Pharmacology MCQs (Part-2)

This pharmacology quiz test will help you to prepare for NAPLEX.

1 / 25

Which of the following is a systemic effect of a muscarinic agonist?

Reduced heart rate (bradycardia).

Increased blood pressure.

Mydriasis (dilation of the pupil).

Reduced urinary frequency.

2 / 25

A dentist would like to reduce salivation in a patient in preparation for an oral surgical procedure. Which of the following strategies will be useful in reducing salivation?

Activate nicotinic receptors in the salivary glands.

Block nicotinic receptors in the salivary glands.

Activate muscarinic receptors in the salivary glands.

Block muscarinic receptors in the salivary glands.

3 / 25

Botulinum toxin blocks the release of acetylcholine from cholinergic nerve terminals. Which of the following is a possible effect of botulinum toxin?

Skeletal muscle paralysis.

Improvement of myasthenia gravis symptoms.

Increased salivation.

Reduced heart rate.

4 / 25

Which of the following is correct regarding membrane receptors and signal transduction?

ANS neurotransmitters bind to membrane receptors on the effector cells, which leads to intracellular events.

Cholinergic muscarinic receptors are examples of ionotropic receptors.

Cholinergic nicotinic receptors are examples of metabotropic receptors.

Metabotropic receptors activate ion channels directly.

5 / 25

All of the following statements regarding central control of autonomic functions are correct except:

Baroreceptors are pressure sensors located at various cardiovascular sites.

The parasympathetic system is activated by the CNS in response to a sudden drop in blood pressure.

The parasympathetic system is activated by the CNS in response to a sudden increase in blood pressure.

The sympathetic system is activated by the CNS in response to a sudden drop in blood pressure.

6 / 25

Which of the following is correct regarding neurotransmitters and neurotransmission?

Neurotransmitters are released from the presynaptic nerve terminals.

Neurotransmitter release is triggered by the arrival of action potentials in the postsynaptic cell.

Intracellular calcium levels drop in the neuron before the neurotransmitter is released.

Serotonin and dopamine are the primary neurotransmitters in the ANS.

7 / 25

Which of the following statements concerning the parasympathetic nervous system is correct?

The parasympathetic system uses norepinephrine as a neurotransmitter.

The parasympathetic system often discharges as a single, functional system.

The parasympathetic division is involved in accommodation of near vision, movement of food, and urination.

The postganglionic fibers of the parasympathetic division are long compared to those of the sympathetic nervous system.

8 / 25

Which of the following statements is correct regarding the sympathetic and parasympathetic systems?

Acetylcholine activates muscarinic receptors.

Acetylcholine activates adrenergic receptors.

Norepinephrine activates muscarinic receptors.

Activation of the sympathetic system causes a drop in blood pressure.

9 / 25

Which of the following changes could theoretically happen in a person when the parasympathetic system is inhibited using a pharmacological agent?

Reduction in heart rate.

Constriction of the pupil (miosis).

Increase in gastric motility.

Dry mouth (xerostomia).

10 / 25

Which of the following physiological changes could happen when a person is attacked by a grizzly bear?

Increase in heart rate.

Increase in lacrimation (tears).

Constriction of the pupil (miosis).

Increase in gastric motility.

11 / 25

Which of the following is correct regarding somatic motor neurons?

The neurotransmitter at the somatic motor neuron ganglion is acetylcholine.

The neurotransmitter at the somatic motor neuron ganglion is norepinephrine.

Somatic motor neurons innervate smooth muscles.

Somatic motor neurons do not have ganglia.

12 / 25

Which of the following is correct regarding the autonomic nervous system (ANS)?

Afferent neurons carry signals from the CNS to the effector organs.

The neurotransmitter at the parasympathetic ganglion is norepinephrine (NE).

The neurotransmitter at the sympathetic ganglion is acetylcholine (ACh).

Sympathetic neurons release ACh in the effector organs.

13 / 25

Which of the following would up-regulate postsynaptic β1 adrenergic receptors?

