Parmacology: AIIMS MAY 2014

Q-1. Which of the following anti-Parkinson drug may cause peripheral vasospasm?
a) Ropinirole
b) Amantadine
c) Bromocriptine
d) Carbidopa

Answer: Bromocriptine
Bromocriptine is a dopamine receptors agonist that may cause peripheral vasospasm. It is contraindicated in patients with peripheral vascular disease.
Ropinirole directly stimulate the dopamine receptors but it doesn’t cause vasospasm.
Amantadine and Carbidopa do not act directly act on dopamine receptors.

Q-2. Lithium should be stopped how many days before surgery
a) 1
b) 2
c) 3
d) 4

Answer: 1 day
Lithium is used to treat bipolar affective disorders.
It may potentiate the effect of non-depolarizing neuromuscular blocking agents.
The clearance of lithium can be reduced and its toxicity increased by factors that cause negative fluid balance, negative sodium balance, and decreased glomerular filtration rate.
Plasma half life of lithium is 20 hours.
Lithium should be discontinued 1 day before major surgery and resumed when renal function and electrolyte levels are stable.
If serum levels are not in a toxic range, renal function is normal, and fluid electrolyte status is stable, lithium can be continued before minor surgery.

Q-3. ATT side effects as hypothyroidism
a) INH
b) Pyrazinamide
c) Ethionamide
d) Streptomycin

Answer: Ethionamide
Ethionamide is second-line anti-tuberculosis medication. Ethionamide is administered at a dose of 15–20 mg/kg/day (maximum 1 g/day) once or twice/day.
Ethionamide use is most commonly limited by gastrointestinal intolerance. Taking ethionamide at bedtime or with food may improve tolerance.
Hypothyroidism is an important adverse event; therefore, thyroidstimulating hormone levels should be measured at baseline and monthly while patients are receiving therapy.
Hepatotoxicity can also occur with ethionamide; therefore, baseline liver function tests should be obtained.

Q-4. Methacholine agonist at
a) M2
b) M1
c) M4
d) M3

Answer: M2
Agonist of muscarinic receptors:
M2- Methacholine
M3- Bethanechol

Q-5. Frusemide acts on which part of
loop of Henle?
a) Ascending limb
b) Descending limb
c) PCT
d) DCT

Answer: Ascending limb
The diuretics are generally divided into four major classes, which are distinguished by the site at which they impair sodium re-absorption:
Loop diuretics act in the thick ascending limb of the loop of Henle
Thiazide-type diuretics in the distal tubule and connecting segment
Potassium-sparing diuretics in the aldosterone-sensitive principal cells in the cortical collecting tubule
Acetazolamide and mannitol act at least in part in the proximal tubule.

Q-6. Chronic laxative use can lead to-
a) Hypo-magnesemia
b) Hypo-kalemia
c) Hypoglycemia
d) Spasm of colon

Answer: Hypo-kalemia
Laxatives are generally well tolerated and may be considered safe drugs. When taken at much higher than the recommended doses (laxative abuse) some side effects may occur (e.g. hypo-kalemia, metabolic alkalosis, renal tubular damage).

Q-7. Which does not form active metabolites?
Which is not a pro-drug?
a) Diazepam
b) Cyclophosphamide
c) Lisinopril
d) Fluoxetine

Answer: Lisinopril
Captopril and Lisinopril are active drugs and other ACE inhibitors are inactive pro-drugs until metabolized in the liver.
Enalpril is an oral pro-drug that is converted to enalprilat. Lisinopril is a lysine derivative of enalprilat.
When hypertension or heart failure fails to respond adequately to a pro-drug ACE inhibitor, we should consider a trial of Captopril or Lisinopril.
Liver disease may impair activation of pro-drugs. This may apply to liver congestion due to heart failure or hypertension.
Fosphenytoin is a more stable phosphate pro-drug of phenytoin.

Q-8. Alpha 2 agonist causes a/e
a) Anxiolysis
b) Sedation
c) Analgesia
d) Hyperalgesia

Answer: Hyperalgesia
The alpha-2 (α2) adrenergic receptor is a G protein-coupled receptor (GPCR). Catecholamines like nor-epinephrine (nor-adrenaline) and epinephrine (adrenaline) signal through the α2-adrenergic receptor in the central and peripheral nervous systems.
Alpha-2 agonists provide sedation, analgesia, muscle relaxation and anxiolysis.

