology & Therapeutics that the students perform at Lahore Medical & Dental College during the course of study, is attached along with 32 OSPE questions.

Yours Sincerely,

Head of Department of Pharmacology & TherapeuticsLahore Medical & Dental CollegeLahore

List of Experiments Performed by Students at LMDC

The following experimental pharmacology practicals are performed by students of 3rd Year MBBS during the course of study:

1. To demonstrate the effects of drugs on Rabbit’s eyes (Parasympathomimetics, Anti-cholinergics, sympathomimetics and local anesthetics)

2. To Identify the group of the unknown drug by demonstrating its effects on Rabbit’s eyes3. To Draw a simple dose response curve of Acetylcholine’s effects on rabbit’s ileum4. To demonstrate competitive antagonism between Acetylcholine and Atropine by observing

their actions on rabbit’s ileum5. To demonstrate the effects of different drugs (Propranolol, Adrenaline, Acetylcholine and

Atropine) on frog’s heart6. To determine effect on the reflex time of frog after application/administration of various

drugs (Caffeine, diazepam and Lignocaine)7. To determine the effects of various drugs (Phenylephrine/Xylometazoline, Prazosin,

Adrenaline, Acetylcholine) on blood vessels of frog8. To record and calculate biostatistical data including Mean, variance, Standard deviation,

Standard error of the Mean, t value and P values from T tables and its significance, by taking readings of BP/Pulse from 6 subjects.

Model OSPE Questions with Key

OSPE Questions for Observed Stations

Q1. Determine the faults in the following experimental set-up

Requirements for Organizer/StudentFaulty experimental set-up of organ bath

Key for ExaminerStudents shall be assessed whether they have checked the following on a faulty experimental set-up

S. No Assess Marks1 Proper Oxygenation 12 Proper temperature of Organ Bath 13 Balanced lever with Plastocine etc 14 Proper placing of clamps 15 Tyroid’s Solution and writing pen (Present) 16 Proper Placement of Tissue 1

Q 2. Identify the group of the unknown drug by observing its effects on Rabbit’s eyes

Requirements for Organizer/StudentUnknown DrugRabbit (Unknown drug has already been instilled into one eye)TorchCotton WoolScale

Key for ExaminerStudents shall be assessed for performing the following:

S. No Assess/Perform Marks1 Measure the size of the pupil of rabbit’s eyes (initial

size before drug was added will be told)1

2 Perform light reflex on rabbit’s eyes 13 Perform corneal reflex on rabbit’s eyes 14 Note the colour of conjunctiva of rabbit’s eyes 15 Identify possible group of the unknown drug 16 Give specific examples of unknown drug 1

Q 3 Prepare Acetylcholine solutions of different strength and Prepare 1 Liter of Tyroid’s Solution and 1 Liter of Ringer’s Solution

Requirements for Organizer/StudentAcetylcholine Solution of strength 10-3, 10-4, 10-5 and 10-6 solutionsDifferent reagents for preparation of Tyroid’s solution and Ringer’s solutionApparatus (Flasks, beakers, test tubes etc)

Key for Examiner

S. No Assess/Perform Marks1 Prepare 10-4 strength solution from 10-3

Acetylcholine1

2 Take 1 μg of ACH from 10-5 and/or 10-6 solutions 13 Choose the correct chemicals for preparation of

Tyroid’s Solution1

4 Prepare 1 Liter of Tyroid’s solution using correct measurements of chemicals

1

5 Choose the correct chemicals for preparation of Ringer’s solution

1

6 Prepare 1 Liter of Ringer’s solution using correct measurements of chemicals

1

Q. 4 Record Contractions and Obtain Simple Dose Response Curve of Acetylcholine on Rabbit’s Ileum

Requirements for Organizer/StudentExperimental setup of Organ Bath with Rabbit’s Ileum as tissue

Key for Examiners

S. No Assess/Perform Marks1 Take Baseline Reading 12 Add next dose of Acetylcholine 13 Take reading after specific time 14 Wash the preparations after specific times 15 Know how to draw a dose response curve from a set

of readings 1

6 Give Significance of Log-dose response curve 1

Q. 5 Demonstrate the effects of the Given Drugs on Frog’s Heart

Requirements for Organizer/StudentExperimental setup of Frog’s Heart with KymographDrugs to be administered (Adrenaline, Propranolol, Acetylcholine and Atropine)

