Question bank on General Pharmacology

For students of 2^nd Prof. MBBS

Pharmacokinetics

1. Definition of Drug. Difference between drug and medicine.

2. Different routes of drug administration, their advantages and disadvantages, examples of each route.

3. Define Pharmacokinetics. How does it differ from Pharmacodynamics?

4. Write short notes on:

a) Passive transport of drugs

b) Absorption of drug

c) Plasma protein binding of drug and its significance

d) Apparent volume of distribution and its significance. Why is it called “apparent”?

e) Blood brain barrier and its pharmacological significance

f) Biotransformation and its two phases

g) Microsomal enzymes, their inducers and inhibitors

h) Cytochrome P-450

i) Bioavailibility of a drug, Calculation, Significance

j) Half life of a drug, types, calculation, significance

k) Clearence and its pharmacological significance

l) Steady state plasma concentration of a drug

Pharmacodynamics and adverse drug reaction

1. Define pharmacodynamics.

2. Mechanisms of drug action.

3. Define: Agonist, antagonist and partial agonist. What is Inverse agonist?

4. Short notes on:

a) Therapeutic Index

b) Therapeutic window

c) Tolerance

d) Tachyphylaxis

e) Effects of drug combinations

f) Types of antagonism

g) Pharmacogenetics

h) Teratogenic drugs

i) Side effect vs. Secondary effects

j) Idiosyncrasy

k) P-drugs

l) Essential drugs

m) Orphan drugs

Laboratory diagnosis of Generalised Edema (Anasarca)

Edema is defined as collection of excess fluid in tissue space or serous cavities. Generalised edema is also called Anasarca.

Common causes of anasarca are:

• a.       Renal disease – Nephrotic syndrome
• b.      Hepatic disease – Cirrhosis of Liver
• c.       Cardiac disease – Congestive cardiac failure

Investigations:

Baseline:

• a.       Complete hemogram
• b.      Blood Sugar, Urea, Creatinine
• c.       Chest X ray – PA view
• d.      ECG in 12 leads

Special:

• a.       Echocardiography
• b.      Serum albumin
• c.       LFTs
• d.      Prothombin time
• e.      Urine R/E
• f.        24 hour urinary protein excretion
• g.       Examination of effusion/ ascitic fluid

Complete hemogram

• ·         Hb – may be reduced in chronic renal disease
• ·         RBCs may show macrocytosis or target cells in chronic liver disease

Blood sugar

• ·         To rule out Diabetes Mellitus

Urea/ Creatinine

• ·         May rise in Renal disorder and left Heart failure

Chest X Ray

• ·         May show evidence of pulmonary edema (bat wing appearance of hilar region)
• ·         May show evidence of Pleural and Pericardial effusion (due to hypo-albuminemia)
• ·         May show cardiac hypertrophy in chronic heart diseases

ECG in 12 leads

• ·         Shows patterns of Ventricular hypertrophy
• ·         Gives early evidence of electrolyte disbalance (in renal failure)

Echocardiography

• ·         Confirms heart failure (LV ejection fraction < 55%)
• ·         Detects ventricular hypertrophy
• ·         Detects pericardial effusion

Serum albumin

• ·         Reduced in hepatic disease and nephrotic syndrome
• ·         Unchanged in heart failure

Liver function tests

• ·         Abnormal in cirrhosis (raised AST, ALT, reduced albumin, altered albumin:globulin ratio)

Prothrombin time

• ·         Raised in cirrhosis
• ·         Reduced in nephrotic syndrome
• ·         Unchanged in cardiac failure

Urine Routine Examination

In nephrotic syndrome, following changes are expected:

• ·         Physical – appearance is hazy, high specific gravity
• ·         Chemical – protein +++
• ·         Microscopic – fatty cast +, hyaline cast +++

24 hour urinary protein excretion

• ·         Raised in nephrotic syndrome (often > 3.5 g/day)

Examination of pleural fluid in case of pleural effusion

·         State the differences between transudate and exudate (from your textbook/ copy)

DIAGNOSIS OF SEPTICEMIA

Causative organisms:

(Mention those bacteria that you are well-conversant with)

Gram negative cocci – meningococci, gonococci, hemophilus
Gram negative bacilli – Salmonella typhi, EIEC, almost all causes of UTI, Infective endocarditis (including HACEK organisms), meningitis.
Gram positive organisms (rare) – Streptococcus, Staphylococcus, Pneumococcus, almost all organisms that cause osteomyelitis and pneumonia.

