Why does Phenytoin exhibit non-linear (Michaelis-Menten / capacity-limited) pharmacokinetics at therapeutic concentrations, and what is the clinical consequence?

Hepatic CYP2C9/2C19 metabolizing enzymes become saturated within the therapeutic range (10–20 mg/L or 40–80 µmol/L), switching kinetics from first-order to zero-order; small increases in daily dose produce disproportionately large, toxic increases in steady-state serum concentration.

In PEBC Cardiology, which Statins are classified as High-Intensity (lowering LDL-C by ≥50%), and what are their key drug interactions?

Rosuvastatin 20–40 mg daily and Atorvastatin 40–80 mg daily. Atorvastatin, Simvastatin, and Lovastatin are metabolized by CYP3A4 (avoid grapefruit juice, macrolides, azoles, protease inhibitors); Rosuvastatin and Pravastatin are minimally metabolized by CYP3A4 (safer with CYP3A4 inhibitors). Never combine Gemfibrozil with any statin due to rhabdomyolysis risk (OATP1B1 inhibition).

Under the National Association of Pharmacy Regulatory Authorities (NAPRA) National Drug Schedules (NDS) in Canada, define Schedule I, Schedule II, Schedule III, and Unscheduled drugs.

Schedule I: Requires a prescription for sale (dispensed by a pharmacist). Schedule II: Non-prescription ('Behind-the-Counter'—no public self-selection; requires pharmacist intervention/assessment at the counter, e.g., insulin, glucagon, emergency levonorgestrel in some jurisdictions, pseudoephedrine combinations). Schedule III: Available in the self-selection ('Lock-and-Leave') area of a pharmacy under direct pharmacist supervision (e.g., ibuprofen 400 mg, naproxen 220 mg). Unscheduled: Can be sold at any retail outlet.

What is the maximum recommended daily dose of Acetaminophen in healthy adults vs. patients with chronic liver disease or chronic alcohol use?

Healthy adults: 4,000 mg/day (4 g/day). Patients with chronic liver disease, cirrhosis, or chronic heavy alcohol intake: limit to ≤2,000 mg/day (2 g/day)—note that low-dose acetaminophen remains safer than NSAIDs in cirrhosis because NSAIDs precipitate hepatorenal syndrome and GI bleeding.

In PEBC Benign Prostatic Hyperplasia (BPH) management, compare Alpha-1 Blockers (tamsulosin, alfuzosin, terazosin) and 5-Alpha-Reductase Inhibitors (finasteride, dutasteride).

Alpha-1 blockers relax smooth muscle in the prostate neck and urethra for rapid symptom relief within days-weeks (tamsulosin/silodosin are uroselective alpha-1A blockers causing less orthostatic hypotension but cause Intraoperative Floppy Iris Syndrome during cataract surgery and retrograde ejaculation). 5-ARIs block conversion of testosterone to DHT, shrinking prostate volume by ~25% over 6 months and halving serum PSA (multiply PSA by 2 after 6 months on finasteride/dutasteride).

In PEBC Infectious Diseases, what is the first-line antibiotic treatment for Uncomplicated Acute Cystitis (UTI) in non-pregnant women in Canada?

1) Nitrofurantoin monohydrate/macrocrystals (MacroBID) 100 mg PO BID for 5 days (contraindicated if CrCl <30 mL/min or at term pregnancy 38–42 weeks), 2) Fosfomycin tromethamine 3 g PO single dose, or 3) TMP-SMX (Septra) 1 DS tablet PO BID for 3 days (if local E. coli resistance <20%). Reserve fluoroquinolones for pyelonephritis.

Which antiepileptic and psychotropic medications carry a heightened risk of Stevens-Johnson Syndrome (SJS) / Toxic Epidermal Necrolysis (TEN), and which HLA allele must be screened in Asian patients before starting Carbamazepine?

Lamotrigine (risk markedly increased if co-prescribed with Valproic acid, which doubles lamotrigine's half-life—requires halved starting dose and slow titration), Carbamazepine, Phenytoin, Allopurinol, and Sulfonamides. Screen for HLA-B*15:02 in patients of Han Chinese or Southeast Asian descent before initiating Carbamazepine.

In PEBC Pharmaceutical Calculations, how many grams of hydrocortisone powder must be added to 120 g of a 1% w/w hydrocortisone cream to increase its concentration to 2.5% w/w?

Using Alligation Alternate (pure powder = 100%, cream = 1%, target = 2.5%): parts of 100% = (2.5 - 1) = 1.5 parts; parts of 1% cream = (100 - 2.5) = 97.5 parts. Mass of powder = (1.5 / 97.5) × 120 g = 1.85 g.