Daily use of amphetamine that causes norepinephrine to be released.

A disease that causes an increase in the activity of norepinephrine neurons.

Daily use of isoproterenol, a β1 receptor agonist.

Daily use of propranolol, a β1 receptor antagonist.

14 / 25

Which of the following statements most accurately describes a system having spare receptors?

The number of spare receptors determines the maximum effect.

Spare receptors are sequestered in the cytosol.

A single drug–receptor interaction results in many cellular response elements being activated.

Spare receptors are active even in the absence of an agonist.

15 / 25

In the presence of picrotoxin, diazepam is less efficacious at causing sedation, regardless of the dose. Picrotoxin by itself has no sedative effect even at the highest dose. Which of the following is correct?

Picrotoxin is a competitive antagonist.

Diazepam is a full agonist, and picrotoxin is a partial agonist.

Diazepam is less efficacious than is picrotoxin.

Picrotoxin is a noncompetitive antagonist.

16 / 25

In the presence of pentazocine, a higher concentration of morphine is required to elicit full pain relief. Pentazocine by itself has a smaller analgesic effect than does morphine, even at the highest dose. Which of the following is correct regarding these medications?

Pentazocine is a competitive antagonist.

Morphine is a full agonist, and pentazocine is a partial agonist.

Morphine is less efficacious than is pentazocine.

Morphine is less potent than is pentazocine.

17 / 25

If 10 mg of naproxen produces the same analgesic response as 100 mg of ibuprofen, which of the following statements is correct?

Naproxen is more efficacious than is ibuprofen.

Naproxen is more potent than ibuprofen.

Naproxen is a full agonist, and ibuprofen is a partial agonist.

Naproxen is a competitive antagonist.

18 / 25

Isoproterenol produces maximal contraction of cardiac muscle in a manner similar to epinephrine. Which of the following best describes isoproterenol?

Full agonist

Partial agonist

Competitive antagonist

Irreversible antagonist

19 / 25

A drug with a half-life of 10 hours is administered by continuous intravenous infusion. Which of the following best approximates the time for the drug to reach steady state?

10 hours

20 hours

30 hours

40 hours

20 / 25

Alkalization of urine by giving bicarbonate is used to treat patients presenting with phenobarbital (weak acid) overdose. Which of the following best describes the rationale for alkalization of urine in this setting?

To reduce tubular reabsorption of phenobarbital.

To decrease ionization of phenobarbital.

To increase glomerular filtration of phenobarbital.

To decrease proximal tubular secretion.

21 / 25

Which of the following phase II metabolic reactions makes phase I metabolites readily excretable in urine?

Oxidation

Reduction

Glucuronidation

Hydrolysis

22 / 25

Which of the following is true about the blood–brain barrier?

Endothelial cells of the blood–brain barrier have slit junctions.

Ionized or polar drugs can cross the blood–brain barrier easily.

Drugs cannot cross the blood–brain barrier through specific transporters.

Lipid-soluble drugs readily cross the blood–brain barrier.

23 / 25

Which of the following types of drugs will have maximum oral bioavailability?

Drugs with high first-pass metabolism.

Highly hydrophilic drugs.

Largely hydrophobic, yet soluble in aqueous solutions.

Chemically unstable drugs.

24 / 25

An 18-year-old female patient is brought to the emergency department due to drug overdose. Which of the following routes of administration is the most desirable for administering the antidote for the drug overdose?

Oral

Subcutaneous

Intramuscular

Intravenous

25 / 25

Chlorothiazide is a weakly acidic drug with a pKa of 6.5. If administered orally, at which of the following sites of absorption will the drug be able to readily pass through the membrane?

Mouth (pH approximately 7.0)

Stomach (pH of 2.5)

Duodenum (pH approximately 6.1)

Jejunum (pH approximately 8.0)

Your score is

The average score is 0%

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Pharmacology MCQs (Part-2)

NAPLEX Calculation Practice (Part-1)

NAPLEX Calculation Practice (Part-2)

Pharmacology MCQs (Part-1)

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