Material for diagnosis:

Venous blood – 3 samples at 0, 30 and 90 min intervals from admission
Urine
CSF (if features of meningeal irritation are present)
Swab from suspected skin lesion


Steps of diagnosis:
Exams and Tests

Physical examination may show:

Low blood pressure
Low body temperature or fever
Signs of associated disease (such as meningitis, epiglottitis, pneumonia, or cellulitis)

Tests that can confirm infection include:
Blood culture
Urine culture
CSF culture
Culture of any suspect skin lesion
CBC
Platelet count
Clotting studies
PT
PTT
Fibrinogen levels
Blood gases

BLOOD CULTURE
A minimum of 10 ml of blood is taken through venipuncture and injected into two or more "blood bottles" with specific media for aerobic and anaerobic organisms.
Care needs to be taken that the bottles are not contaminated with bacteria from staff members or other patients. To that end, the patient's skin is rubbed or sprayed with denaturated alcohol and betadine applied to the sampling site. Sterile gloves should be used to minimize contamination.
To maximise the diagnostic yield of blood cultures multiple sets of cultures (each set consisting of aerobic & anaerobic vials filled with 3-10 mL) may be ordered by medical staff.
Set 1= L. antecubital fossa at 0 minutes
Set 2= R. antecubital fossa at 30 minutes
Set 3= L. or R. antecubital fossa at 90 minutes
Ordering multiple sets of cultures increases the probability of discovering a pathogenic organism in the blood and reduces the probability of having a positive culture due to skin contaminants.
After inoculating the culture vials on the hospital floor, they are sent to the microbiology lab clinical pathology department. Here the cultures are entered into a blood culture machine, which keeps the samples at body temperature. The blood culture instrument reports positive blood cultures (cultures with bacteria present, thus indicating the patient is "septic") by monitoring carbon dioxide levels produced by bacteria in the vials via fluorescence detected by a light emitting diode (LED). Most cultures are monitored for 5-days, after which, if the vials are negative, they are removed.
If a vial is positive, a microbiologist will perform a Gram Stain on the blood for a rapid, general ID of the bacteria, which they will report to the attending physician of the septic patient. The blood is also subcultured or "Subed" onto agar plates to isolate the pathogenic organism for culture and suceptability testing, which takes up to 3 days time. This culture & sensitivity (C&S) process IDs the species of bacteria. Antibiotic sensitivities are then assessed on the isolate to inform clinicians on appropriate antibiotics for treatment.
Some guidelines for infective endocarditis recommend taking up to 6 sets of blood for culture (around 60 ml).

URINE EXAMINATION:
(Summarize the Laboratory diagnosis for UTI)
CSF EXAMINATION:
(Summarize the Laboratory diagnosis of Meningitis)

ROUTINE EXAMINATIONS
CBC - may show neutrophilia (enteric fever may show neutropenia)
Platelet count - may decrease following DIC
Clotting studies
PT - may rise following DIC r hepatocellular failure
PTT - may rise in DIC
Fibrinogen levels – may be low in DIC
FDP – may rise in DIC
Blood gases – may be abnormal in respiratory failure (raised pCO2 and low pO2)

CONCLUSION:
Based on the above investigations we can reach a diagnosis of septicemia.

SUBARACHNOID HEMORRAGE - LABORATORY WORK UPS AND FINDINGS

Subarachnoid hemorrhage (SAH) implies the presence of blood within the subarachnoid space from some pathologic process. The common medical use of the term SAH refers to the nontraumatic types of hemorrhages, usually from rupture of a berry aneurysm or arteriovenous malformation (AVM). The scope of this article is limited to these nontraumatic hemorrhages.

