This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anaesthesia, Subject name: Pharmacology
Which of the following is used as a preanaesthetic medication? 
Select and explain. 
A. Propanthelene, B. Glycopyrrolate, C. Ipratropium bromide, D. Hyoscine
B: Glycopyrrolate
Answer: B: Glycopyrrolate 
Explanation: Ans. is 'b > d' i.e., Glycopyrrolate > Hyoscine Drugs used in premedication1.Sedative - antianxiety-Diazepam/Lorazepam/Midazolam.-Lorazepam is used most commonly-Midazolam is used for day care surgery2.Opioids-Morphine/Pethidine3.Anticholinergics-Atropine/ Hyoscine/ Glycopyrrolate.4.Neuroleptics-Haloperidol/chlorapromazine/triflupromazine5.H2 blocker or proton pump inhibitor-Ranitidine/Famotidine, omeprazole/Pantoprazole.6.Antiemitics-Metoclopramide/ Domperidone/ Ondansetron/ Hyoscine/ Ondansetron* To control secretion, anticholinergics (Glycopyrrolate, atropine or scopolamine) are used. Gycopyrrolate is a preferred anticholinergic over atropine and scopolamine (hyoscine) because it does not crosses blood brain barrier and devoid of central side effects.Note: Atropine is a natural alkaloid, used in OPC poisoning and has profound central CNS effects.