In PEBC Geriatrics (Beers Criteria), why are First-Generation Antihistamines (diphenhydramine, dimenhydrinate, hydroxyzine), Tricyclic Antidepressants (amitriptyline), and Oxybutynin avoided in older adults?

Strong central and peripheral anticholinergic activity ('Can't see, can't pee, can't spit, can't shit') causing delirium, cognitive decline, falls, urinary retention, constipation, and dry mouth.

In PEBC Inhaler Technique counselling, how does the inspiratory breath technique differ between a Metered-Dose Inhaler (MDI) and a Dry Powder Inhaler (DPI, e.g., Turbuhaler, Diskus, Ellipta)?

MDI (with or without spacer): shake well, breathe out, actuate and inhale SLOWLY and deeply over 3–5 seconds, hold breath 10 seconds. DPI: do NOT shake after loading, breathe out away from mouthpiece, inhale QUICKLY, forcefully, and deeply to de-aggregate the powder, hold breath 10 seconds; always rinse mouth and spit after any inhaled corticosteroid (ICS) to prevent oral candidiasis and dysphonia.

In PEBC Biopharmaceutics, what are the regulatory criteria for two oral drug products (Brand vs. Generic) to be declared Bioequivalent by Health Canada?

The 90% confidence interval of the geometric mean ratio (Test/Reference) for AUC (Area Under the Curve—extent of absorption) and the relative mean Cmax (rate of absorption) must fall within 80% to 125% (for Critical Dose Drugs like cyclosporine, digoxin, lithium, phenytoin, tacrolimus, theophylines, warfarin, AUC 90% CI must be 90%–112%).

In PEBC Smoking Cessation counselling, what are the dosing rules for Nicotine Replacement Therapy (NRT Patch + Gum/Lozenge), Varenicline (Champix), and Bupropion SR (Zyban)?

NRT: If smoking ≥10 cigarettes/day (or within 30 min of waking), start 21 mg patch + PRN 2–4 mg gum ('bite and park' technique, avoid acidic beverages 15 min prior). Varenicline (partial α4β2 nicotinic agonist): start 1–2 weeks before quit date (0.5 mg OD × 3d, 0.5 mg BID × 4d, then 1 mg BID × 11 weeks; renally cleared). Bupropion SR: start 1–2 weeks pre-quit, strictly CONTRAINDICATED in seizure disorders, eating disorders (bulimia/anorexia), or abrupt alcohol/benzodiazepine withdrawal.

In PEBC Diabetes Pharmacology, compare the mechanisms, weight effects, hypoglycaemia risks, and signature side effects of GLP-1 Receptor Agonists (semaglutide) vs. SGLT2 Inhibitors (empagliflozin) vs. DPP-4 Inhibitors (sitagliptin/linagliptin).

GLP-1 RAs: glucose-dependent insulin secretion + slowed gastric emptying + satiety → potent weight loss, low hypoglycaemia risk, GI nausea/pancreatitis/MEN2 medullary thyroid C-cell tumour box warning. SGLT2i: block proximal tubule glucose reabsorption → weight loss, BP lowering, CV/HF/CKD protection, genital mycotic infections & euglycaemic DKA. DPP-4i: weight-neutral, low hypoglycaemia, well tolerated (linagliptin requires no renal dose adjustment).

In PEBC Psychiatry, what dietary restriction is mandatory with non-selective irreversible MAO Inhibitors (Phenelzine, Tranylcypromine), and what washout period is required when switching between Fluoxetine and an MAOI?

Avoid high-tyramine foods (aged cheeses, cured/fermented meats, tap/unpasteurized beer, Marmite, soy sauce) to prevent a fatal Hypertensive Crisis. Washout: wait at least 2 weeks when switching from most SSRIs to an MAOI (or MAOI to SSRI), but wait a full 5 WEEKS when switching from Fluoxetine to an MAOI due to norfluoxetine's long half-life (7–15 days).

Under Canada's Controlled Drugs and Substances Act (CDSA) and Narcotic Control Regulations, distinguish Straight Narcotics, Verbal Prescription Narcotics (VPN), Targeted Substances (Benzodiazepines), and Controlled Drugs regarding refills and transfers.