Workup
Complete blood count
Prothrombin time, activated partial thromboplastin time
Blood typing and screening
Blood bank typing is indicated when SAH is identified or a severe bleed is suspected.
Intraoperative transfusions may be required.
Troponin I (cTnI): cTnI measurement is a powerful predictor for the occurrence of pulmonary and cardiac complications, but it does not carry additional prognostic value for clinical outcome in patients with aneurysmal SAH (Schuiling, 2005).
Imaging Studies
The initial study of choice is an urgent CT scan without contrast (see Picture 1).
Sensitivity decreases with time from onset and with older resolution scanners.
In one recent study published by New England Journal of Medicine, good quality CT scanning revealed subarachnoid hemorrhage in 100% of cases within 12 hours of onset and 93% within 24 hours of onset (Suarez, 2006). Other studies traditionally report 90-95% sensitivity within 24 hours of onset of bleeding, 80% at 3 days, and 50% at 1 week.
CT also can detect intracerebral hemorrhage, mass effect, and hydrocephalus.
A falsely negative CT scan can result from severe anemia or small-volume SAH.
Distribution of SAH can provide information about the location of an aneurysm and prognosis.
Intraparenchymal hemorrhage may occur with middle communicating artery and posterior communicating artery aneurysms. Interhemispheric and intraventricular hemorrhages may occur with anterior communicating artery aneurysms.
Outcome is worse for patients with extensive clots in basal cisterns than for those with a thin, diffuse hemorrhage.
Cerebral angiography is performed once the SAH diagnosis is made.
This study assesses the following:
Vascular anatomy
Current bleeding site
Presence of other aneurysms
This study helps plan operative options.
Angiography findings are negative in 10-20% of patients with SAHs.
If negative, some advocate repeating angiography a few weeks later.
Magnetic resonance imaging (MRI) is performed if no lesion is found on angiography.
Its sensitivity in detecting blood is considered equal or inferior to that of CT scan.
The higher cost, lower availability, and longer study time make it less optimal for detecting SAH.
MRI mostly is used to identify possible AVMs that are not visible on angiography.
MRI may miss small symptomatic lesions that have not yet ruptured.
Magnetic resonance angiography (MRA) is less sensitive than angiography in detecting vascular lesions; however, many believe CT angiography and/or MRA one day will play a more central role.
Multidetector computed tomography angiography (MD-CTA) of the intracranial vessels is now a routine examination, and it is becoming fully integrated into the imaging and treatment algorithm of patients presenting with acute subarachnoid hemorrhage in many centers in the United Kingdom and Europe (Goddard, 2005). Digital-subtraction cerebral angiography has been the criterion standard for the detection of cerebral aneurysm, but CT angiography has gained more popularity and is frequently used owing to its noninvasiveness and a sensitivity and specificity comparable to that of cerebral angiography (Jayaraman, 2004).
Other Tests
Electrocardiogram
About 20% of SAH cases have myocardial ischemia from the increased circulation of catecholamines.
Typical results are nonspecific ST-and T-wave changes, prolonged QRS segments, U waves, and increased QT intervals.
ECG changes reflect myocardial ischemia or infarction and should be treated in the usual manner. Suspicion of SAH is a contraindication to thrombolytic and anticoagulant therapy.

Lumbar puncture
Lumbar puncture (LP) is indicated if the patient has possible SAH and negative CT scan findings.
Perform CT scan prior to LP to exclude any significant intracranial mass effect or obvious intracranial bleed.
LP may be negative less than 2 hours after the bleed; LP is most sensitive at 12 hours after symptom onset.
Red blood cells (RBCs) in the cerebrospinal fluid (CSF) remain consistently elevated in 2 sequential tubes or punctures in SAH, whereas the number of RBCs in technically traumatic punctures decrease over time.
Xanthochromia (yellow-to-pink CSF supernatant) usually is seen by 12 hours after the onset of bleeding; ideally this is measured spectrographically, although many laboratories rely on visual inspection.
LP findings were thought to be positive in 5-15% of all SAH presentations that are not evident on the CT scan. This number may be no longer valid with the advent of newer generations of CT scans. A recent small retrospective chart review about patients presenting to the emergency department undergoing fifth generation CT scans and LP showed no patients with positive LP and negative CT scan (Boesiger, 2005).

REFERENCE: http://emedicine.medscape.com/article/794076-overview

PHARMACOLOGY MOCK TEST

Full marks 40 Time – 2 hours

Attempt all questions. Supplement your answer with charts and diagrams as needed.

1. Name the drugs that can be administered by rotahaler. What is the basic difference between a rotahaler and a metered dose inhaler (MDI)? What are the advantages and disadvantages of nebuliser over MDI? Discuss the management of acute severe asthma indicating the doses of individual drugs. [2 + 1 + 2 + 5]

Or, Classify β adrenoceptor antagonists. State the contraindications of non-selective β adrenoceptor antagonists. What is the role of β blockers in AMI? Name the drugs used in the management of hypertension in pregnancy with their doses. [3 + 2 + 2 + 3]

2. Explain why: (Any FIVE) [2 x 5]

a) Neostigmine is preferred over Physostigmine for the treatment of myasthenia gravis
b) Omeprazole is not given concurrently with antacids
c) Spironolactone is used in cirrhosis of liver
d) Atropine substitutes are used in Haloperidol induced acute dystonias
e) Acetazolamide should be avoided in hepatic failure
f) Enalapril is contraindicated in bilateral renal artery stenosis
g) Class III anti-arrhythmic drugs can themselves precipitate arrhythmias
h) Pirenzepine is not used in treatment of peptic ulcer

