Module 4 - PB

Proverbs 16:3

D) The new analgesic is less effective than the reference analgesic

A new analgesic exhibits only 30% of the response as compared from the reference analgesic. This implies that:
A. The new analgesic is more potent than the reference analgesic
B. The new analgesic is less potent than the reference analgesic
C. The new analgesic is more effective than the reference analgesic
D. The new analgesic is less effective than the reference analgesic

B) Drug Y is safer because its therapeutic index is higher

Drug X has an TD50 of 500mg/kg and an ED50 of 10 mg/kg. Drug Y has an TD50 of 200mg/kg and an ED50 of 2 mg/kg. Which statement is correct?
A. Drug X is safer because it has a higher therapeutic index
B. Drug Y is safer because its therapeutic index is higher
C. Drug X has a therapeutic index of 50, making it safer than Drug Y
D. Drug Y is safer because it has a lower TD50

B) Parallel rightward shift with unchanged Emax

Adding a competitive antagonist to a system already exposed to an agonist produces which change on the dose-response curve?
A. Downward shift with decreased Emax, no change in ED50
B. Parallel rightward shift with unchanged Emax
C. Leftward shift with increased potency
D. Flattening of the curve with loss of sigmoid shape

A) Amiodarone

Which of the following agents targets blocks a voltage-gated ion channel?
A. Amiodarone
B. Aspirin
C. Propranolol
D. Digoxin

B) Lower intrinsic activity even at full receptor occupancy, and can antagonize morphine's effect when co-administered

Buprenorphine is characterized by which pharmacodynamic property?
A. Higher efficacy but lower potency than morphine
B. Lower intrinsic activity even at full receptor occupancy, and can antagonize morphine's effect when co-administered
C. Equal Emax to morphine with a rightward-shifted curve
D. Zero intrinsic activity at the receptor

C) 10 mg/L

A drug is eliminated primarily by first-order kinetics. If the plasma concentration is 80 mg/L at time zero and the half-life is 4 hours, the concentration at 12 hours will be approximately:
A. 40 mg/L
B. 20 mg/L
C. 10 mg/L
D. 5 mg/L

C) Large particle size

Which property of a drug DOES NOT permit passive into membranes?
A. Lipophilic
B. High partition coefficient
C. Large particle size
D. High diffusion coefficient

A) 500mg

A 500-mg drug has an oral bioavailability of 25% due to extensive hepatic first-pass metabolism. If it was administered intravenously, how much was absorbed?
A. 500mg
B. 375mg
C. 125mg
D. 25mg

B) Absorption, Distribution, Metabolism, Excretion

What are the four main processes of pharmacokinetics?
A. Binding, Transport, Storage, Excretion
B. Absorption, Distribution, Metabolism, Excretion
C. Ionization, Diffusion, Filtration, Secretion
D. Induction, Inhibition, Conjugation, Elimination

B) Liver

Which organ is the primary site of drug metabolism in the body?
A. Kidney
B. Liver
C. Lungs
D. Spleen

D) Bioavailability

What term describes the fraction of an administered drug dose that reaches the systemic circulation unchanged?
A. Clearance
B. Volume of distribution
C. Half-life
D. Bioavailability

A) The time required for the plasma concentration of a drug to be reduced by 50%

What is the definition of drug half-life (t½)?
A. The time required for the plasma concentration of a drug to be reduced by 50%
B. The time required for the drug to reach peak plasma concentration
C. The time required for a drug to be fully absorbed
D. The time required for a drug to bind completely to plasma proteins

B) Decreased contraceptive plasma levels and risk of contraceptive failure

Rifampin is a potent inducer of hepatic CYP3A4. Co-administration with an oral contraceptive will most likely result in:
A. Increased contraceptive plasma levels and toxicity
B. Decreased contraceptive plasma levels and risk of contraceptive failure
C. No interaction because oral contraceptives are renally eliminated
D. Increased half-life of the contraceptive