Straight Narcotics (morphine, oxycodone, hydromorphone, fentanyl, methadone): Written/e-script ONLY (no verbal scripts), NO refills permitted (part-fills allowed with total quantity & interval specified), NO transfers (even under temporary CDSA exemptions, strict logging applies). VPNs (codeine preparations with ≥2 non-narcotic ingredients): verbal or written, NO refills, NO transfers. Benzodiazepines/Targeted Substances: verbal or written, refills allowed if within 1 year of prescribing date, 1 transfer allowed. Controlled Drugs (amphetamines, methylphenidate, anabolic steroids, barbiturates): refills allowed if written with interval specified; transfers generally prohibited under standard CDSA rules.

In PEBC Paediatrics, what is the standard weight-based OTC dosing of Acetaminophen vs. Ibuprofen in children, and when is Ibuprofen avoided?

Acetaminophen: 10–15 mg/kg/dose PO every 4–6 hours (max 75 mg/kg/day, not exceeding 5 doses/day or 4,000 mg/day). Ibuprofen: 5–10 mg/kg/dose PO every 6–8 hours (max 40 mg/kg/day)—avoid in infants <6 months, dehydration/gastroenteritis (AKI risk), or varicella (chickenpox—necrotizing fasciitis risk). Never give ASA to children/teens due to Reye syndrome.

In PEBC Sterile Compounding (NAPRA Model Standards), what ISO air quality class is required inside the Primary Engineering Control (Laminar Airflow Workbench / Biological Safety Cabinet), and what does BUD stand for?

ISO Class 5 environment inside the PEC (located within an ISO Class 7 buffer room and ISO Class 8 anteroom). BUD stands for Beyond-Use Date—the date or time after which a compounded sterile or non-sterile preparation must not be used.

How do you calculate the Corrected Phenytoin Concentration (Winter-Tozer equation) in a patient with hypoalbuminaemia (and normal renal function)?

Corrected Phenytoin = Measured Total Phenytoin / [(0.2 × Albumin in g/dL) + 0.1] (or using SI units g/L: Measured / [(0.02 × Albumin in g/L) + 0.1]); halve the 0.2 coefficient to 0.1 if CrCl <10 mL/min.

What is the mechanism of action of Allopurinol vs. Febuxostat vs. Probenecid vs. Rasburicase in Hyperuricaemia and Tumour Lysis Syndrome?

Allopurinol & Febuxostat inhibit Xanthine Oxidase (reducing uric acid synthesis; both drastically increase Azathioprine/6-MP toxicity). Probenecid is a uricosuric agent inhibiting URAT1 tubular reabsorption (ineffective if CrCl <50 mL/min, contraindicated in nephrolithiasis). Rasburicase is recombinant urate oxidase converting existing uric acid into soluble allantoin (contraindicated in G6PD deficiency due to haemolysis/methaemoglobinaemia).

In PEBC Pharmaceutical Calculations, calculate the Sodium Chloride Equivalent (E-value) and grams of NaCl needed to make 60 mL of a 2% w/v solution of Drug X (E-value = 0.20) isotonic with blood (0.9% NaCl).

Total NaCl needed for 60 mL isotonic solution = 60 mL × 0.009 g/mL = 0.54 g. Mass of Drug X = 60 mL × 0.02 g/mL = 1.20 g. NaCl equivalent represented by Drug X = 1.20 g × 0.20 = 0.24 g. Additional NaCl required = 0.54 g - 0.24 g = 0.30 g (300 mg).

What is the role of the Canadian Vigilance Program (MedEffect Canada), and what must hospitals mandatorily report under Vanessa's Law (Protecting Canadians from Unsafe Drugs Act)?

MedEffect Canada collects post-market adverse drug reaction reports; under Vanessa's Law, all Canadian hospitals are legally required to report all Serious Adverse Drug Reactions and Medical Device Incidents to Health Canada within 30 calendar days of documentation.

What does a DIN (Drug Identification Number) vs. NPN (Natural Product Number) on a Canadian health product signify?

An 8-digit DIN issued by Health Canada under the Food and Drug Regulations confirms a pharmaceutical drug has been evaluated for safety, efficacy, and quality. An 8-digit NPN (or DIN-HM for homeopathic products) under the Natural Health Products Regulations confirms licensing as a natural health product (vitamins, minerals, herbals, probiotics).

Which drugs classically cause Drug-Induced Lupus Erythematosus (DILE), and which autoantibody is positive in >95% of cases?

Hydralazine, Procainamide, Isoniazid, Minocycline, Methyldopa, Quinidine, and Anti-TNF biologics ('HIP MMQ'); characterized by anti-histone antibodies.

In PEBC Over-the-Counter (OTC) Counselling, what are the two main oral Emergency Contraception options in Canada, their time windows, and how BMI affects their efficacy?

