To The Controller Of Examinations University Of Health Sciences Lahore

To The Controller of Examinations University of Health Sciences Lahore Subject: Model OSPE (Objectively Structured Performance Evaluation) Questions of Pharmacology for 2nd 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 & Therapeutics Lahore Medical & Dental College Lahore

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, Anticholinergics, sympathomimetics and local anesthetics) 2. To Identify the group of the unknown drug by demonstrating its effects on Rabbit’s eyes 3. To Draw a simple dose response curve of Acetylcholine’s effects on rabbit’s ileum 4. To demonstrate competitive antagonism between Acetylcholine and Atropine by observing their actions on rabbit’s ileum 5. To demonstrate the effects of different drugs (Propranolol, Adrenaline, Acetylcholine and Atropine) on frog’s heart 6. 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 frog 8. 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/Student Faulty experimental set-up of organ bath Key for Examiner Students shall be assessed whether they have checked the following on a faulty experimental set-up S. No 1 2 3 4 5 6

Assess Proper Oxygenation Proper temperature of Organ Bath Balanced lever with Plastocine etc Proper placing of clamps Tyroid’s Solution and writing pen (Present) Proper Placement of Tissue

Marks 1 1 1 1 1 1

Q 2. Identify the group of the unknown drug by observing its effects on Rabbit’s eyes Requirements for Organizer/Student Unknown Drug Rabbit (Unknown drug has already been instilled into one eye) Torch Cotton Wool Scale Key for Examiner Students shall be assessed for performing the following: S. No 1 2 3 4 5 6

Assess/Perform Measure the size of the pupil of rabbit’s eyes (initial size before drug was added will be told) Perform light reflex on rabbit’s eyes Perform corneal reflex on rabbit’s eyes Note the colour of conjunctiva of rabbit’s eyes Identify possible group of the unknown drug Give specific examples of unknown drug

Marks 1 1 1 1 1 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/Student Acetylcholine Solution of strength 10-3, 10-4, 10-5 and 10-6 solutions Different reagents for preparation of Tyroid’s solution and Ringer’s solution Apparatus (Flasks, beakers, test tubes etc) Key for Examiner S. No 1 2 3 4 5 6

Assess/Perform Prepare 10-4 strength solution from 10-3 Acetylcholine Take 1 μg of ACH from 10-5 and/or 10-6 solutions Choose the correct chemicals for preparation of Tyroid’s Solution Prepare 1 Liter of Tyroid’s solution using correct measurements of chemicals Choose the correct chemicals for preparation of Ringer’s solution Prepare 1 Liter of Ringer’s solution using correct measurements of chemicals

Marks 1 1 1 1 1 1

Q. 4 Record Contractions and Obtain Simple Dose Response Curve of Acetylcholine on Rabbit’s Ileum Requirements for Organizer/Student Experimental setup of Organ Bath with Rabbit’s Ileum as tissue Key for Examiners S. No 1 2 3 4 5 6

Assess/Perform Take Baseline Reading Add next dose of Acetylcholine Take reading after specific time Wash the preparations after specific times Know how to draw a dose response curve from a set of readings Give Significance of Log-dose response curve

Marks 1 1 1 1 1 1

Q. 5 Demonstrate the effects of the Given Drugs on Frog’s Heart Requirements for Organizer/Student Experimental setup of Frog’s Heart with Kymograph Drugs to be administered (Adrenaline, Propranolol, Acetylcholine and Atropine) Key for Examiners S. No 1 2 3 4 5 6

Assess/Perform Take a baseline reading Add a dose of Given agonist drug Record contractions Wash, take baseline and add antagonist and record contractions Record contractions of antagonist followed by agonist Give explanation for above reading

Marks 1 1 1 1 1 1

Q. 6 Take Data of BP/Pulse of simulated subjects and Calculate Biostatistical Values Requirements for Organizer/Student BP apparatus Simulated subjects t table charts Key for Examiners S. No 1 2 3 4 5 6

Assess/Perform Take the BP/Pulse of 6 subjects before and after exercise Calculate the means of observations Calculate the standard deviations Calculate the Standard error of the means Calculate the t value Find out the P Value from Given t table charts and Give significance of its value

Marks 1 1 1 1 1 1

Q. 7 Determine reflex times of frog after application of various drugs Requirements for Organizer/Student Experimental setup for practical of Reflex time of frog Injections Caffeine, Diazepam and Lignocaine Key for Examiners S. No 1 2 3 4 5 6

Assess/Perform Take normal reflex time Apply Lignocaine and note reflex time Inject caffeine and note reflex time Inject diazepam and note reflex time Inference of above readings Explain above inference

Marks 1 1 1 1 1 1

Q. 8 Demonstrate competitive antagonism between Acetylcholine and Atropine Requirements for Organizer/Student Experimental Setup of dose response curve of acetylcholine Acetylcholine solutions of different strengths Atropine solutions of different strengths Key for examiners A 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 1 2 3 4 5 6

Assess/Perform Take submaximal dose or next dose of Acetylcholine and a dose of atropine Record contractions Continue by increasing dose of Acetylcholine while keeping dose of atropine constant Students should know when to stop Draw dose response curve of agonist in presence of antagonist Show effect of shift of curve (Right parallel shift)

