PEBC Part I (MCQ) cheat sheet

Henderson-Hasselbalch: pH = pKa + log([A-]/[HA]); for a weak base, use the pKa of its conjugate acid.

Renal clearance: C = (U x V)/P, where U is urine concentration, V is urine flow, and P is plasma concentration; inulin clearance estimates GFR.

Cardiac output = heart rate x stroke volume; mean arterial pressure is approximately diastolic pressure plus one-third of pulse pressure.

Cardiac action potential: rapid sodium influx causes depolarization, calcium influx produces the plateau, and potassium efflux causes repolarization.

IgG crosses the placenta and fixes complement; IgM is the first antibody in a primary response; IgA dominates secretions; IgE mediates type I hypersensitivity.

Gram-positive bacteria have thick peptidoglycan; Gram-negative bacteria have an outer membrane containing lipopolysaccharide endotoxin; mycobacteria are acid-fast due to mycolic acids.

Competitive inhibitors increase Km without changing Vmax; noncompetitive inhibitors decrease Vmax without changing Km.

CYP450 induction increases metabolism and can lower substrate concentrations; CYP450 inhibition raises substrate concentrations and toxicity risk.

First-order elimination: half-life = 0.693/K; steady state is reached after about four to five half-lives.

Vd = amount of drug in body / plasma concentration; clearance CL = K x Vd; loading dose = (Vd x target concentration)/bioavailability.

Oral bioavailability F = (AUC oral/AUC intravenous) x (dose intravenous/dose oral).

Zero-order elimination removes a constant amount per time; half-life is not constant and is common with ethanol and high-dose phenytoin.

Michaelis-Menten: v = Vmax[S]/(Km + [S]); at [S] much greater than Km the process is zero-order, and at [S] much less than Km it is first-order.

Prodrugs require biotransformation for activity; enalapril is hydrolyzed to enalaprilat, and codeine is metabolized to morphine.

pH partition: weak acids ionize more at high pH, weak bases ionize more at low pH, and ionized forms are less lipid permeable.

Bioisosteres replace functional groups with similar physicochemical properties; salt formation changes solubility and stability but not intrinsic receptor activity.

Warfarin: monitor INR; target is usually 2.0 to 3.0, and 2.5 to 3.5 for mechanical mitral valves.

ACE inhibitors: monitor potassium and creatinine; contraindicated in pregnancy; cough is linked to bradykinin accumulation.

Metformin: first-line for type 2 diabetes unless eGFR is below 30 mL/min/1.73 m2; hold around iodinated contrast when acute kidney injury risk is present.

Asthma: inhaled corticosteroid is the preferred controller; a long-acting beta-2 agonist is added only with an inhaled corticosteroid, never as monotherapy.

Heart failure with reduced ejection fraction: guideline-directed therapy includes ARNI or ACE inhibitor/ARB, beta-blocker, mineralocorticoid receptor antagonist, and SGLT2 inhibitor.

Vancomycin: AUC/MIC monitoring is preferred; rapid infusion can cause red man syndrome; nephrotoxicity risk rises with high exposure and concurrent nephrotoxins.

Opioids: assess sedation and respiratory rate; naloxone reverses overdose; constipation does not resolve with tolerance, so a bowel regimen is needed.

Antimicrobial de-escalation: narrow therapy based on culture and susceptibility results, use evidence-based durations, and avoid unnecessary broad-spectrum exposure.

Alligation: ratio of high-strength to low-strength parts = (desired - low):(high - desired), with all concentrations in the same units.

Dilution: C1 x V1 = C2 x V2; the total amount of drug remains constant.

Percent w/v means grams per 100 mL; percent v/v means milliliters per 100 mL; percent w/w means grams per 100 g.

Milliequivalents: mEq = (mg x valence)/molecular weight; use for electrolyte replacement and solution composition.

Sodium chloride equivalent: sum the E value times grams for each ingredient, then add sodium chloride to reach 0.9% tonicity.

Cockcroft-Gault: creatinine clearance = ((140 - age) x weight)/(72 x serum creatinine), multiplied by 0.85 for female patients.

IV flow rate: mL/h = total volume/total hours; drops/min = (volume x drop factor)/time in minutes.

Compounding beyond-use dates depend on water content, preservative, storage, and risk level; a manufacturer expiry date cannot be extended after mixing.

Canadian pharmacy regulation: provincial and territorial colleges license pharmacists and set practice standards; federal law regulates drug marketing, safety, and efficacy.

Controlled drugs require secure storage, accurate records, and prescription retention; federal schedules and provincial college rules both apply.

Prescription requirements generally include patient identifiers, prescriber information, drug name, strength, quantity, directions, and date.

Informed consent requires capacity, voluntary choice, disclosure of material risks and benefits, and understanding; substitute decision-makers act when capacity is absent.

Confidentiality: disclose personal health information only with consent or legal authority, and share the minimum necessary for care.