C) It increases the ionized fraction of the weak acid in urine

A weak acid drug is administered. In cases of overdose, alkalinizing the urine enhances elimination primarily because:
A. It increases glomerular filtration rate
B. It decreases renal blood flow
C. It increases the ionized fraction of the weak acid in urine
D. It converts the drug to its lipid-soluble form, enhancing passive reabsorption

A) A transient increase in free (active) drug concentration

A drug that is highly protein-bound is displaced by a second highly protein-bound drug. The most likely immediate clinical consequence is:
A. A transient increase in free (active) drug concentration
B. No clinically significant change since total drug concentration is unchanged
C. Permanent increase in total drug concentration
D. Decreased drug efficacy

C) Beta-2 adrenergic

Which receptor subtype, when stimulated, mediates smooth muscle relaxation via increased cAMP in bronchial tissue?
A. M3 muscarinic
B. Alpha-1 adrenergic
C. Beta-2 adrenergic
D. Beta-1 adrenergic

B) Irreversible inhibition of acetylcholinesterase

A patient with organophosphate poisoning presents with salivation, lacrimation, urination, defecation, GI distress, and emesis, along with bradycardia and miosis. The mechanism is:
A. Direct muscarinic receptor agonism
B. Irreversible inhibition of acetylcholinesterase
C. Blockade of nicotinic receptors at the neuromuscular junction
D. Competitive antagonism of adrenergic receptors

D) Nicotinic antagonist

What is the mechanism of action of Hexamethonium?
A. Muscarinic agonist
B. Muscarinic antagonist
C. Nicotinic agonist
D. Nicotinic antagonist

C) Skeletal muscle weakness

Atropine is used to counter the muscarinic effects of organophosphate toxicity, but it does NOT reverse:
A. Bradycardia
B. Bronchorrhea/secretions
C. Skeletal muscle weakness
D. Miosis

B) Contracts the ciliary muscle, opening the trabecular meshwork and increasing aqueous outflow

Pilocarpine, a muscarinic agonist, is used in the treatment of open-angle glaucoma primarily because it:
A. Decreases aqueous humor production via ciliary body beta-blockade
B. Contracts the ciliary muscle, opening the trabecular meshwork and increasing aqueous outflow
C. Causes mydriasis, widening the anterior chamber angle
D. Inhibits carbonic anhydrase in the ciliary epithelium

C) III, IV, V

Anticholinergic effects:
I. Salivation
II. Diarrhea
III. Mydriasis
IV. Erythema
V. Tachycardia
A. I, II, III, IV, V
B. II, III, IV, V
C. III, IV, V
D. III, IV only

B) Phenoxybenzamine

Which drug is a nonselective, irreversible alpha-adrenergic antagonist used preoperatively in pheochromocytoma to prevent hypertensive crisis?
A. Prazosin
B. Phenoxybenzamine
C. Tamsulosin
D. Propranolol

A) Phenylephrine

The following are used as antiasthma agents, except:
A. Phenylephrine
B. Epinephrine
C. Isoproterenol
D. Salmeterol

D) Improves urine flow

Tamsulosin is used in benign prostatic hyperplasia because it:
A. Shrinks the prostate gland
B. Blocks 5-alpha reductase
C. Stimulates detrusor muscle contraction
D. Improves urine flow

C) Clonidine

Which antihypertensive agent decreases sympathetic outflow from the CNS?
A. Prazosin
B. Atenolol
C. Clonidine
D. Losartan

C) Phenylephrine – urinary incontinence

Which pairing as to toxicity is mismatched?
A. Methylodopa – (+) Coomb's Test
B. Salbutamol – ventricular tachycardia
C. Phenylephrine – urinary incontinence
D. Atenolol – bradycardia

B) Alpha-1, beta-1, and beta-2 agonist, which addresses all major components of anaphylaxis

Epinephrine for anaphylaxis:
A. Beta-2 agonists, relieving bronchospasm
B. Alpha-1, beta-1, and beta-2 agonist, which addresses all major components of anaphylaxis
C. Anticholinergic, which prevents excessive salivation
D. Alpha-1 antagonist, thereby relieving excessive vasoconstriction

