WorksheetsPharmacology Quiz
Total questions: 10
Worksheet time: 5mins
A drug has a volume of distribution (V_d) of 500 Liters in a 70kg man. This indicates that the drug is:
Confined to the plasma compartment
Highly bound to plasma albumin
Extensively sequestered in peripheral tissues (e.g., fat or muscle)
Excreted rapidly by the kidneys
According to the Henderson-Hasselbalch principle, a weak acid drug (pKa = 3.5) will be most rapidly absorbed from the stomach (pH 1.5) because:
It is predominantly in the ionized, water-soluble form
It is predominantly in the non-ionized, lipid-soluble form
The pH gradient favors active transport
Weak acids are always absorbed faster than weak bases
Which of the following best describes a "Partial Agonist" in the presence of a full agonist?
It increases the V_{max} of the full agonist
It acts as a competitive antagonist, reducing the overall maximal response
It shifts the dose-response curve of the full agonist to the left
It binds irreversibly to the receptor site
The "Therapeutic Index" of a drug is a measure of its safety and is calculated as the ratio of:
ED_{50} to LD_{50}
LD_{50} to ED_{50}
Clearance to Half-life
Bioavailability to V_d
In "First-Order Kinetics" of elimination:
A constant amount of drug is eliminated per unit time
The elimination rate is independent of plasma concentration
A constant fraction of the drug is eliminated per unit time
The half-life increases as the plasma concentration increases
Which of the following physiological effects is mediated by the stimulation of M_3 Muscarinic receptors?
Tachycardia
Mydriasis (Pupillary dilation)
Bronchoconstriction and increased glandular secretion
Decreased gastrointestinal motility
"Physostigmine" is clinically distinct from "Neostigmine" primarily because Physostigmine:
Is a reversible cholinesterase inhibitor
Is a quaternary ammonium compound that does not cross the Blood-Brain Barrier
Is a tertiary amine that can cross the Blood-Brain Barrier to treat Atropine toxicity
Has direct nicotinic agonist activity at the NMJ
A patient is given an intravenous bolus of Epinephrine. Pre-treatment with which of the following drugs would cause "Epinephrine Reversal" (a decrease in blood pressure instead of an increase)?
Propranolol (Beta-blocker)
Phentolamine (Alpha-blocker)
Atropine (Muscarinic blocker)
Phenylephrine (Alpha-agonist)
Which of the following is the "Rate-Limiting Step" in the biosynthesis of Catecholamines (Norepinephrine and Epinephrine)?
Conversion of DOPA to Dopamine by Dopa-decarboxylase
Hydroxylation of Tyrosine to DOPA by Tyrosine Hydroxylase
Transport of Norepinephrine into storage vesicles
Hydroxylation of Dopamine by Dopamine beta-hydroxylase
"Pilocarpine" is primarily used in the treatment of Glaucoma because it:
Causes paralysis of the ciliary muscle
Produces mydriasis, opening the canal of Schlemm
Produces miosis and contraction of the ciliary muscle, increasing aqueous outflow
Inhibits the production of aqueous humor at the ciliary body