Conflict of interest: declare gifts, relationships, and financial interests; avoid arrangements that influence clinical decisions or professional judgment.

Medication incidents should be reported, disclosed to the patient when appropriate, and analyzed for system causes rather than individual blame.

Canada prohibits direct-to-consumer advertising of prescription drugs; reminder advertising is restricted to name, price, quantity, and similar non-promotional information.

Prescription validation checks patient identifiers, prescriber authority, drug and dose, directions, allergies, interactions, and duplicate therapy.

Dispensing labels include patient name, drug, strength, quantity, directions, date, and auxiliary warnings; calculations should be independently verified.

High-alert medications include insulin, heparin, opioids, chemotherapy, and concentrated electrolytes; use independent double-checks and standardized concentrations.

Tall man lettering reduces look-alike/sound-alike errors, such as hydrOXYzine versus hydrALAZINE.

Medication reconciliation obtains the best possible medication history, compares it with current orders at transitions, and resolves discrepancies.

Medication error types include prescribing, transcribing, dispensing, administration, and monitoring errors; systems analysis targets latent causes.

Refrigerated drugs are stored at 2 to 8 degrees Celsius; room temperature is 15 to 30 degrees Celsius; protect light-sensitive drugs and avoid freezing unless labeled.

Recalled or expired stock should be quarantined, documented, and segregated; patient notification is required when a recalled product reached the patient.

Health belief model: perceived susceptibility, severity, benefits, barriers, cues to action, and self-efficacy predict preventive behavior.

Transtheoretical model stages: precontemplation, contemplation, preparation, action, maintenance, and possible relapse; match interventions to stage.

Social determinants of health include income, education, housing, food security, and social support; these affect adherence and health outcomes.

Adherence can be measured by pill counts, refill records, and self-report; each method has limitations and no single gold standard exists.

Motivational interviewing uses open questions, affirmations, reflections, and summaries; it supports autonomy and rolls with resistance.

Pharmacoeconomic analyses include cost-minimization, cost-effectiveness, cost-utility, and cost-benefit; ICER = incremental cost/incremental effect.

Inventory management uses ABC analysis, economic order quantity, and safety stock to balance carrying costs against stockouts.

Quality improvement often uses Plan-Do-Study-Act cycles; measure processes and outcomes, then test small changes before spread.

Teach-back asks patients to explain instructions in their own words; it confirms understanding and reveals gaps without shaming.

Health literacy universal precautions: use plain language, limit key points, use pictures, and avoid jargon for every patient.

SBAR structures handover as Situation, Background, Assessment, and Recommendation; ISBAR adds Identification.

Interprofessional collaboration requires role clarity, shared goals, mutual respect, and structured communication.

Cultural safety recognizes power differences and historical context; use qualified interpreters and patient-centered decision-making.

Documentation should be objective, timely, and accurate; record counseling, consent, and follow-up plans.

Medication counseling covers indication, dose, timing, duration, common adverse effects, missed doses, and storage.

Conflict resolution in teams uses active listening, neutral language, and focus on patient safety rather than personal blame.

Primary prevention acts before disease occurs; secondary prevention detects early disease; tertiary prevention limits disability and complications.

Herd immunity threshold is approximately 1 - 1/R0; higher R0 requires a larger immune fraction to interrupt transmission.

Screening criteria include an important condition, detectable early stage, acceptable test, effective treatment, and acceptable cost.

Live vaccines are generally contraindicated in pregnancy and severe immunosuppression; inactivated vaccines can usually be given.

Notifiable diseases include measles, tuberculosis, gonorrhea, and foodborne outbreaks; report to public health authorities.

Ottawa Charter actions: build healthy public policy, create supportive environments, strengthen community action, develop personal skills, and reorient health services.

Smoking cessation combines counseling with pharmacotherapy such as nicotine replacement, varenicline, or bupropion.

Antimicrobial stewardship includes appropriate prescribing, infection prevention, public education, and surveillance of resistance.

Evidence hierarchy: systematic reviews and meta-analyses, randomized trials, cohort studies, case-control studies, cross-sectional studies, case reports, expert opinion.

Randomization reduces selection bias; blinding reduces performance and detection bias; intention-to-treat preserves randomization.

Sensitivity = TP/(TP + FN); specificity = TN/(TN + FP); positive predictive value depends on disease prevalence.

Number needed to treat = 1/absolute risk reduction; absolute risk reduction = control event rate - treatment event rate.

A 95% confidence interval excluding the null value suggests statistical significance at alpha 0.05; width reflects precision.

A p-value is the probability of the observed or more extreme result if the null hypothesis is true; it is not the probability that the null is true.

Meta-analysis assesses heterogeneity with I-squared and publication bias with funnel plots and Egger tests.

Computerized provider order entry reduces prescribing errors; clinical decision support alerts can cause fatigue and should be optimized.