A) Terbutaline

Which is not used for rhinitis?
A. Terbutaline
B. Phenylpropanolamine
C. Pseudoephedrine
D. Phenylephrine

E) I, II, III only

The following are vasoconstrictors:
I. Vasopressin
II. Dobutamine
III. Norepinephrine
IV. Dopamine
V. Phentolamine
A. I, II, III, IV, V
B. II, III, IV
C. I, II, III, IV
D. I, II, III, IV
E. I, II, III only

B) Inhibiting the release of acetylcholine from presynaptic vesicles

Botulinum toxin produces skeletal muscle paralysis by:
A. Blocking postsynaptic nicotinic receptors
B. Inhibiting the release of acetylcholine from presynaptic vesicles
C. Depolarizing the motor end plate persistently
D. Inhibiting acetylcholineesterase

C) Succinylcholine

Suxamethonium is:
A. Sugammadex
B. Succinyl CoA
C. Succinylcholine
D. Dimercaptosuccinic acid

C) An antimuscarinic

What is the meaning of an anticholinergic?
A. An antinocitinic
B. An anticholinesterase
C. An antimuscarinic
D. An antigangliocin

B) Selective alpha-1 agonism causing vasoconstriction

Phenylephrine is commonly used as a nasal decongestant and to treat hypotension during spinal anesthesia. Its mechanism is:
A. Selective beta-1 agonism increasing cardiac output
B. Selective alpha-1 agonism causing vasoconstriction
C. Nonselective beta agonism
D. Alpha-2 agonism reducing central sympathetic outflow

D) Alzheimer's Disease

Rivastigmine is clinically used in:
A. Myasthenia gravis
B. Parkinsonism
C. Extrapyramidal syndrome
D. Alzheimer's Disease

C) Carvedilol

Which is a mixed alpha and beta blocker?
A. Propranolol
B. Nebivolol
C. Carvedilol
D. Atenolol

B) Decreasing angiotensin II while increasing bradykinin

Enalapril reduces blood pressure by which combination of mechanisms?
A. Increasing angiotensin II and decreasing bradykinin
B. Decreasing angiotensin II while increasing bradykinin
C. Blocking the AT1 receptor directly
D. Increasing renin release only

C) Class III

Which class of antiarrhythmic drugs primarily prolongs the action potential duration and effective refractory period by blocking potassium channels?
A. Class IA
B. Class II
C. Class III
D. Class IV

A) Losartan

Antianginal drugs, except:
A. Losartan
B. ISDN
C. Verapamil
D. Metoprolol

B) Thyroid dysfunction

A major concern with long-term amiodarone therapy is:
A. Hyperkalemia
B. Thyroid dysfunction
C. Acute bronchospasm
D. Nephrotoxicity

B) Have significant negative chronotropic and dromotropic effects

Verapamil and diltiazem are preferred over amlodipine for rate control in atrial fibrillation because they:
A. Act predominantly on vascular smooth muscle with minimal cardiac effect
B. Have significant negative chronotropic and dromotropic effects
C. Cause reflex tachycardia, useful for rate control
D. Selectively block T-type calcium channels only

D) HCTZ – Hypercalcemia

Which is correctly matched as to drug and toxicity?
A. Low dose ISDN – reflex tachycardia
B. Losartan – dry cough
C. Spironolactone – hypokalemia
D. HCTZ – Hypercalcemia

B) Life-threatening hypotension

Sildenafil plus ISDN:
A. Severe hypertension
B. Life-threatening hypotension
C. Reflex bradycardia
D. Acute renal failure

A) Digoxin

"More calcium is available in the sarcoplasmic reticulum for the next contraction, increasing contractility."
A. Digoxin
B. Inamrinone
C. Dobutamine
D. Bosentan

C) Inotropic

Inamrinone:
A. Antianginal
B. Cardiotoxic
C. Inotropic
D. Diuretic

A) HCTZ

Which diuretic is useful in osteoporosis and may cause hypercalcemia?
A. HCTZ
B. Furosemide
C. Spironolactone
D. Acetazolamide

