Okuzeka
Pharmacy & Pharmacology vocabulary · Pharmacodynamics and Drug Action

Therapeutic index

Meaning in pharmacy & pharmacology, with examples

nounCommon term

In pharmacy & pharmacology, therapeutic index means: A measure of a drug's safety that compares the dose that causes harm with the dose that gives the wanted effect; a narrow index means these doses are close together.

In Turkish: terapötik indeks, tedavi indeksi

How it is used

Mostly heard in 'narrow therapeutic index' (NTI), for drugs such as warfarin, digoxin, lithium and phenytoin. These drugs often need blood level monitoring, and small changes in dose, brand or interactions can matter. 'Therapeutic window' and 'therapeutic range' describe the safe and effective concentration range.

Example sentences

  1. Lithium has a narrow therapeutic index, so regular blood tests are essential.

  2. Drugs with a narrow therapeutic index need extra care when switching brands.

Common collocations

  • narrow therapeutic index
  • wide therapeutic index
  • therapeutic window
  • therapeutic range
  • toxicityThe harmful effects a drug or chemical has on the body, especially at high doses or blood levels, or the degree to which a substance is poisonous.
  • plasma concentrationThe amount of a drug in a given volume of blood plasma at a particular time, used to describe how a drug behaves and to check that levels are safe.
  • potencyThe amount of a drug needed to produce a given effect; a highly potent drug works at a very small dose.
  • efficacyThe ability of a drug to produce the wanted effect; in pharmacology, the maximum effect a drug can produce, however high the dose.

More terms: Pharmacodynamics and Drug Action

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