1) Levonorgestrel 1.5 mg (Plan B—Schedule III/Unscheduled): effective up to 72 hours (up to 120h with declining efficacy), reduced efficacy if BMI ≥25 kg/m² (or weight >75–80 kg). 2) Ulipristal acetate 30 mg (Ella—Prescription/Pharmacist-prescribed): constant high efficacy up to 120 hours (5 days), maintains better efficacy up to BMI 30–35 kg/m²; Copper IUD is the most effective (>99%) emergency contraception up to 7 days post-intercourse regardless of BMI.

In PEBC Pharmacology, compare the mechanisms and adverse effects of ACE Inhibitors (ramipril) vs. ARBs (candersartan) vs. ARNI (sacubitril/valsartan).

ACEi block conversion of Ang I to Ang II and inhibit bradykinin breakdown (causing dry cough in 10–15% and higher angioedema risk). ARBs selectively block AT1 receptors without raising bradykinin. ARNI combines an ARB with neprilysin inhibition (requiring a strict 36-hour washout when switching from/to an ACEi to prevent life-threatening angioedema). All three cause hyperkalaemia, hypotension, and are teratogenic.

What is the mechanism of the Disulfiram-like reaction (flushing, throbbing headache, severe nausea/vomiting, tachycardia), and which drugs require patients to avoid alcohol during and for 48–72 hours after therapy?

Inhibition of aldehyde dehydrogenase causing accumulation of toxic acetaldehyde; classically caused by Metronidazole (and Tinidazole, Cefotetan, or Disulfiram).

In PEBC Infectious Diseases, which oral medications require separation by at least 2 hours before or 4–6 hours after polyvalent cations (Calcium, Iron, Magnesium, Aluminum antacids, Dairy, Sucralfate, Zinc)?

Fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin), Tetracyclines (tetracycline, doxycycline, minocycline), Integrase Inhibitors (bictegravir, dolutegravir, raltegravir), Levothyroxine (separate by 4 hours), and Oral Bisphosphonates.

What is the Cockcroft-Gault equation used in PEBC exams to estimate Creatinine Clearance (CrCl in mL/min) for drug dosing?

CrCl (mL/min) = [(140 - Age in yrs) × Weight in kg × 1.23 (for males) or × 1.04 (for females)] / Serum Creatinine (in µmol/L) [or [(140 - Age) × Weight] / (72 × SCr in mg/dL) × 0.85 for females].

What is the Henderson-Hasselbalch equation for a Weak Acid vs. a Weak Base, and which form crosses lipid biological membranes?

Weak Acid: pH = pKa + log([Ionized A-] / [Unionized HA]). Weak Base: pH = pKa + log([Unionized B] / [Ionized BH+]). Only the UNIONIZED (non-polar, lipid-soluble) fraction readily diffuses across biological membranes; when pH = pKa, the drug is exactly 50% ionized and 50% unionized.

In PEBC Oncology & Supportive Care, what is the triple-therapy prophylactic antiemetic regimen for Highly Emetogenic Chemotherapy (HEC, e.g., Cisplatin)?

5-HT3 receptor antagonist (Ondansetron or Palonosetron) + NK1 receptor antagonist (Aprepitant/Fosaprepitant) + Dexamethasone + Olanzapine.

In PEBC Pharmacokinetics, what are the formulas connecting Elimination Rate Constant (ke), Volume of Distribution (Vd), Clearance (CL), and Elimination Half-Life (t1/2) in a first-order one-compartment model?

CL = ke × Vd; t1/2 = 0.693 / ke = (0.693 × Vd) / CL. Time to reach steady state (Css) is ~4 to 5 half-lives regardless of dose or infusion rate (depends ONLY on t1/2).

How do you calculate an IV Loading Dose (LD) vs. Maintenance Dose Rate (MD) in clinical pharmacokinetics?

Loading Dose = (Target Css × Vd) / (F × S), which depends primarily on Volume of Distribution (Vd). Maintenance Dose Rate = (Target Css × CL) / (F × S), which depends primarily on Clearance (CL).

PEBC Pharmacy Evaluating & Qualifying Exam: Biomedical Sciences, Pharmacology, Pharmaceutical Calculations & Canadian Pharmacy Law (NAPRA)

High-yield Pharmacy Examining Board of Canada (PEBC) Evaluating and Qualifying (Part I MCQ & Part II OSCE) concepts covering pharmaceutical calculations, pharmacokinetics, pharmacology, OTC care, and NAPRA drug schedules.