B) Antithrombin III

Unfractionated heparin's anticoagulant effect requires binding to:
A. Vitamin K
B. Antithrombin III
C. Plasminogen
D. Fibrinogen

A) Generally does not require aPTT monitoring

Enoxaparin differs from unfractionated heparin in that it:
A. Generally does not require aPTT monitoring
B. Requires antithrombin III-independent action
C. Has a shorter half-life requiring more frequent dosing
D. Is fully reversed by protamine sulfate

D) Alteplase

Which is a plasminogen activator?
A. Warfarin
B. Tranexamic acid
C. Apixaban
D. Alteplase

B) Irreversible blockade of the P2Y12 ADP receptor on platelets

Clopidogrel's antiplatelet mechanism is:
A. Irreversible inhibition of cyclooxygenase-1
B. Irreversible blockade of the P2Y12 ADP receptor on platelets
C. Direct GPIIb/IIIa receptor antagonist
D. Inhibition of thromboxane synthase

D) Apixaban – thrombolytic

Which is incorrectly paired?
A. Aspirin – antiplatelet
B. Warfarin – anticoagulant
C. Tranexamic acid – antifibrinolytic
D. Apixaban – thrombolytic

D) Binding bile acids in the intestine

Cholestyramine lowers LDL cholesterol primarily by:
A. Inhibiting intestinal cholesterol absorption
B. Inhibiting HMG-CoA reductase
C. Activating lipoprotein lipase
D. Binding bile acids in the intestine

B) Rhabdomyolysis

A patient on a statin presents with severe muscle pain and dark urine; labs show markedly elevated CK and myoglobinuria. This is:
A. A benign, expected side effect requiring no action
B. Rhabdomyolysis
C. A sign of statin-induced hepatotoxicity only
D. An allergic reaction unrelated to the statin

B) Triglycerides

Fenofibrate (a fibrate) is most effective for lowering which lipid parameter?
A. LDL cholesterol
B. Triglycerides
C. Lp(a)
D. Total cholesterol only

B) Selectively inhibiting intestinal absorption

Ezetimibe lowers LDL cholesterol by:
A. Inhibiting HMG-CoA reductase
B. Selectively inhibiting intestinal absorption
C. Binding bile acids in the gut lumen
D. Activating PCSK9

A) Fenofibrate

Which of the following is a PPAR-alpha agonist?
A. Fenofibrate
B. Atorvastatin
C. Ezetimibe
D. Nicotinic acid

B) Cross the blood-brain barrier and block central H1 receptors

First-generation antihistamines cause sedation primarily because they:
A. Are H2 receptor selective
B. Cross the blood-brain barrier and block central H1 receptors
C. Stimulate central dopamine receptors
D. Block muscarinic receptors peripherally only

B) Chemotherapy-induced nausea and vomiting

Serotonin (5-HT3) receptor antagonists such as ondansetron are used primarily to treat:
A. Migraine headache
B. Chemotherapy-induced nausea and vomiting
C. Depression
D. Hypertension

D) Betahistine

The following are antihistamines, except:
A. Cimetidine
B. Hydroxyzine
C. Cetirizine
D. Betahistine

A) NSAID-induced ulcer

Misoprostol's use:
A. NSAID-induced ulcer
B. Erectile dysfunction
C. Glaucoma
D. Primary pulmonary hypertension

A) Insulin

Autacoids, except:
A. Insulin
B. Bradykinin
C. Eicosanoids
D. Histamine

D) Dapagliflozin

Increasing renal glucose excretion via SGLT2 inhibition is a mechanism of:
A. Gliclazide
B. Metformin
C. Acarbose
D. Dapagliflozin

A) Glipizide

Which of the following causes hypoglycemia and weight gain?
A. Glipizide
B. Metformin
C. Semaglutide
D. Sitagliptin

A) Tirzepatide

Mounjaro:
A. Tirzepatide
B. Semaglutide
C. Exenatide
D. Liraglutide

C) Heart Failure

Aside from being an antidiabetic, Empagliflozin is also used in which cardiovascular disease?
A. Hypertension
B. Angina Pectoris
C. Heart Failure
D. Arrhythmia

