MDS PREP
A Class III antiarrhythmic agent that blocks K+ channels, prolongs action potential duration , and lengthens QT interval.
1) propranolol
2) acebutolol
3) sotalol
4) esmolol
Pharmacology Answer: 3
Sotalol is a Class III antiarrhythmic agent that blocks K+ channels, prolongs action potential duration (APD), and lengthens QT interval.
Noncardiac selective beta-adrenergic blocker.
The D-isomer has less than 1/50 beta-blocking activity of the L-isomer.
Sotalol possesses 30% of beta-blocking activity of propranolol
Clinically significant drug interaction occurs between pyridoxine and all the following drugs except?
1) Isoniazid
2) Cyclosporine
3) Levodopa
4) Hydralazine
Pharmacology Answer: 2
Pyridoxine – drug interactions :
INH – induces a pyridoxine deficiency state
Levodopa – pyridoxine promotes peripheral conversion of levodopa to dopamine – thus it decreases therapeutic action of levodopa in the brain
Oral contraceptive pills – decrease pyridoxine levels in some females
Hydralazine – impairment of pyridoxine utilisation
4-deoxy pyridoxine – pyridoxine antagonist
One of the side-effects of prilocaine is
1) Gastric bleeding
2) Porphyria
3) Photophobia
4) Methemoglobinemia
Pharmacology Answer: 4
Methemoglobinemia is a condition in which the iron within hemoglobin is oxidized from the ferrous (Fe2+) state to the ferric (Fe3+) state, resulting in the inability to transport oxygen and carbon dioxide. Clinically, this condition causes cyanosis, often posing a diagnostic dilemma
usually results from exposure to oxidizing substances (such as nitrates or nitrites, aniline dyes, or medications, including lidocaine, prilocaine, phenazopyridine hydrochloride (Pyridium], and others)
The Beta Blocker with local Anesthetic effect is
1) Pindolol
2) Atenolol
3) Esmorolol
4) Timolol
Pharmacology Answer: 1
Local anesthetic action, also known as "membrane-stabilizing" action, is a prominent effect of several -blockers Acebutolol, Labetalol, Pindolol Propranolol.
This action is the result of typical local anesthetic blockade of sodium channels and can be demonstrated experimentally in isolated neurons, heart muscle, and skeletal muscle membrane.
The neuromuscular blocker that does not need reversal of action by neostigmine at the end of the operation is :
1) d–Tubocurarine
2) Doxacurium
3) Pipecuronium
4) Mivacurium
Pharmacology Answer: 4
Long acting non-depolarizing (competitive) NM blocking agents require reversal with neostigmine.
Mivacurium is the shortest acting NDMR. It does not require reversal due to its short duration of action.
Mivacurium can be used in day care surgery.
Which of the following antihypertensive drugs should not be used in a patient on Lithium in order to prevent Lithium Toxicity?
1) Clonidine
2) Beta blockers
3) Calcium Channel Blockers
4) Diuretics
Pharmacology Answer: 4
Diuretics increase sodium loss in urine and increase lithium retention. Hence they should not be used in patients on Lithium.
Following drug interact with cefotaxime?
1) Digoxin
2) Paracetamol
3) Loop diuretics
4) Nifedipine
Pharmacology Answer: 3
Nephrotoxicity of cephalosporins is accentuated by concurrent administration of loop diuretics.
Morphine withdrawal is characterized by all except
1) Miosis
2) Yawning
3) Lacrimation
4) Diarrhea
Pharmacology Answer: 1
Withdrawal of morphine is associated with marked drug-seeking behavior.
Physical manifestations of abstinence are - lacrimation, sweating, yawning, anxiety, fear, restlessness, gooseflesh, mydriasis, tremor, insomnia, abdominal colic, diarrhea, dehydration, rise in BP, palpitation and rapid weight loss.
Delirium and convulsions are not a characteristic feature (contrast barbiturates) and are seen only occasionally.
Cardi-ovascular collapse and fatality are rare if supportive measures are instituted.