Level: intermediate
Languages: en → en
Cards: 32
Markdown: PEBC Pharmacy Evaluating & Qualifying Exam: Biomedical Sciences, Pharmacology, Pharmaceutical Calculations & Canadian Pharmacy Law (NAPRA) (.md)

Flashcards (32)

#	Front (Term / Question)	Back (Definition / Answer)
1	Why does Phenytoin exhibit non-linear (Michaelis-Menten / capacity-limited) pharmacokinetics at therapeutic concentrations, and what is the clinical consequence?	Hepatic CYP2C9/2C19 metabolizing enzymes become saturated within the therapeutic range (10–20 mg/L or 40–80 µmol/L), switching kinetics from first-order to zero-order; small increases in daily dose produce disproportionately large, toxic increases in steady-state serum concentration.
2	In PEBC Cardiology, which Statins are classified as High-Intensity (lowering LDL-C by ≥50%), and what are their key drug interactions?	Rosuvastatin 20–40 mg daily and Atorvastatin 40–80 mg daily. Atorvastatin, Simvastatin, and Lovastatin are metabolized by CYP3A4 (avoid grapefruit juice, macrolides, azoles, protease inhibitors); Rosuvastatin and Pravastatin are minimally metabolized by CYP3A4 (safer with CYP3A4 inhibitors). Never combine Gemfibrozil with any statin due to rhabdomyolysis risk (OATP1B1 inhibition).
3	Under the National Association of Pharmacy Regulatory Authorities (NAPRA) National Drug Schedules (NDS) in Canada, define Schedule I, Schedule II, Schedule III, and Unscheduled drugs.	Schedule I: Requires a prescription for sale (dispensed by a pharmacist). Schedule II: Non-prescription ('Behind-the-Counter'—no public self-selection; requires pharmacist intervention/assessment at the counter, e.g., insulin, glucagon, emergency levonorgestrel in some jurisdictions, pseudoephedrine combinations). Schedule III: Available in the self-selection ('Lock-and-Leave') area of a pharmacy under direct pharmacist supervision (e.g., ibuprofen 400 mg, naproxen 220 mg). Unscheduled: Can be sold at any retail outlet.
4	What is the maximum recommended daily dose of Acetaminophen in healthy adults vs. patients with chronic liver disease or chronic alcohol use?	Healthy adults: 4,000 mg/day (4 g/day). Patients with chronic liver disease, cirrhosis, or chronic heavy alcohol intake: limit to ≤2,000 mg/day (2 g/day)—note that low-dose acetaminophen remains safer than NSAIDs in cirrhosis because NSAIDs precipitate hepatorenal syndrome and GI bleeding.
5	In PEBC Benign Prostatic Hyperplasia (BPH) management, compare Alpha-1 Blockers (tamsulosin, alfuzosin, terazosin) and 5-Alpha-Reductase Inhibitors (finasteride, dutasteride).	Alpha-1 blockers relax smooth muscle in the prostate neck and urethra for rapid symptom relief within days-weeks (tamsulosin/silodosin are uroselective alpha-1A blockers causing less orthostatic hypotension but cause Intraoperative Floppy Iris Syndrome during cataract surgery and retrograde ejaculation). 5-ARIs block conversion of testosterone to DHT, shrinking prostate volume by ~25% over 6 months and halving serum PSA (multiply PSA by 2 after 6 months on finasteride/dutasteride).
6	In PEBC Infectious Diseases, what is the first-line antibiotic treatment for Uncomplicated Acute Cystitis (UTI) in non-pregnant women in Canada?	1) Nitrofurantoin monohydrate/macrocrystals (MacroBID) 100 mg PO BID for 5 days (contraindicated if CrCl <30 mL/min or at term pregnancy 38–42 weeks), 2) Fosfomycin tromethamine 3 g PO single dose, or 3) TMP-SMX (Septra) 1 DS tablet PO BID for 3 days (if local E. coli resistance <20%). Reserve fluoroquinolones for pyelonephritis.
7	Which antiepileptic and psychotropic medications carry a heightened risk of Stevens-Johnson Syndrome (SJS) / Toxic Epidermal Necrolysis (TEN), and which HLA allele must be screened in Asian patients before starting Carbamazepine?	Lamotrigine (risk markedly increased if co-prescribed with Valproic acid, which doubles lamotrigine's half-life—requires halved starting dose and slow titration), Carbamazepine, Phenytoin, Allopurinol, and Sulfonamides. Screen for HLA-B*15:02 in patients of Han Chinese or Southeast Asian descent before initiating Carbamazepine.