Q-9. Methadone related false statements-
a) Used in chronic treatment of pain
b) Mu agonist
c) Alpha agonist
d) None

Answer: Alpha agonist
Methadone is a synthetic opioid analgesic that is primarily a mu-opioid agonist.
Methadone is also used as part of the treatment of dependence on opioid drugs, although prolonged use of methadone itself may result in dependence.
Indications: For the treatment of dry cough, drug withdrawal syndrome, opioid type drug dependence, and pain

Q-10. All true about midazolam except-
a) Antero-grade amnesia
b) Retrograde amnesia
c) Tachyphylaxis seen in patients receiving large doses
d) Less Cardiovascular risk in comparison to propofol

Answer: Retrograde amnesia
Midazolam is a short-acting but quickly effective benzodiazepine drug.
Midazolam has very powerful anxiolytic (anti-anxiety), amnestic, hypnotic, anticonvulsant, skeletal muscle relaxant, and sedative effects.
Because it is amnestic, rapidly reaches therapeutic plasma levels, and has a short half-life of only 2-6 hours midazolam is considered optimal for relieving anxiety, sedating patients and causing anterio-grade amnesia in preoperative situations.
Tolerance and tachyphylaxis (an acute decrease in the response to a drug after its administration) may occur, particularly with longer-term infusions.
Benzodiazepine withdrawal syndrome has also been associated with high dose/long-term midazolam infusions.
Compared with propofol infusions, midazolam infusions have been associated with a decreased occurrence of hypotension.
Lorazepam is a more cost-effective choice for long-term sedation.

Q-11. Least emetogenic drugs used in cancer chemotherapy
a) Cisplatin
b) Doxorubicin
c) Daunorubicin
d) Chlorambucil

Answer: Chlorambucil
Not all chemotherapeutic drugs are equally emetogenic:
Most severe: cisplatin
Severe: Dacarbazine, Doxorubicin, Mechlorethamine, Daunorubicin
Relatively mild: Methotrexate, Fluorouracil (5-FU), and Chlorambucil

Q-12. Long term post antibiotic effect and time dependent killing seen in
a) Penicillin
b) Erythromycin
c) Clindamycin
d) Fluoroquinolones

Answer: Clindamycin
The three pharmaco-dynamic properties of antibiotics that best describe killing activity are time-dependence, concentration-dependence, and persistent effects.
Type I
Concentration-dependent killing and prolonged persistent effects: Aminoglycosides, Daptomycin, Fluoroquinolones, Ketolides
Type II
Time-dependent killing and Minimal persistent effects: Carbapenems, Cephalosporins, Erythromycin, Linezolid, Penicillins
Type III
Time-dependent killing and Moderate to prolonged persistent effects: Azithromycin, Clindamycin, Oxazolidinones, Tetracyclines, Vancomycin

Q-13. Which drug should be given to prevent side effect of Pemetrexed?
a) Folic Acid and B12
b) Folinic Acid and B12
c) Biotin and folate
d) Only folate

Answer: Folic Acid and B12
Pemetrexed is folate anti-metabolite. It works by inhibiting three enzymes used in purine and pyrimidine synthesis—thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase.
Folic acid and vitamin B12 should be given to prevent side effects.
Its indications are the treatment of pleural mesothelioma and non-small cell lung cancer.
The most common adverse reactions in patients receiving pemetrexed are hematologic toxicity, increase in hepatic enzymes, fatigue, gastrointestinal toxicity, sensory neuropathy, mucositis, and skin rash.

Q-14. Which of the following is NNRTI?
a) Nevirapine
b) Stavudine
c) Lamivudine
d) Raltegravir

Answer: Nevirapine
Medication for HIV/AIDS patients:
Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs):
Abacavir, Emtricitabine, Tenofovir, Lamivudine, Zidovudine
Non-nucleoside reverse transcriptase inhibitors (NNRTIs):
Efavirenz, Etravirine, Nevirapine, Delaviridine
Protease inhibitors (PIs):
Atazanavir, Indinavir, and ritonavir
Entry inhibitors:
Enfuvirtide and maraviroc
Integrase inhibitors:
Dolutegravir and raltegravir

Q-15. Drug matched correct mechanism of action
a) Timolol: Increases uveo-scleral flow
b) Pilocarpine: Increases trabecular out flow
c) Latanoprost: Decreases production of aqueous
d) Betaxolol: Increases trabecular out flow

Answer: Pilocarpine: Increases trabecular out flow
Pilocarpine: Increases trabecular out flow
Latanoprost: Increases uveo-scleral flow
Timolol, Betaxolol and Carbonic anhydrase inhibitors: Decreases production of aqueous