3. Describe the mechanism of action of: (Any 4) [2 x 4]

a) Castor oil as purgative
b) Adenosine in PSVT
c) Ketotifen in asthma
d) Thiazide in diabetes insipidus
e) Glucocorticoids in chemotherapy induced vomiting
f) Pralidoxime in organophosphate compound poisoning
g) Propranolol in hyperthyroidism

4. Write short notes on: [4 x 3]

a) Management of acute angle closure glaucoma OR Management of mushroom poisoning
b) Classification of drugs used in diarrhea OR Classification of drugs used in peptic ulcer
c) Glyceryl trinitrate OR Digoxin (Mechanism of action, Use, Dose, Adverse effect)

Mock test on Bacteriology (General and Systemic)

MICROBIOLOGY (BACTERIOLOGY) MOCK TEST

Full marks 40 Time – 2 hours

Attempt all questions. Supplement your answer with charts and diagrams as needed.

1. A middle aged lady attended the skin OPD with complaints of hypopigmented patch over the right elbow with progressive loss of sensation. What is your provisional diagnosis? How would you proceed to confirm the clinical diagnosis in the laboratory? How is the efficacy of treatment evaluated in such cases? [1 + 7 + 2]

Or, A middle aged person attended the STD clinic with a solitary painless ulcer with hard base on the glans penis. What is the commonest organism that causes such a lesion? What are the methods of isolation and demonstration of the organism in the laboratory? Discuss the role of serological tests in diagnosing late stages of the disease. [1 + 4 + 5]

Or, Name the bacteria responsible for diarrheal diseases in man. How would you proceed to investigate a case of bacterial diarrhea in the laboratory if you are supplied with the fresh fecal matter of the infected individual collected in a sterile plastic bottle? [2 + 8]

2. Write short notes on any THREE: [3 x 4 = 12]

a) Acid fast stain OR Bacterial growth curve
b) Plasmids OR Bacterial flagella
c) El Tor Vibrio OR Shiga toxin producing E. coli
d) Importance of ASO titer OR Interpretation of Mantoux test

3. Comment on any THREE: [3 x 4 = 12]

a) The choice of specimen for diagnosis depends on the stage of Enteric fever.
b) Koch’s postulates have many exceptions.
c) Morphology of the colonies of motile bacteria depends on the concentration of agar agar in Nutrient agar medium.
d) Bacteriological profile of purulent meningitis varies with the age of the patient.
e) Slide and tube coagulase tests are based on different biological principles.
f) Both chromosomal and extra-chromosomal factors are involved in the origin of bacterial drug resistance.

4. Differentiate between any THREE: [3 x 2 = 6]

a) Staphylococcus aureus and S. saprophyticus
b) Autoclaving and Tyndallisation
c) Streptococcus pneumoniae and Streptococcus pyogenes
d) Chlamydia and bacteria
e) Blood agar and chocolate agar

Mock test on Pathology Paper I

PATHOLOGY PAPER I

Full marks 40 Time – 2 hours

Attempt all questions. Supplement your answer with charts and diagrams as needed.

Group A

1. A 30 year old lady presented with multiple petechial spots on skin and easy bruisability for the last one year. On examination, temperature, pulse and BP were within normal limits. How would you proceed to investigate the case in the laboratory? [10]

Group B (Answer any ONE)

2. Classify Diabetes Mellitus according to causes. What are the acute complications of DM? Enumerate the investigations that you may use to evaluate the glycemic control in a patient of DM who is under treatment. Discuss the diagnostic importance of oral glucose tolerance test. [3 + 2 + 2 + 3]

3. Classify acute leukemia based on bone marrow findings and cytochemistry. What may be the causes of dry tap in acute leukemia? Enumerate the clinical conditions caused by organ infiltration in acute leukemia. [5 + 2 + 3]

Group C (Answer any ONE)

4. Discuss the various routes of spread of a malignant tumor. Name 4 occupational cancers with their associated occupations. Name 4 premalignant conditions and their resultant cancers. Name 4 tumors that can present with Cushing’s syndrome.
[4 + 2 + 2 + 2]

5. Discuss the steps of healing of a clean surgical incision well apposed by sutures. Mention four complications that may develop due to infection of the surgical wound. Discuss the pathogenesis of septic shock. [4 + 2 + 4]

Group D

6. Write short notes on: (Any FIVE) [5 x 2]

a) Peripheral blood picture in vitamin B-12 deficiency
b) Myeloid leukemoid reaction
c) Plummer Vinson syndrome
d) Target cells
e) Staining of amyloid
f) Turner’s syndrome
g) Reed Sternberg cells