TT Pharmacy Registration Exam key terms

The proportion of an administered dose of a drug that reaches the systemic circulation unchanged, together with the rate at which it arrives. Intravenous dosing is taken as complete, so oral bioavailability is usually below one.

Breakdown of an orally swallowed drug in gut wall or liver before it reaches the general circulation, which lowers the amount available to act. Drugs with heavy first-pass loss often need higher oral doses or alternative routes.

The demonstration that two products of the same drug release the active ingredient into the body at rates and extents that are not meaningfully different. Regulators accept such products as therapeutically interchangeable with the reference product.

A formulation engineered to liberate drug gradually over hours rather than at once, smoothing plasma peaks and troughs and often reducing dose frequency. Crushing or chewing such products can cause dose dumping and toxicity.

Any inactive ingredient added to a medicine to give it bulk, stability, flow, taste, or controlled release. Excipients can still cause harm, for example lactose in lactose-intolerant patients or dyes in allergic individuals.

A preparation free of viable microorganisms, required for injections, eye drops, and anything entering normally sterile body sites. Its manufacture demands validated aseptic technique or terminal sterilisation plus environmental monitoring.

The set of practices, including hand hygiene, sterile gloves, disinfection, and working in a controlled airflow, that keeps microorganisms out of a preparation. It underpins every product that cannot be terminally sterilised.

A drug that binds a receptor and switches it on, mimicking the body's own signalling molecule. Full agonists produce maximal response, while partial agonists produce a lesser response even at full occupancy.

A drug that occupies a receptor without activating it, blocking the natural messenger. Competitive antagonists can be overcome by more agonist, whereas non-competitive antagonists cannot.

A ratio comparing the dose producing toxicity with the dose producing the desired effect. A narrow index means small dose changes can cause harm, so such drugs need careful dosing and often plasma monitoring.

Measuring plasma concentrations of drugs with narrow therapeutic windows, such as digoxin, lithium, or phenytoin, to individualise dosing. Sampling time matters because the result is interpreted against a reference range at a defined point after the dose.

The study of what the body does to a drug, summarised as absorption, distribution, metabolism, and excretion. These processes determine how quickly a drug acts and how long its effect lasts.

A harmful or unintended response to a medicine used at normal doses. Reactions are classified by mechanism and predictability, and serious ones must be reported to the national pharmacovigilance authority.

The science of detecting, assessing, and preventing adverse effects of medicines once they are in real-world use. Spontaneous reporting schemes and signal review are its core activities.

An inactive chemical form of a drug that the body converts into the active molecule, usually to improve absorption or targeting. Conversion may depend on liver enzymes, so interacting drugs can change its effect.

The link between specific features of a molecule's structure and its biological effect. Medicinal chemists use it to add, remove, or swap chemical groups and thereby tune potency, selectivity, and side effects.

The property of a molecule that exists as non-superimposable mirror-image forms called enantiomers. Enantiomers can differ in potency or safety, so some drugs are now marketed as a single pure enantiomer.

The responsible provision of drug therapy to achieve definite outcomes that improve a patient's quality of life. It moves the pharmacist from product supply toward shared responsibility for therapeutic results.

A structured process of comparing a patient's full medicine list across care transitions to catch omissions, duplications, and errors. It is performed on admission, transfer, and discharge and is a recognised patient-safety priority.

The extent to which a person takes medicines as agreed with their prescriber, covering timing, dose, and persistence. Non-adherence may be intentional or unintentional and is assessed without blaming the patient.

A consultation model in which prescriber and patient agree on a treatment plan after sharing information and respecting the patient's views. It differs from simple obedience to instructions and supports shared decision-making.

A patient's voluntary agreement to a treatment or procedure after receiving understandable information about benefits, risks, and alternatives. It must be obtained from someone with capacity, or from a lawful representative.

The professional duty to keep patient information private and share it only with those who need it for care or as the law permits. Breach can be both an ethical failing and a regulatory offence.

Cover that protects a pharmacist against claims arising from professional practice, such as dispensing errors or advice that causes harm. Many registration bodies require it as a condition of practice.

Any preventable event that may cause or lead to inappropriate medicine use or patient harm, at any stage from prescribing to administration. Errors are usually system failures rather than individual carelessness.

A mistake made during the supply of a medicine, such as the wrong drug, strength, form, or label, or wrong directions. Reporting and root-cause review are used to prevent recurrence.

The extemporaneous preparation of a medicine to meet an individual patient's need when no suitable licensed product exists. It requires documented formulae, verified calculations, and an appropriate risk assessment.

An arithmetic method for finding the ratio in which two preparations of different strengths must be mixed to give a required intermediate strength. It is a standard technique in compounding calculations.

The mass of a drug that occupies the same volume as one unit of base in a suppository or similar mould. It is used to calculate how much base to subtract so the finished unit contains the correct dose.

A product containing the same active substance as an originator brand, marketed after patent expiry and shown to be bioequivalent. It is usually cheaper but must meet the same quality standards.

Supplying a different but equivalent medicine in place of the one prescribed. Rules differ between jurisdictions, and pharmacists must know when substitution is permitted, required, or forbidden.

The legal conditions under which a prescription may be dispensed, such as required content, prescriber authority, and time limits. A prescription failing these conditions should not be supplied.

A medicine subject to special legal controls because of abuse or dependence potential, covering storage, record-keeping, and supply. Requirements vary by schedule and jurisdiction and are strictly enforced.

A national spontaneous reporting scheme through which health professionals and patients flag suspected adverse drug reactions. Reports feed into signal detection even when causality is not yet proven.

A herbal preparation adjusted so that a defined marker compound or group falls within a stated range, improving consistency between batches. Standardisation does not by itself prove clinical effectiveness.

A change in a medicine's effect caused by a plant preparation, often through enzyme induction or inhibition. St John's wort, for example, can reduce concentrations of several prescribed drugs.

An inactive treatment given for its psychological effect or used as a control in trials. Comparing a drug with placebo helps show whether benefit exceeds expectation and natural recovery.

A study in which participants are allocated by chance to treatments so that groups are comparable. It is the strongest design for judging whether an intervention causes an effect.

Protecting people from infection by exposure to a vaccine that trains the immune system, or by transfer of antibodies. High population coverage reduces transmission and protects those who cannot be vaccinated.

Planned activity that helps people improve and protect their health, through education, supportive environments, and healthy public policy. It goes beyond giving information to address the causes of ill health.

Testing apparently healthy people to find disease or risk factors early, when treatment is more effective. A programme is worthwhile only if the condition is important, the test acceptable, and effective treatment available.

The application of economic analysis to medicines and pharmacy services, weighing costs against health outcomes. Common forms include cost-effectiveness, cost-utility, and cost-benefit analysis.

A single measure combining length of life with its quality, where one year in perfect health equals one. It allows comparison of very different treatments and is widely used in funding decisions.

The list of medicines approved for use within a health system or institution, with guidance on selection. Formularies support consistent, cost-effective prescribing and are maintained by a committee.

The rate at which stock is sold and replaced over a period, calculated by dividing cost of goods sold by average stock value. Low turnover ties up capital and raises the risk of expiry.