Q- Acute decrease in response to a drug after initial or repeated intake is known as which of the following drug interactions?
A- Additive
B- Permissive
C- Synergetic
D- Tachyphylactic
D- Tachyphylactic- Tachyphylaxis refers to an acute and rapid decrease in the response to a drug after initial or repeated doses. It is not additive, permissive, or synergistic.
Q- Which one of the following correctly describes nicotinic ACh receptors?
A- Enzyme-linked receptors
B- G-protein–coupled receptors
C- Ligand-gated Na+/K+ channels
C- Ligand-gated Na+/K+ channels- Nicotinic acetylcholine receptors are ligand-gated ion channels that open when acetylcholine binds, allowing Na⁺ to flow in and K⁺ to flow out, generating depolarization. They are not GPCRs or enzyme-linked receptors.
Q- Which of the following medications is the drug of choice for motion sickness?
A- Benztropine
B- Dicyclomine
C- Scopolamine
D- Tolterodine
C- Scopolamine- Scopolamine is the preferred medication for motion sickness because it effectively blocks muscarinic receptors in the vestibular system. The other drugs are anticholinergics but are used for different conditions.