B) Mealtime coverage

Regular insulin has an onset and duration profile suited for:
A. Basal, once-daily coverage
B. Mealtime coverage
C. Ultra-long basal coverage lasting 24+ hours with no peak
D. Emergency reversal of hypoglycemia

A) Levothyroxine

Which is NOT an antihyroid agent?
A. Levothyroxine
B. Methimazole
C. PTU
D. SSKI

D) PTU and Methimazole

Drugs inhibit thyroid peroxidase, reducing new hormone synthesis:
A. SSKI and PTU
B. Methimazole and Thiocyanate
C. Propranolol and PTU
D. PTU and Methimazole

A) Abrupt discontinuation can precipitate acute adrenal insufficiency

Why tapering using prednisone is required?
A. Abrupt discontinuation can precipitate acute adrenal insufficiency
B. Abrupt discontinuation can precipitate acute adrenal excess
C. Abrupt discontinuation can precipitate acute thyroid excess
D. Abrupt discontinuation can precipitate acute thyroid insufficiency

B) Negative feedback on GnRH/LH/FSH

Combined oral contraceptives (estrogen + progestin) prevent pregnancy primarily by:
A. Inducing endometrial hyperplasia
B. Negative feedback on GnRH/LH/FSH
C. Directly destroying ova
D. Blocking fertilization

D) Tolvaptan

Which medication is indicated for vasopressin excess?
A. Octreotide
B. Mecasermin
C. Desmopressin
D. Tolvaptan

D) Antiinflammatory

The following are clinical uses of narcotics, except:
A. Antitussives
B. Analgesics
C. Anesthetics
D. Antiinflammatory
E. None of the above

A) Naloxone

This agent competitively displaces opioid agonists from mu (and other) receptors without activating them, rapidly reversing life-threatening respiratory depression:
A. Naloxone
B. Methadone
C. Thebaine
D. Codeine

E) More than one

Which effect is seen in aspirin, but not in paracetamol?
A. Analgesic
B. Antipyretic
C. Antiinflammatory
D. Antiplatelet
E. More than one

A) Celecoxib

Classic GI toxicities is seen with the following NSAIDs, except:
A. Celecoxib
B. Aspirin
C. Piroxicam
D. Ibuprofen

C) Aspirin

Reye's syndrome if associated with which NSAID?
A. Ibuprofen
B. Indomethacin
C. Aspirin
D. Diclofenac

B) NAC

Antidote for acetaminophen poisoning:
A. Flumazenil
B. NAC
C. Atropine
D. Diazepam

C) Intrasynovial

Methylprednisolone depot is usually administered:
A. Oral
B. Intravenous
C. Intrasynovial
D. Topical

D) May cause hypnosis at relatively low doses

Which of the following is FALSE about benzodiazepines?
A. They increase the frequency of Cl-channel opening
B. Have a wider margin of safety compared to barbiturates
C. Include chlordiazepoxide and chlorazepate
D. May cause hypnosis at relatively low doses

A) LSD

Which of the following is a CNS stimulant?
A. LSD
B. Lithium
C. Phenobarbital
D. Carbamazepine

C) Blocking T-type calcium channels in thalamic neurons

Ethosuximide's primary anticonvulsant mechanism is:
A. Enhancing GABA-A receptor chloride conductance
B. Use-dependent blockade of voltage-gated sodium channels
C. Blocking T-type calcium channels in thalamic neurons
D. Inhibiting glutamate synthesis

B) I, II

What are the reasons for combining Levodopa with Carbidopa?
I. Enhanced efficacy of levodopa
II. Enhanced peripheral effects of levodopa
III. Anticholinergic effects
A. I, II, III
B. I, II
C. I only
D. II only

B) Sertraline and Escitalopram

Which are SSRIs?
A. Imipramine and Amitriptyline
B. Sertraline and Escitalopram
C. Milnacipran and Venlafaxine
D. Moclobemide and Tranylcypromine