8	In PEBC Pharmaceutical Calculations, how many grams of hydrocortisone powder must be added to 120 g of a 1% w/w hydrocortisone cream to increase its concentration to 2.5% w/w?	Using Alligation Alternate (pure powder = 100%, cream = 1%, target = 2.5%): parts of 100% = (2.5 - 1) = 1.5 parts; parts of 1% cream = (100 - 2.5) = 97.5 parts. Mass of powder = (1.5 / 97.5) × 120 g = 1.85 g.
9	In PEBC Geriatrics (Beers Criteria), why are First-Generation Antihistamines (diphenhydramine, dimenhydrinate, hydroxyzine), Tricyclic Antidepressants (amitriptyline), and Oxybutynin avoided in older adults?	Strong central and peripheral anticholinergic activity ('Can't see, can't pee, can't spit, can't shit') causing delirium, cognitive decline, falls, urinary retention, constipation, and dry mouth.
10	In PEBC Inhaler Technique counselling, how does the inspiratory breath technique differ between a Metered-Dose Inhaler (MDI) and a Dry Powder Inhaler (DPI, e.g., Turbuhaler, Diskus, Ellipta)?	MDI (with or without spacer): shake well, breathe out, actuate and inhale SLOWLY and deeply over 3–5 seconds, hold breath 10 seconds. DPI: do NOT shake after loading, breathe out away from mouthpiece, inhale QUICKLY, forcefully, and deeply to de-aggregate the powder, hold breath 10 seconds; always rinse mouth and spit after any inhaled corticosteroid (ICS) to prevent oral candidiasis and dysphonia.
11	In PEBC Biopharmaceutics, what are the regulatory criteria for two oral drug products (Brand vs. Generic) to be declared Bioequivalent by Health Canada?	The 90% confidence interval of the geometric mean ratio (Test/Reference) for AUC (Area Under the Curve—extent of absorption) and the relative mean Cmax (rate of absorption) must fall within 80% to 125% (for Critical Dose Drugs like cyclosporine, digoxin, lithium, phenytoin, tacrolimus, theophylines, warfarin, AUC 90% CI must be 90%–112%).
12	In PEBC Smoking Cessation counselling, what are the dosing rules for Nicotine Replacement Therapy (NRT Patch + Gum/Lozenge), Varenicline (Champix), and Bupropion SR (Zyban)?	NRT: If smoking ≥10 cigarettes/day (or within 30 min of waking), start 21 mg patch + PRN 2–4 mg gum ('bite and park' technique, avoid acidic beverages 15 min prior). Varenicline (partial α4β2 nicotinic agonist): start 1–2 weeks before quit date (0.5 mg OD × 3d, 0.5 mg BID × 4d, then 1 mg BID × 11 weeks; renally cleared). Bupropion SR: start 1–2 weeks pre-quit, strictly CONTRAINDICATED in seizure disorders, eating disorders (bulimia/anorexia), or abrupt alcohol/benzodiazepine withdrawal.
13	In PEBC Diabetes Pharmacology, compare the mechanisms, weight effects, hypoglycaemia risks, and signature side effects of GLP-1 Receptor Agonists (semaglutide) vs. SGLT2 Inhibitors (empagliflozin) vs. DPP-4 Inhibitors (sitagliptin/linagliptin).	GLP-1 RAs: glucose-dependent insulin secretion + slowed gastric emptying + satiety → potent weight loss, low hypoglycaemia risk, GI nausea/pancreatitis/MEN2 medullary thyroid C-cell tumour box warning. SGLT2i: block proximal tubule glucose reabsorption → weight loss, BP lowering, CV/HF/CKD protection, genital mycotic infections & euglycaemic DKA. DPP-4i: weight-neutral, low hypoglycaemia, well tolerated (linagliptin requires no renal dose adjustment).
14	In PEBC Psychiatry, what dietary restriction is mandatory with non-selective irreversible MAO Inhibitors (Phenelzine, Tranylcypromine), and what washout period is required when switching between Fluoxetine and an MAOI?	Avoid high-tyramine foods (aged cheeses, cured/fermented meats, tap/unpasteurized beer, Marmite, soy sauce) to prevent a fatal Hypertensive Crisis. Washout: wait at least 2 weeks when switching from most SSRIs to an MAOI (or MAOI to SSRI), but wait a full 5 WEEKS when switching from Fluoxetine to an MAOI due to norfluoxetine's long half-life (7–15 days).
