OMSB Pharmacist Exam flashcards

31 cards. Read the term and the definition here. The deck at the top of this page is optional.

First-order half-life formula

For first-order elimination, half-life equals 0.693 divided by the elimination rate constant k. Half-life is constant regardless of dose or concentration, and about four to five half-lives are needed to reach steady state.

Volume of distribution

Vd equals the amount of drug in the body divided by plasma concentration. It estimates the apparent space the drug occupies; large Vd means extensive tissue distribution and less removal by dialysis.

Loading dose calculation

Loading dose equals Vd multiplied by target plasma concentration, divided by bioavailability. It fills the apparent distribution volume rapidly; maintenance dosing then replaces eliminated drug at the clearance rate.

Zero-order elimination

A constant amount of drug is eliminated per unit time because enzymes are saturated. Half-life increases with concentration and dose; examples include ethanol, phenytoin at high doses, and high-dose salicylates.

Bioavailability and first-pass effect

Bioavailability is the fraction of an administered dose reaching systemic circulation intact. Oral drugs undergo hepatic first-pass metabolism, reducing bioavailability; intravenous administration has 100 percent bioavailability by definition.

Prodrug activation examples

A prodrug is inactive until metabolized. Examples include enalapril to enalaprilat, codeine to morphine, clopidogrel to its active thiol metabolite, and valacyclovir to acyclovir, improving absorption or stability.

Ion trapping of weak acids

Weak acid drugs are largely ionized in alkaline urine, which reduces tubular reabsorption and increases renal elimination. Alkalinizing urine can accelerate salicylate or phenobarbital removal in overdose.

Enantiomer potency differences

Stereoisomers can differ markedly in activity. S-warfarin is several times more potent than R-warfarin as a vitamin K antagonist, and S-methacholine is far more active than its R-isomer.

Warfarin INR targets

Most indications, including atrial fibrillation and venous thromboembolism, target INR 2 to 3. Mechanical mitral valves target 2.5 to 3.5. Bridging with heparin is used when INR is subtherapeutic in high-risk patients.

Digoxin toxicity features

Toxicity causes nausea, anorexia, confusion, yellow-green visual halos, and bradyarrhythmias. Risk increases with hypokalemia, hypomagnesemia, hypercalcemia, renal impairment, and interacting drugs such as amiodarone and verapamil.

ACE inhibitor adverse effects

ACE inhibitors cause hyperkalemia, creatinine rise, dry cough from bradykinin accumulation, and angioedema. They are contraindicated in pregnancy and bilateral renal artery stenosis and require potassium monitoring.

Metformin key cautions

Metformin is first-line for type 2 diabetes and causes gastrointestinal upset and lactic acidosis rarely. Hold during acute illness or before iodinated contrast when eGFR is below 30; monitor vitamin B12 with long-term use.

Asthma stepwise therapy

Treatment escalates from as-needed short-acting beta-agonist to low-dose inhaled corticosteroid, then combination with long-acting beta-agonist or medium-dose steroid. Long-acting beta-agonists are never used alone in asthma.

Heart failure four pillars

For heart failure with reduced ejection fraction, combine an ARNI, ACE inhibitor, or ARB with an evidence-based beta-blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor. Loop diuretics relieve congestion.

Vancomycin monitoring target

For serious MRSA infection, target an AUC24 over MIC of 400 to 600. Trough-only monitoring is less preferred. Red man syndrome is an infusion-rate reaction, not a true allergy.

Aminoglycoside monitoring

Aminoglycosides show concentration-dependent killing and a post-antibiotic effect. Monitor trough concentrations or AUC, renal function, and hearing; main toxicities are nephrotoxicity and vestibular or cochlear ototoxicity.

Opioid rotation principle

Convert doses using equianalgesic tables, then reduce the calculated new opioid dose by 25 to 50 percent to account for incomplete cross-tolerance, and titrate to effect with monitoring.

Medication reconciliation points

Reconcile medications at admission, transfer, and discharge. Compare the best possible medication history with current orders, resolve discrepancies with the prescriber, and communicate the final list to the next care setting.

Naranjo causality scale

The Naranjo scale scores adverse drug reaction causality as definite, probable, possible, or doubtful using structured questions about timing, dechallenge, rechallenge, alternative causes, and prior reports.

High-alert medication safeguards

High-alert drugs such as insulin, heparin, concentrated electrolytes, chemotherapy, and opioids require standardized concentrations, independent double-checks, clear labeling, and restricted access storage to prevent harm.

Antimicrobial stewardship core

Stewardship promotes the right drug, dose, route, and duration. Core strategies include prospective audit with feedback, formulary restriction, de-escalation based on cultures, and intravenous-to-oral conversion.

Therapeutic drug monitoring criteria

TDM suits drugs with a narrow therapeutic index, established concentration-effect relationship, and unpredictable pharmacokinetics. Examples include vancomycin, aminoglycosides, digoxin, lithium, phenytoin, and cyclosporine.

Pharmacogenomic pre-treatment tests

Test HLA-B*5701 before abacavir to prevent hypersensitivity, HLA-B*1502 before carbamazepine in at-risk populations, and TPMT or NUDT15 before thiopurines to avoid severe myelosuppression.

Valid prescription elements

A valid prescription identifies prescriber and patient, drug, strength, dosage form, quantity, directions, and date, with the prescriber signature. Missing or ambiguous elements require clarification before dispensing.

Inhaler technique counselling

Shake the device, exhale fully, seal lips, actuate at the start of a slow deep inhalation, and hold breath about ten seconds. Rinse the mouth after inhaled corticosteroids; use a spacer if coordination is poor.

Warfarin patient counselling

Advise consistent vitamin K intake, avoiding NSAIDs and interacting drugs, reporting bleeding or bruising, carrying an anticoagulant card, and attending regular INR checks. Emphasize that dose changes follow INR results.

Insulin storage and injection

Unopened insulin vials are refrigerated and never frozen. In-use pens or vials stay at room temperature for the labeled period. Rotate injection sites within one region to prevent lipohypertrophy and erratic absorption.

Bisphosphonate administration rules

Take oral bisphosphonates on an empty stomach with a full glass of plain water, remain upright for at least 30 minutes, and avoid food, calcium, or other drugs for 30 to 60 minutes to ensure absorption.

Controlled drug schedule concept

Controlled substances are scheduled by abuse potential and accepted medical use. Higher schedules carry stricter prescribing limits, storage, record-keeping, and dispensing requirements defined by national law.

Duty to disclose errors

Pharmacists should document dispensing errors and near misses, inform the patient when harm occurs, and report through appropriate channels. Disclosure is an ethical duty and often a legal requirement.

Confidentiality limits

Patient information is confidential and shared only on a need-to-know basis. Disclosure without consent is permitted only where legally required or justified, such as court orders or serious public health risk.