Free OPRA Exam Flashcards

Homeostasis is the body's stable internal balance (temperature, pH, fluid/electrolyte levels). Vital sign changes usually signal a homeostatic mechanism struggling to compensate — recognising the disrupted parameter points to the underlying disease process.

A negative feedback loop senses a change from the set point and triggers a response that reverses it (e.g., rising blood glucose triggers insulin release to lower it). When the loop fails, the variable drifts uncontrolled — the basis of many chronic disease states.

qSOFA (quick Sequential Organ Failure Assessment) and SIRS (Systemic Inflammatory Response Syndrome) are rapid screening tools using vitals (respiratory rate, blood pressure, mental status, temperature, heart rate) to flag patients at risk of sepsis needing urgent escalation.

The body tightly controls blood pH, CO2 (respiratory component), and bicarbonate (metabolic component). Disturbances (acidosis/alkalosis) alter drug ionisation, renal excretion, and electrolyte handling, changing how some medicines behave.

Sodium, potassium, and calcium are the electrolytes most frequently disturbed by medicines (e.g., diuretics lowering potassium, ACE inhibitors raising it). Imbalances can cause arrhythmias, muscle weakness, or confusion, so monitoring is essential with high-risk drug classes.

Gram-positive bacteria have a thick peptidoglycan wall that retains crystal violet stain, appearing purple; Gram-negative bacteria have a thinner wall plus an outer membrane, staining pink. This distinction predicts likely antibiotic susceptibility and mechanism of action.

Innate immunity is fast and non-specific (skin barrier, phagocytes, inflammation) and acts within minutes to hours. Adaptive immunity is slower to develop but specific and memory-based (T cells, B cells, antibodies), giving lasting protection after exposure or vaccination.

Bacteria resist antibiotics by producing enzymes that inactivate the drug (e.g., beta-lactamase), pumping the drug out via efflux pumps, or altering the drug's target site so it no longer binds effectively.

Live attenuated (weakened whole organism), inactivated (killed organism), subunit (isolated antigen fragment), and mRNA (genetic instructions for the body to make the antigen itself) — each triggers an immune response by a different route, affecting durability and safety profile.

CRP (C-reactive protein), ESR (erythrocyte sedimentation rate), and WCC (white cell count) commonly rise with inflammation or infection. They support clinical judgement but are non-specific — none alone confirms a diagnosis.

Bioavailability is the fraction of an administered dose that reaches systemic circulation unchanged. IV doses have 100% bioavailability by definition; oral doses are usually lower due to incomplete absorption and first-pass metabolism.

Orally absorbed drugs pass through the portal vein to the liver before reaching systemic circulation — first-pass metabolism can inactivate a large fraction before it acts, so the oral dose must be higher to achieve the same effect.

Enteric coating resists dissolution in stomach acid and only dissolves in the intestine's higher pH. It protects acid-labile drugs from destruction and/or protects the stomach lining from irritant drugs.

Sustained-release formulations slow drug release over time, producing steadier blood levels and allowing less frequent dosing — but they must not be crushed or split, as this can destroy the release mechanism and cause dangerous dose dumping.

Solubility depends on factors like pH, particle size, and temperature. Stability describes a drug's resistance to degradation over time — poor stability can reduce potency or create toxic breakdown products, which is why storage conditions and expiry dates matter at dispensing.

ADME stands for Absorption, Distribution, Metabolism, and Excretion — the sequence a drug follows from entering the body, spreading through tissues, being chemically transformed (mainly by the liver), and finally being eliminated (mainly by the kidneys or bile).

Half-life is the time needed for a drug's plasma concentration to fall by half. It takes roughly 4-5 half-lives to reach steady state (and roughly the same to fully clear the drug), which is why loading doses are used for drugs with long half-lives.

Volume of distribution (Vd) is an apparent value relating dose to plasma concentration. A high Vd suggests the drug is extensively distributed into tissues rather than staying in the blood, which matters for dosing and for dialysis removal in overdose.

In first-order kinetics, a constant fraction of drug is eliminated per unit time (most drugs). In zero-order kinetics, a constant amount is eliminated regardless of concentration, because elimination pathways are saturated — small dose increases can cause disproportionate toxicity.

Therapeutic index compares the toxic dose to the effective dose. A narrow therapeutic index means the toxic and effective doses are close together, requiring close monitoring (e.g., levels, clinical signs) to avoid under- or over-dosing.

This is a Type A ADR — predictable, dose-related, and an extension of the drug's known pharmacological effect. Type B ADRs are unpredictable and idiosyncratic (e.g., an allergic reaction), unrelated to dose.

A CYP450 inhibitor slows metabolism of drugs sharing that pathway, raising their blood levels and toxicity risk. A CYP450 inducer speeds up metabolism, lowering levels and potentially causing therapeutic failure — the opposite clinical risk.

Combining an SSRI (or other serotonergic drug) with an MAOI is a classic high-risk pairing for serotonin syndrome — a potentially life-threatening excess of serotonergic activity causing agitation, hyperthermia, and neuromuscular changes.

Multiple QT-prolonging drugs combined increase the risk of torsades de pointes, a dangerous ventricular arrhythmia. Screening for cumulative QT risk is a key medicines-safety check, especially in patients with other risk factors (electrolyte imbalance, cardiac disease).