Key for Examiners

S. No Assess/Perform Marks1 Take a baseline reading 12 Add a dose of Given agonist drug 13 Record contractions 14 Wash, take baseline and add antagonist and record

contractions1

5 Record contractions of antagonist followed by agonist

1

6 Give explanation for above reading 1

Q. 6 Take Data of BP/Pulse of simulated subjects and Calculate Biostatistical Values

Requirements for Organizer/StudentBP apparatusSimulated subjectst table charts

Key for Examiners

S. No Assess/Perform Marks1 Take the BP/Pulse of 6 subjects before and after

exercise1

2 Calculate the means of observations 13 Calculate the standard deviations 14 Calculate the Standard error of the means 15 Calculate the t value 16 Find out the P Value from Given t table charts and

Give significance of its value1

Q. 7 Determine reflex times of frog after application of various drugs

Requirements for Organizer/StudentExperimental setup for practical of Reflex time of frogInjections Caffeine, Diazepam and Lignocaine Key for Examiners

S. No Assess/Perform Marks1 Take normal reflex time 12 Apply Lignocaine and note reflex time 13 Inject caffeine and note reflex time 14 Inject diazepam and note reflex time 15 Inference of above readings 16 Explain above inference 1

Q. 8 Demonstrate competitive antagonism between Acetylcholine and Atropine

Requirements for Organizer/StudentExperimental Setup of dose response curve of acetylcholineAcetylcholine solutions of different strengthsAtropine solutions of different strengths

Key for examinersA simple dose response curve has been obtained of Acetylcholine on isolated rabbit’s ileum. Students will be asked to proceed to demonstrate competitive antagonism

S. No Assess/Perform Marks1 Take submaximal dose or next dose of

Acetylcholine and a dose of atropine1

2 Record contractions 13 Continue by increasing dose of Acetylcholine while

keeping dose of atropine constant1

4 Students should know when to stop 15 Draw dose response curve of agonist in presence of

antagonist 1

6 Show effect of shift of curve (Right parallel shift) 1

OSPE Questions for Unobserved Stations (UOS)

UOS No. 1 Pharmacy Related Calculations

1. Give calculations for preparing and dispensing 120 ml of 10% Dextrose in Normal Saline

Keya) Calculate the amount of NaCl required

For 100ml of distilled water NaCl required = 0.9 gm or 900mg

For 1ml of distilled water NaCl required = 900/100 mg

For 120 ml of distilled water, NaCl required = 900/100 X 120= 1080mg

Thus 1080 mg of NaCl is required

b) Calculate the amount of dextrose required

For 100ml of distilled water dextrose required = 10gm

For 1ml of distilled water dextrose required = 10/100 gm

For 120 ml of distilled water dextrose required = 10/100 X 120 = 12 gm

Thus 12gm of Dextrose is required

2. Give calculations for preparing and dispensing 5 powders each containing 30mg of Phenobarbitone

Key

We calculate for 6 powders, one for wastagea) To calculate the amount of Phenobarbitone

For one powder, Phenobarbitone required = 30mgFor six powders, Phenobarbitone required = 30 x 6 = 180 mg

b) To calculate the amount of diluent (lactose)The minimum weight of any powder should be 120 mgTo make 120 mg we add a diluent i.e. lactose So minimum weight of one powder =120 mgMinimum weight of six powders = 120 X 6

= 720mgAmount of lactose required = Net weight of 6 powders Total weight of Phenobarbitone

= 720 180 = 540mg

UOS No. 2 Pharmacokinetic Related Calculations

3. First & Zero Order Kinetics

Drug A (Half-life 4 Hours) is undergoing first order kineticsDrug B is undergoing zero order kineticsGive presumptive calculations of their plasma concentrations after different times (initial plasma concentration is 100mg/dl for both

Key

Time Drug A (mg/dl) Drug B (mg/dl)0 Hours 100 1004 Hours 50 808 Hours 25 6012 Hours 12.5 4016 Hours 6.25 20

