Principles of Pharmacology Flashcards

Flashcards on principles of pharmacology, including concentration response curves, types of experiments (in vitro, in vivo, ex vivo), EC50, potency, and therapeutic index.

Concentration-response relationship

Drug effects are quantified by studying the relationship between drug concentration (or dose) and the response produced by the drug.

Experiments in vitro

Drug effects are studied on a piece of tissue dissected from an animal (or human) and kept alive outside the body.

Experiments in vivo

Drug effects are studied in the living animal (or human).

Experiments ex vivo

A tissue or organ is removed from an animal that has been treated with a drug, and the effects the drug has had on organ function are tested in vitro.

Molar Concentration

For experiments in vitro, concentrations are expressed in Moles per litre i.e. Molar (M). A 1 Molar solution contains 1 Mole of a drug dissolved in 1 litre of solvent

Doses in vivo

Drug doses in this type of experiment are expressed as weight of drug per weight of animal e.g. 1 mg per kg (1 mgkg- 1)

Emax

Indicates the maximum response (effect) the drug can produce, i.e. the top of the concentration-response curve

EC50

The Molar concentration of a drug that produces 50% of the maximum response for that drug

Potency

A commonly used term to describe the concentration at which a drug is effective. A potent drug is effective in very small amounts

Potency Ratio (M)

Comparing EC50 values for two drugs with the same action allows us to calculate their relative potencies, described by the potency ratio (M). M = EC50(test)/EC50(standard)

Therapeutic Index

The ratio between the toxic dose of a drug and the dose producing the desired therapeutic effect