15	Under Canada's Controlled Drugs and Substances Act (CDSA) and Narcotic Control Regulations, distinguish Straight Narcotics, Verbal Prescription Narcotics (VPN), Targeted Substances (Benzodiazepines), and Controlled Drugs regarding refills and transfers.	Straight Narcotics (morphine, oxycodone, hydromorphone, fentanyl, methadone): Written/e-script ONLY (no verbal scripts), NO refills permitted (part-fills allowed with total quantity & interval specified), NO transfers (even under temporary CDSA exemptions, strict logging applies). VPNs (codeine preparations with ≥2 non-narcotic ingredients): verbal or written, NO refills, NO transfers. Benzodiazepines/Targeted Substances: verbal or written, refills allowed if within 1 year of prescribing date, 1 transfer allowed. Controlled Drugs (amphetamines, methylphenidate, anabolic steroids, barbiturates): refills allowed if written with interval specified; transfers generally prohibited under standard CDSA rules.
16	In PEBC Paediatrics, what is the standard weight-based OTC dosing of Acetaminophen vs. Ibuprofen in children, and when is Ibuprofen avoided?	Acetaminophen: 10–15 mg/kg/dose PO every 4–6 hours (max 75 mg/kg/day, not exceeding 5 doses/day or 4,000 mg/day). Ibuprofen: 5–10 mg/kg/dose PO every 6–8 hours (max 40 mg/kg/day)—avoid in infants <6 months, dehydration/gastroenteritis (AKI risk), or varicella (chickenpox—necrotizing fasciitis risk). Never give ASA to children/teens due to Reye syndrome.
17	In PEBC Sterile Compounding (NAPRA Model Standards), what ISO air quality class is required inside the Primary Engineering Control (Laminar Airflow Workbench / Biological Safety Cabinet), and what does BUD stand for?	ISO Class 5 environment inside the PEC (located within an ISO Class 7 buffer room and ISO Class 8 anteroom). BUD stands for Beyond-Use Date—the date or time after which a compounded sterile or non-sterile preparation must not be used.
18	How do you calculate the Corrected Phenytoin Concentration (Winter-Tozer equation) in a patient with hypoalbuminaemia (and normal renal function)?	Corrected Phenytoin = Measured Total Phenytoin / [(0.2 × Albumin in g/dL) + 0.1] (or using SI units g/L: Measured / [(0.02 × Albumin in g/L) + 0.1]); halve the 0.2 coefficient to 0.1 if CrCl <10 mL/min.
19	What is the mechanism of action of Allopurinol vs. Febuxostat vs. Probenecid vs. Rasburicase in Hyperuricaemia and Tumour Lysis Syndrome?	Allopurinol & Febuxostat inhibit Xanthine Oxidase (reducing uric acid synthesis; both drastically increase Azathioprine/6-MP toxicity). Probenecid is a uricosuric agent inhibiting URAT1 tubular reabsorption (ineffective if CrCl <50 mL/min, contraindicated in nephrolithiasis). Rasburicase is recombinant urate oxidase converting existing uric acid into soluble allantoin (contraindicated in G6PD deficiency due to haemolysis/methaemoglobinaemia).
20	In PEBC Pharmaceutical Calculations, calculate the Sodium Chloride Equivalent (E-value) and grams of NaCl needed to make 60 mL of a 2% w/v solution of Drug X (E-value = 0.20) isotonic with blood (0.9% NaCl).	Total NaCl needed for 60 mL isotonic solution = 60 mL × 0.009 g/mL = 0.54 g. Mass of Drug X = 60 mL × 0.02 g/mL = 1.20 g. NaCl equivalent represented by Drug X = 1.20 g × 0.20 = 0.24 g. Additional NaCl required = 0.54 g - 0.24 g = 0.30 g (300 mg).
21	What is the role of the Canadian Vigilance Program (MedEffect Canada), and what must hospitals mandatorily report under Vanessa's Law (Protecting Canadians from Unsafe Drugs Act)?	MedEffect Canada collects post-market adverse drug reaction reports; under Vanessa's Law, all Canadian hospitals are legally required to report all Serious Adverse Drug Reactions and Medical Device Incidents to Health Canada within 30 calendar days of documentation.
22	What does a DIN (Drug Identification Number) vs. NPN (Natural Product Number) on a Canadian health product signify?	An 8-digit DIN issued by Health Canada under the Food and Drug Regulations confirms a pharmaceutical drug has been evaluated for safety, efficacy, and quality. An 8-digit NPN (or DIN-HM for homeopathic products) under the Natural Health Products Regulations confirms licensing as a natural health product (vitamins, minerals, herbals, probiotics).