4. Calculate the dose of a drug for a) A child aged 2 years (Adult dose = 100 mg/day)b) A child weighing 20 kg (Adult dose = 50mg/day)c) A person with body surface area (BSA) of 2.1 m2 (Adult dose = 25mg/day)

Key

a) Young’s formula Dose = Age X Adult dose

Age +12

Dose = 2/ 2+12 X 100Dose = 2/14 X 100Dose = 14. 28 mg/day

b) Formula for body weight: Dose = Body weight in kg X Adult dose 70 Dose = 20/70 X 50 Dose = 14.28 mg/day

c) Formula for Body surface area (BSA) in m2:

Dose = BSA X Adult dose 1.7

Dose = 2.1/1.7 X 25Dose = 30.88mg/day

UOS No. 3 Prescription for Systemic DiseaseQ.5 Write prescription for management of hypertension in 50 year old male with BP 180/90. The patient also has bronchial asthmaKeyMr. Ali50 YearsTownship Lahore

Rx Tablet Amlodipine 5mg1 Tablet once a day

Tablet Aspirin 150mg1 Tablet once a day

Q. 6 Write a prescription for a 40 year old female suffering from peptic ulcer associated with H.PyloriKeyMrs. Nazia Inayat30 YearsGarden Town, Lahore

RxTablet Clarithromycin 500mgOne tablet 3 times a day for 10 days

Tablet Metronidazole 400mgOne tablet three times a day for 14 days

Capsule Omeprazole 40mgOne capsule once a day for 4 weeks

UOS No. 4 Prescription for Microbial DiseaseQ. 7 Write a prescription for a 20 year old boy in emergency with high grade fever, chills and rigors at night for 2 days. Now malarial parasite smear is positive on peripheral blood filmKeyAli Naqvi20 yearsModel Town, Lahore

RxChloroquine Sulphate 250 mg4 tablets stat2 tablets after 6 hours1 Tablet 2 times a day for next 2 daysTablet ParacetamolTwo tablets three times a day

Q. 8 Write a prescription for 30 year old male with enteric fever for last 10 days.

KeyImtiaz Ahmed30 yearsMughalpura, Lahore

RxTablet ciprofloxacin 500 mgOne tablet 2 times a day for 14 days

Tablet Paracetamol2 Tablets three times a day

UOS No. 5 P-Drug for Systemic Disease

Q. 9 An obese male known Hepatitis B positive patient is having symptoms of polyuria and polydypsia uncontrolled by diet and exercise. Serum glucose is 300mg/dl. What is your P-Drug? What are alternate drugs?

Keya) Diagnosis: Non-Insulin Dependent Diabetes Mellitusb) Objective: Control of Blood Glucosec) Inventory of Group of Drugs for Treatment: Oral Hypoglycemics: Sulfonylureas, Biguanides,

Meglitinides, Thiazolidinediones and alpha glucosidase inhibitorsd) Choose subgroup: Biguanides because they cause anorexia and weight loss and they are cost

effectiveSulfonylureas cause weight gain; Thiazolidinediones avoided in patients with liver disease

e) P- Drug : Metforminf) Alternate Drugs: Alpha Glucosidase Inhibitors: Acarbose

Q. 10 A 50 year old insulin dependent male patient presented with moderate retro-sternal pain radiating to the left arm and left shoulder. It started when he was climbing the stairs. What is your P-Drug? What are alternate drugs?

Key a) Diagnosis: Classical Angina Pectorisb) Objective: Relief of the Pain of Anginac) Inventory of group of drugs for Treatment: Beta Blockers, Calcium channel blockers,

Nitrates and Nitrites and Potassium Channel Openersd) Choose A Sub-group: Nitrates and Nitrites: Most rapidly acting (through sublingual route)

and cost effectiveBeta Blockers not given in Insulin Dependent diabetics

e) Choose P Drug: Nitroglycerin (Again most cost-effectivef) Alternate Drugs: Isosorbide Dinitrate, Isosorbide Mononitrate, Calcium Channel Blocker

UOS No. 6 P-Drug for Microbial Disease

Q. 11 A young lady of 25 years reports to medical OPD with pain in the loins and dysuria. Urine examination shows numerous pus cells. X-ray KUB reveals no abnormality or stone in the urinary tract. What is your P Drug? What are alternate drugs?