Marks 1 1 1 1 1 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 Key a) 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 wastage a) To calculate the amount of Phenobarbitone For one powder, Phenobarbitone required = 30mg For 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 mg To make 120 mg we add a diluent i.e. lactose So minimum weight of one powder =120 mg Minimum weight of six powders = 120 X 6 = 720mg Amount 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 kinetics Drug B is undergoing zero order kinetics Give presumptive calculations of their plasma concentrations after different times (initial plasma concentration is 100mg/dl for both Key Time 0 Hours 4 Hours 8 Hours 12 Hours 16 Hours

Drug A (mg/dl) 100 50 25 12.5 6.25

Drug B (mg/dl) 100 80 60 40 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 Age +12

X Adult dose

Dose = 2/ 2+12 X 100 Dose = 2/14 X 100 Dose = 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 25 Dose = 30.88mg/day

UOS No. 3 Prescription for Systemic Disease Q.5 Write prescription for management of hypertension in 50 year old male with BP 180/90. The patient also has bronchial asthma Key Mr. Ali 50 Years Township Lahore Rx Tablet Amlodipine 5mg 1 Tablet once a day Tablet Aspirin 150mg 1 Tablet once a day Q. 6 Write a prescription for a 40 year old female suffering from peptic ulcer associated with H.Pylori Key Mrs. Nazia Inayat 30 Years Garden Town, Lahore Rx Tablet Clarithromycin 500mg One tablet 3 times a day for 10 days Tablet Metronidazole 400mg One tablet three times a day for 14 days Capsule Omeprazole 40mg One capsule once a day for 4 weeks UOS No. 4 Prescription for Microbial Disease Q. 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 film Key Ali Naqvi 20 years Model Town, Lahore Rx Chloroquine Sulphate 250 mg 4 tablets stat 2 tablets after 6 hours 1 Tablet 2 times a day for next 2 days Tablet Paracetamol Two tablets three times a day

Q. 8 Write a prescription for 30 year old male with enteric fever for last 10 days. Key Imtiaz Ahmed 30 years Mughalpura, Lahore Rx Tablet ciprofloxacin 500 mg One tablet 2 times a day for 14 days Tablet Paracetamol 2 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 PDrug? What are alternate drugs? Key a) Diagnosis: Non-Insulin Dependent Diabetes Mellitus b) Objective: Control of Blood Glucose c) Inventory of Group of Drugs for Treatment: Oral Hypoglycemics: Sulfonylureas, Biguanides, Meglitinides, Thiazolidinediones and alpha glucosidase inhibitors d) Choose subgroup: Biguanides because they cause anorexia and weight loss and they are cost effective Sulfonylureas cause weight gain; Thiazolidinediones avoided in patients with liver disease e) P- Drug : Metformin f) 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 Pectoris b) Objective: Relief of the Pain of Angina c) Inventory of group of drugs for Treatment: Beta Blockers, Calcium channel blockers, Nitrates and Nitrites and Potassium Channel Openers d) Choose A Sub-group: Nitrates and Nitrites: Most rapidly acting (through sublingual route) and cost effective Beta Blockers not given in Insulin Dependent diabetics e) Choose P Drug: Nitroglycerin (Again most cost-effective f) 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? Key a)

b) c)

d) e) f)

Diagnosis: Uncomplicated Urinary Tract Infection Objective: Treat the infection Inventory of Groups of drugs for treatment: Anti-folates, Quinolones, Cephalosporins and Aminoglycosides Choose a subgroup: Anti-folates: most cost effective Choose P Drug: Cotrimoxazole 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? Key a) b) c) d) e)

Diagnosis: Bacillary Dysentry Objective: relief from the symptoms Inventory of group of drugs: Penicillins, Cephalosporins, Fluoroquinolones, Anti-folates Choose Subgroup: Anti-folates (most cost-effective) Choose P Drug: Cotrimoxazole f) Alternate Drugs: Cephalosporins (Ceftriaxone), Fluoroquinolones

UOS No. 7 General Pharmacology Q. 13 Pharmacokinetics A 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 Pharmacodynamics A 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 agonist Drug 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 System A 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? Q. What is the drug treatment of his condition? Q. What is ageing?

(1) (1) (1)

Key The patient most probably has taken or has been exposed to an organophosphorous compound containing an irreversible cholinestrase inhibitor Drug treatment includes Atropine to counter the muscarinic effects, diazepam to control the convulsions and an Oxime like pralidoxime to regenerate the cholinestrase enzyme The 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 System An 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? Q. Explain what happened

(1) (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 Diuretics A 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 Q. What is the rationale for using this diuretic in this condition?

(1) (2)

Key He was given a thiazide diuretic for treatment of diabetes Insipidus caused by the drug lithium which is used for bipolar disorder Example is Hydrochlorothiazide The 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 CCF A known patient of CCF taking medicine for the problem develops severe bradycardia. Q. What drug is he most likely taking Q. What are the mechanisms of bradycardia caused by this drug?

(1) (2)

Key He 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 appropriate Tachycardia; 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) Key Cotrimoxazole Hypersensitivity reactions, crystalluria, Hematopoietic disturbances like Agranulocytosis, thrombocytopenia causing petechiae, hematuria and epistaxis and rarely aplastic anemia, Kernicterus Other 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)

Key A D2 receptor blocker like metoclopramide These are extrapyrimidal symptoms caused by the block of dopaminergic pathway Nigrostriatal pathway involved in control of voluntary movement These 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 treatment Proton 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 given The nausea and vomiting are caused by stimulation of the vomiting center in CNS Over 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) Key He was given Prostaglandin analog like Latanoprost This drug increases the outflow of aqueous humor