23	Which drugs classically cause Drug-Induced Lupus Erythematosus (DILE), and which autoantibody is positive in >95% of cases?	Hydralazine, Procainamide, Isoniazid, Minocycline, Methyldopa, Quinidine, and Anti-TNF biologics ('HIP MMQ'); characterized by anti-histone antibodies.
24	In PEBC Over-the-Counter (OTC) Counselling, what are the two main oral Emergency Contraception options in Canada, their time windows, and how BMI affects their efficacy?	1) Levonorgestrel 1.5 mg (Plan B—Schedule III/Unscheduled): effective up to 72 hours (up to 120h with declining efficacy), reduced efficacy if BMI ≥25 kg/m² (or weight >75–80 kg). 2) Ulipristal acetate 30 mg (Ella—Prescription/Pharmacist-prescribed): constant high efficacy up to 120 hours (5 days), maintains better efficacy up to BMI 30–35 kg/m²; Copper IUD is the most effective (>99%) emergency contraception up to 7 days post-intercourse regardless of BMI.
25	In PEBC Pharmacology, compare the mechanisms and adverse effects of ACE Inhibitors (ramipril) vs. ARBs (candersartan) vs. ARNI (sacubitril/valsartan).	ACEi block conversion of Ang I to Ang II and inhibit bradykinin breakdown (causing dry cough in 10–15% and higher angioedema risk). ARBs selectively block AT1 receptors without raising bradykinin. ARNI combines an ARB with neprilysin inhibition (requiring a strict 36-hour washout when switching from/to an ACEi to prevent life-threatening angioedema). All three cause hyperkalaemia, hypotension, and are teratogenic.
26	What is the mechanism of the Disulfiram-like reaction (flushing, throbbing headache, severe nausea/vomiting, tachycardia), and which drugs require patients to avoid alcohol during and for 48–72 hours after therapy?	Inhibition of aldehyde dehydrogenase causing accumulation of toxic acetaldehyde; classically caused by Metronidazole (and Tinidazole, Cefotetan, or Disulfiram).
27	In PEBC Infectious Diseases, which oral medications require separation by at least 2 hours before or 4–6 hours after polyvalent cations (Calcium, Iron, Magnesium, Aluminum antacids, Dairy, Sucralfate, Zinc)?	Fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin), Tetracyclines (tetracycline, doxycycline, minocycline), Integrase Inhibitors (bictegravir, dolutegravir, raltegravir), Levothyroxine (separate by 4 hours), and Oral Bisphosphonates.
28	What is the Cockcroft-Gault equation used in PEBC exams to estimate Creatinine Clearance (CrCl in mL/min) for drug dosing?	CrCl (mL/min) = [(140 - Age in yrs) × Weight in kg × 1.23 (for males) or × 1.04 (for females)] / Serum Creatinine (in µmol/L) [or [(140 - Age) × Weight] / (72 × SCr in mg/dL) × 0.85 for females].
29	What is the Henderson-Hasselbalch equation for a Weak Acid vs. a Weak Base, and which form crosses lipid biological membranes?	Weak Acid: pH = pKa + log([Ionized A-] / [Unionized HA]). Weak Base: pH = pKa + log([Unionized B] / [Ionized BH+]). Only the UNIONIZED (non-polar, lipid-soluble) fraction readily diffuses across biological membranes; when pH = pKa, the drug is exactly 50% ionized and 50% unionized.
30	In PEBC Oncology & Supportive Care, what is the triple-therapy prophylactic antiemetic regimen for Highly Emetogenic Chemotherapy (HEC, e.g., Cisplatin)?	5-HT3 receptor antagonist (Ondansetron or Palonosetron) + NK1 receptor antagonist (Aprepitant/Fosaprepitant) + Dexamethasone + Olanzapine.
31	In PEBC Pharmacokinetics, what are the formulas connecting Elimination Rate Constant (ke), Volume of Distribution (Vd), Clearance (CL), and Elimination Half-Life (t1/2) in a first-order one-compartment model?	CL = ke × Vd; t1/2 = 0.693 / ke = (0.693 × Vd) / CL. Time to reach steady state (Css) is ~4 to 5 half-lives regardless of dose or infusion rate (depends ONLY on t1/2).
32	How do you calculate an IV Loading Dose (LD) vs. Maintenance Dose Rate (MD) in clinical pharmacokinetics?	Loading Dose = (Target Css × Vd) / (F × S), which depends primarily on Volume of Distribution (Vd). Maintenance Dose Rate = (Target Css × CL) / (F × S), which depends primarily on Clearance (CL).