Keya) Diagnosis: Uncomplicated Urinary Tract Infectionb) Objective: Treat the infectionc) Inventory of Groups of drugs for treatment: Anti-folates, Quinolones, Cephalosporins and

Aminoglycosidesd) Choose a subgroup: Anti-folates: most cost effectivee) Choose P Drug: Cotrimoxazolef) Alternate Drugs: A third generation cephalosporin or a fluoroquinolone like ciprofloxacin

Q. 12 A 30 year old male came to the doctors clinic with complaints of fever, abdominal pain and loose stools for the last 2 days. Stools contained blood and mucus. There is also history of cramps and tenesmus. What is your P Drug? What are alternate drugs?

Keya) Diagnosis: Bacillary Dysentryb) Objective: relief from the symptomsc) Inventory of group of drugs: Penicillins, Cephalosporins, Fluoroquinolones, Anti-folatesd) Choose Subgroup: Anti-folates (most cost-effective)e) Choose P Drug: Cotrimoxazolef) Alternate Drugs: Cephalosporins (Ceftriaxone), Fluoroquinolones

UOS No. 7 General Pharmacology

Q. 13 PharmacokineticsA 30 year old woman is diagnosed with tuberculosis. She is started on anti-tuberculosis treatment. After a few months, she becomes pregnant although she was taking oral contraceptives.Q. What happened? (1.5)Q. Name 3 other drugs that may cause similar oral contraceptive failure (1.5)

Key

She most probably was taking rifampin as part of the anti-tuberculosis treatment. This drug causes enzyme induction and hence increased the synthesis of enzymes responsible for metabolism of oral contraceptives, especially the estrogen component

Other drugs that may cause similar oral contraceptive failure include Phenytoin, Barbiturates like primidone and carbamazepine

Q. 14 PharmacodynamicsA patient is given a drug A and a response occurs. Next day he is given a drug B and a response occurs that is less than that of drug A.Q. Drug A and Drug B are what type of drugs? (1)Q. How will drug B behave in the presence of drug A? Explain (2)

Key Drug A is a full agonistDrug B is a partial agonist

Drug B will behave as an antagonist in the presence of Drug A as it will occupy many of the receptors and not allow the agonist to produce its full effect, i.e. hence the full agonist’s action will be antagonized

UOS No. 8 Autonomic Nervous System

Q. 15 Cholinergic SystemA farmer presents to the emergency department with vomiting, diarrhea, miosis, excessive salivation, excessive sweating, bronchial constriction, muscle weakness and convulsions

Q. What group of drug has the patient most probably taken? (1)Q. What is the drug treatment of his condition? (1)Q. What is ageing? (1)

KeyThe patient most probably has taken or has been exposed to an organophosphorous compound containing an irreversible cholinestrase inhibitorDrug treatment includes Atropine to counter the muscarinic effects, diazepam to control the convulsions and an Oxime like pralidoxime to regenerate the cholinestrase enzymeThe oximes have to be given before ageing starts otherwise, even they will be ineffective. Ageing is the breaking of one of the Oxygen-Phosphorus bonds of inhibitor (and thus a loss of alkyl group) which causes further strengthening of the Phosphorus-Enzyme bond.

Q. 16 Sympathetic SystemAn insulin dependent diabetic takes an anti-hypertensive drug and goes into hypoglycemic shock a few hours later

Q. What anti-hypertensive drug did he most probably take? (1)Q. Explain what happened (2)

Key He most probably took a beta blocker especially a one that does not have ISA.Such beta blockers are to be avoided in insulin dependent diabetics because:

Glycogenolysis is inhibited by Beta Blockers So there is decreased response of the body to hypoglycemia Plus symptoms of Hypoglycemia are masked i.e. Tachycardia and Tremors

UOS No. 9 CVS, Diuretics and Blood

Q. 17 DiureticsA patient who is taking medicine for bipolar disorder develops symptoms of polyuria and polydypsia. He is given a diuretic for the symptoms

Q. What group of diuretic was he given? Give example (1)Q. What is the rationale for using this diuretic in this condition? (2)