N-acetylcysteine (NAC) is the antidote for paracetamol overdose — it replenishes glutathione stores to detoxify the toxic metabolite NAPQI before it causes hepatic damage.

Naloxone reverses opioid overdose by displacing opioids from receptors. Its effect can wear off before the opioid does (especially long-acting opioids), so ongoing monitoring and repeat dosing may be needed.

Flumazenil can precipitate seizures, particularly in patients who are benzodiazepine-dependent or who have co-ingested pro-convulsant drugs (e.g., tricyclic antidepressants), so its use is reserved for select, carefully monitored cases.

Iron overdose → desferrioxamine (chelates iron). Warfarin overdose/bleeding → vitamin K (restores clotting factor synthesis). Organophosphate/nerve agent poisoning → atropine (blocks excess cholinergic activity).

The Pharmaceutical Benefits Scheme (PBS) subsidises the cost of listed prescription medicines in Australia, so patients pay only a co-payment rather than the full price — making essential medicines affordable and accessible.

The general co-payment is up to AU$25 per script for patients without a concession card. The concessional co-payment is a lower fixed amount, AU$7.70 per script, for concession card holders — card status determines which fee applies.

Once a patient's PBS co-payments reach the annual Safety Net threshold (AU$1,748.20 general, AU$277.20 concessional in 2026), further PBS scripts become cheaper or free for the rest of the calendar year — concessional patients pay nothing further.

An authority prescription is required — the prescriber must obtain PBS approval confirming the patient meets the restricted criteria before the medicine can be dispensed at the subsidised price.

Repeats let the patient receive further supplies of the same medicine without a new prescription, up to the authorised number and within the repeat's validity period. It does not allow dose changes or substitution of an unrelated medicine.

Yes — S2 (Pharmacy Medicine) can be self-selected by the customer, though it must be sold from a pharmacy and pharmacist advice must be available. S3 (Pharmacist Only) requires direct pharmacist involvement in the supply.

S4 (Prescription Only Medicine) requires a valid prescription from an authorised prescriber before it can be dispensed. S3 can be supplied by a pharmacist's own judgement without a script.

S8 (Controlled Drug) medicines have recognised addiction/abuse/misuse potential (e.g., opioids, some stimulants), so they require additional legal controls — running balances, register entries, and often state-based authority for prolonged supply — beyond standard S4 requirements.

S9 (Prohibited Substance) is banned from general sale, supply, and use except for limited research or government-approved purposes. Unlike S8 (available via legitimate prescription with controls), S9 has no accepted therapeutic supply pathway in ordinary practice.

The SUSMP (Standard for the Uniform Scheduling of Medicines and Poisons), also called the Poisons Standard, published by the TGA, is the authoritative reference for classifying every scheduled substance in Australia.

AHPRA (Australian Health Practitioner Regulation Agency) administers national registration and handles notifications (complaints about conduct, health, or performance) across all regulated health professions, including pharmacy.

The Pharmacy Board of Australia sets the profession-specific practice standards, codes of conduct, and registration requirements for pharmacists, while AHPRA provides the shared administrative and regulatory operations across all health professions.

The National Law is the legislation (Health Practitioner Regulation National Law) that establishes the National Registration and Accreditation Scheme, giving AHPRA and the National Boards (including the Pharmacy Board) their legal authority.

This triggers a mandatory notification obligation — registered health practitioners must report to AHPRA reasonable belief of impairment, intoxication while practising, significant departure from accepted standards, or sexual misconduct by a colleague, to protect the public.

Provisional registration is the intern pathway status for pharmacists completing their supervised training period before full registration — they must practise under supervision and cannot yet practise independently as a fully registered pharmacist.

The CMI (Consumer Medicine Information) leaflet gives patient-friendly written information on a medicine's uses, dosing, precautions, and side effects, supplementing — not replacing — verbal pharmacist counselling.

MedsCheck is a community pharmacy medicine review service for patients with chronic conditions or multiple medicines, helping identify problems like interactions, adherence issues, or duplicate therapy directly within the pharmacy.

An HMR (Home Medicines Review) is GP-referred and typically conducted by an accredited pharmacist in the patient's home, focused on complex or high-risk medicine regimens — unlike MedsCheck, which is pharmacist-initiated within the pharmacy.

A dose administration aid (DAA, e.g., Webster pack) organises doses by day and time to support adherence. A key limitation is that not all medicines are suitable for repacking (e.g., those affected by light, moisture, or requiring specific storage).

Reduced eGFR/creatinine clearance slows renal drug and metabolite elimination, raising the risk of accumulation and toxicity — doses of renally cleared drugs must be reduced or dosing intervals extended based on the patient's renal function.

Opioid substitution therapy uses long-acting opioid agonists — methadone (full agonist) or buprenorphine (partial agonist) — to stabilise patients with opioid dependence, reducing withdrawal, cravings, and harms associated with illicit opioid use.

Anticholinergics and sedatives are flagged as high-risk in older patients because they increase confusion, falls risk, and injury — a key focus of medication reviews and deprescribing conversations in this population.