Q1. Answer – 2. Dilatation of pupils. Acetylcholine causes pupillary constraiction by acting on M3 receptors.
Q2. Answer – 1. Scopolamine. It is an anticholinergic like atropine.
Q3. Answer – 4. Ipratropium. Why is it preferred over atropine for bronchial asthma?
Q4. Answer – 2. It crosses the blood brain barrier. Since it does not it is preferred for myasthenia gravis.
Q5. Answer – 1. Doxycycline. It is primarily excreted in faeces.
Q6. Answer – 4. Pseudomonas aeruginosa. Despite being broad spectrum antibiotics none of the tetracyclines are effective in pseudomonas infection.
Q7. Answer – 3. Streptococcal pneumonia. A beta-lactam antibiotic is the drug of choice in this condition.
Q8. Answer – 2. Amikacin. It is resistant to aminoglycoside inactivating enzymes.
Q9. Answer – 3. Streptomycin. Topical use is avoided because of high sensitization potential (allergic reactions).
Q10. Answer – 4. Postantibiotic effect. The other statements are wrong.
Aminoglycosides exhibit concentration dependent killing, are more active in alkaline pH and poorly absorbed orally.
Q12. Answer – 2. 2-3. INR = International normalized ratio.