Key

He was given a thiazide diuretic for treatment of diabetes Insipidus caused by the drug lithium which is used for bipolar disorderExample is HydrochlorothiazideThe rationale for their use in this condition is that Thiazides decrease plasma volume---Decreased GFR------This causes enhanced Proximal reabsorption of NaCl and water—This Decreases delivery of fluid to the diluting segments—thus maximum volume of dilute urine that can be produced is decreased

Q. 18 CCFA known patient of CCF taking medicine for the problem develops severe bradycardia.

Q. What drug is he most likely taking (1)Q. What are the mechanisms of bradycardia caused by this drug? (2)

KeyHe is most likely taking Digoxin

Heart Rate is decreased (Negative Chronotropic Effect) due to: a) Vagal Action (Blocked by atropine)

Direct stimulation of vagal nucleus Sensitization of the carotid baroreceptors Increased sensitivity of muscarinic receptors to Ach

b) Direct Action (Cannot be reversed by atropine) In CCF the sympathetic activity is increased due to compensatory mechanisms Digoxin, by improving the circulation decreases the sympathetic response and thus

decreases the heart rate

UOS No. 10 Respiratory System

Q. 19 A 30 year old male comes to the emergency department with complaint of cough, dyspnoea and wheezing. He has history of similar episodes off and on.

Q. What is the most appropriate drug for the treatment of this patient? (1)

Q. What is the most common adverse effect caused by this drug during treatment? Explain this adverse effect. (2)

Key

A beta 2 agonist like salbutamol given by nebuliser would be most appropriateTachycardia; although it is a beta 2 agonist, it is not absolutely selective like all drugs and will cause some tachycardia and even more with higher doses

Q. 20 A 30 year old male is diagnosed to be HIV positive. He is receiving anti-viral therapy.

Q. Which drug is indicated to protect him against pneumonia due to pneumocystitis jiroveci?(1)

Q. Enumerate the adverse effects of this drug (2)

KeyCotrimoxazoleHypersensitivity reactions, crystalluria, Hematopoietic disturbances like Agranulocytosis, thrombocytopenia causing petechiae, hematuria and epistaxis and rarely aplastic anemia, KernicterusOther adverse effects include stomatitis, conjunctivitis, and rarely polyarteritis nodosa, confusion, ataxia, tinnitus and psychosis

UOS No. 11 GIT

Q. 21 A patient with complaint of persistent vomiting was given a drug. After some time he develops uncontrolled restlessness and spastic movements of parts of the body.

Q. What group of anti-emetic was he given? Give example of such a drug (1)

Q. What is the cause and treatment of these symptoms? (2)

KeyA D2 receptor blocker like metoclopramideThese are extrapyrimidal symptoms caused by the block of dopaminergic pathway Nigrostriatal pathway involved in control of voluntary movementThese can be treated by giving a centrally acting anti-muscarinic like benztropine that will restore the balance between acetylcholine and dopamine

Q. 22 A patient with chronic low back ache has been taking “pain killers” for long time. He now complains of epigastric pain, vomiting and dyspepsia.

Q. Which type of drugs could have caused these complaints? (1)

Q. What is the treatment of the symptoms? (2)

Key NSAIDS (Non-steroidal anti-inflammatory drugs)Misoprostol is used for prevention of such ulcers; it has less role in treatmentProton pump inhibitors are used for the treatment of such ulcers. H2 receptor blockers are also used

UOS No. 12 Autacoids

Q. 23 A patient with significant postpartum hemorrhage is given oxytocin but it is ineffective in controlling the bleeding. Another drug was given which was effective but caused significant nausea and vomiting.

Q. What drug was given to control the bleeding? (1)

Q. What is the cause of the nausea and vomiting by this drug? (1)

Q. What may be the complications of over dosage of this drug? (1)

Key

Ergonovine (ergometrine) was givenThe nausea and vomiting are caused by stimulation of the vomiting center in CNSOver dosage may cause severe prolonged vasoconstriction that may result in ischemia and gangrene

Q. 24 A patient is given a drug orally for the treatment of glaucoma that has no effects on autonomic system and does not cause acid base disturbance.

Q. What group of drugs was he given? Name any drug of this group (1.5)

Q. What is the mechanism of action of this drug in treating glaucoma? (1.5)

KeyHe was given Prostaglandin analog like Latanoprost

This drug increases the outflow of aqueous humor