B) Serotonin syndrome

Combining an SSRI with an MAO inhibitor poses a significant risk of:
A. Hypertensive crisis
B. Serotonin syndrome
C. Malignant hyperthermia
D. Agranulocytosis

C) Antiparkinsonian

Which of the following does not describe Haloperidol?
A. Antipsychotic
B. Antimanic
C. Antiparkinsonian
D. Neuroleptic

A) Salmeterol

SABA, except:
A. Salmeterol
B. Salbutamol
C. Albuterol
D. Terbutaline

D) Montelukast

This agent is especially helpful in exercise-induced and aspirin-exacerbated respiratory disease:
A. Salbutamol
B. NSAIDs
C. Levocetirizine
D. Montelukast

B) Blocking M3 muscarinic receptors on bronchial smooth muscle

Ipratropium, an inhaled anticholinergic, provides bronchodilation in COPD by:
A. Stimulating beta-2 receptors
B. Blocking M3 muscarinic receptors on bronchial smooth muscle
C. Inhibiting phosphodiesterase
D. Blocking histamine receptors

B) Phosphodiesterase inhibition

Theophylline's mechanism of bronchodilation is thought to involve:
A. Selective beta-2 agonism
B. Phosphodiesterase inhibition
C. Direct inhibition of acetylcholinesterase
D. Leukotriene receptor blockade

D) Oxymetazoline

Which is not useful as an antitussive?
A. Diphenhydramine
B. Dextromethorphan
C. Butamirate citrate
D. Oxymetazoline

D) Neutralization

What is the mechanism of action of magnesium hydroxide for hyperacidity?
A. Proton pump inhibition
B. H2 blockade
C. Prostaglandin-mediated cytoprotection
D. Neutralization

D) Causes gynecomastia

Incorrect about ranitidine:
A. Competitively antagonizes the H2 receptor on parietal cells
B. Less potent than PPIs
C. Less interactant than cimetidine
D. Causes gynecomastia

B) Minimized abuse potential at normal doses

TRUE about loperamide:
A. Laxative agent
B. Minimized abuse potential at normal doses
C. Acts on central mu receptors in the brain
D. Increases motility in the GUT

B) Forming covalent cross-links with DNA

Alkylating agents exert cytotoxic effects on cancer cells by:
A. Inhibiting microtubule polymerization
B. Forming covalent cross-links with DNA
C. Inhibiting topoisomerase II exclusively
D. Blocking folate metabolism

C) Methotrexate

Leucovorin rescue is employed with the use of:
A. Cisplatin
B. Cyclophosphamide
C. Methotrexate
D. Doxorubicin

C) Anastrazole

Which is an aromatase inhibitor used in the treatment of breast cancer?
A. Tamoxifen
B. Raloxifene
C. Anastrazole
D. Goserelin

B) Replenishes hepatic glutathione stores

N-acetylcysteine is the antidote for acetaminophen overdose because it:
A. Directly binds and inactivates NAPQI in the bloodstream
B. Replenishes hepatic glutathione stores
C. Induces vomiting to remove unabsorbed drug
D. Chelates the toxic metabolite in the kidney

B) Iron overdose

Deferoxamine is the chelating agent of choice for which acute toxic ingestion?
A. Lead poisoning
B. Iron overdose
C. Mercury poisoning
D. Copper toxicity

A) Competitively inhibits alcohol dehydrogenase

Fomepizole is used in methanol and ethylene glycol poisoning because it:
A. Competitively inhibits alcohol dehydrogenase
B. Directly neutralizes formic acid and oxalic acid
C. Enhances renal excretion of the parent alcohol
D. Stimulates hepatic metabolism to clear the toxin faster

D) Permethrin - inhibits superoxide dismutase

Which of the following is incorrect regarding mechanism by certain poisons?
A. Hydrogen sulfide - inhibits cytochrome oxidase
B. Malathion - anticholinesterase
C. Aspirin - cyclooxygenase
D. Permethrin - inhibits superoxide dismutase

A) Vitamin K1

Drug for warfarin poisoning is:
A. Vitamin K1
B. Vitamin K2
C. Vitamin K3
D. Vitamin K4