Question no 1 mbbs pharmacology as per standard

192339.jpg

Reading File

analyse_media

Finding Sources

Searching PubMed

"nocturnal enuresis"[MeSH Terms] AND desmopressin

Your photo shows only items i to viii of Q1 (10 × 2 marks). Items ix and x must be on page 2, so send that page and I'll do them too. I didn't have a pharmacology textbook in the library, so some answers rest on standard MBBS pharmacology (KDT/Tripathi) plus general medical texts.

Q	Answer	Reason
i	B	See below.
ii	B	Agranulocytosis is the major limitation of clozapine.
iii	B	WHO essential drugs satisfy the priority health care needs of the population.
iv	C	Loading dose = Vd × target plasma concentration (÷ F).
v	B	EDTA chelates lead ions and enhances renal excretion.
vi	C	Desmopressin is the preferred first-line drug.
vii	A	Carbamazepine is used in trigeminal neuralgia.
viii	D	Expected Hb rise is 0.5 to 1 g/dl per week.

i) Rectal route, the NOT-a-statement option is B.

The superior (internal) haemorrhoidal vein drains into the portal system, so drugs absorbed there undergo first-pass metabolism.
Drugs absorbed from the lower rectum through the middle and inferior veins bypass the liver, at least partly. So A and C are accepted statements.
Indomethacin and paracetamol suppositories are standard, so D is also a true statement.
Irritant drugs are unsuitable rectally because they cause proctitis. The route is useful for unpleasant-tasting drugs, which is likely why the option is worded this way.
This is the weakest item. Check B against your own class notes.

ii) Clozapine.

Agranulocytosis needs mandatory blood count monitoring. Kaplan & Sadock's Comprehensive Textbook of Psychiatry describes it as a potentially fatal black-box warning.
A is wrong because clozapine does help negative symptoms.
C and D are wrong because clozapine causes little hyperprolactinaemia and few extrapyramidal symptoms. It is the "atypical" prototype.

iii) Essential drugs.

The WHO definition is not "lifesaving drugs" or "emergency drugs".
Essential drugs should be available at all times, in adequate amounts, in suitable dosage forms and at an affordable price.

iv) Loading dose.

Loading dose = Vd × target concentration. Maintenance dose depends on clearance.
Barash's Clinical Anesthesia (Volume of Distribution) and Goldman-Cecil (Using a Loading Dose) both state that a larger Vd needs a larger loading dose to reach the same concentration.

v) EDTA in lead poisoning.

Calcium disodium EDTA exchanges calcium for lead, forming a stable, water-soluble complex that is excreted in urine.
A describes BAL (dimercaprol) and the other sulfhydryl-binding chelators, not EDTA.

vi) Nocturnal enuresis in a 7-year-old.

The first-line drug is desmopressin, a synthetic ADH (V2 agonist) analogue that reduces nocturnal urine volume. Non-drug measures such as an enuresis alarm are also first-line.
Imipramine is second-line. Oxybutynin is only added for an overactive bladder.
Furosemide has no role.
A 2025 Cochrane review on desmopressin exists (PMID 40728007). I did not read its abstract, so I'm not citing its findings.
Your handwritten mark on imipramine (A) looks incorrect.

vii) Carbamazepine.

It is the drug of choice for trigeminal neuralgia.
B is wrong because it is an enzyme inducer, including autoinduction.
C is wrong because its haematological toxicity is aplastic anaemia and agranulocytosis. Megaloblastic anaemia is the phenytoin association.
D is wrong because status epilepticus is treated with lorazepam or diazepam.

viii) Response to iron therapy.

Reticulocytosis appears in about 7 to 10 days. Hb should then rise by 0.5 to 1 g/dl per week.
This matches the Washington Manual (Oral Iron Preparations): reticulocytes rise within 1 week, and Hb rises about 2 g/dL every 3 weeks.

Your other handwritten marks (i B, ii B, iii B, iv C, v B, vii A, viii D) match these answers.

As per kdt statement irritant durgs can be given via rectal route

You're right. I was wrong to pick B. KDT lists irritant and unpleasant drugs as something that can be given rectally, as suppositories or retention enema. I don't have KDT in the library, so I'm going on your quote and my memory of that section. B is therefore a valid statement, and it can't be the "NOT a statement" option.

That leaves A, C and D. D (indomethacin and paracetamol suppositories) is plainly true.

Revised answer: A.

KDT's liver-bypass point is that drugs absorbed from the lower rectum enter the middle and inferior haemorrhoidal veins. These drain into the inferior vena cava, so the drugs avoid first-pass metabolism.
The superior (internal) haemorrhoidal vein drains into the portal vein. A drug absorbed there goes to the liver first.
"Drugs are absorbed in internal haemorrhoidal vein" therefore doesn't describe the bypass advantage, and it is the one that fits "NOT a statement".
C ("It bypasses liver") is the accepted KDT statement. It is only partial, since about 50% of the dose bypasses the liver, but it is what KDT lists as an advantage.

This is my best reading of the examiner's intent, not something I could confirm. The wording of A is loose, because the superior haemorrhoidal vein is one route of absorption. Your handwritten marks in the photo seem to cross out A and C, which doesn't settle it. If your KDT text or the university's answer key says otherwise, go with that.

The other answers (ii to viii) are unchanged.

This is a shared conversation. Sign in to Orris to start your own chat.