A compound with a narrow therapeutic index ( close to one ) exerts its desired effect at a dose close to its toxic dose.
32.
Since warfarin is an anticoagulant with a low therapeutic index, warfarin may cause bleeding if the correct degree of pharmacologic effect is not maintained.
33.
A compound with a wide therapeutic index ( greater than five ) exerts its desired effect at a dose substantially below its toxic dose.
34.
*The "'therapeutic index "'of a medication is a comparison of the amount that causes the therapeutic effect to the amount that causes toxic effects.
35.
For example, whereas penicillin has a high therapeutic index as it does not generally affect human cells, this is not so for many antibiotics.
36.
The margin of safety is relatively small ( narrow therapeutic index ); too little may not work at all, too much may cause side effects.
37.
It has been shown that the dextrorotatory form is particularly active and has a much higher therapeutic index than some other anti-inflammatories, including indomethacin and diclofenac.
38.
The use of aminopterin in cancer treatment was supplanted in the 1950s by methotrexate due to the latter's better therapeutic index in a rodent tumor model.
39.
The benzodiazepines gained popularity among medical professionals as an improvement over barbiturates, which have a comparatively narrow therapeutic index, and are far more sedative at therapeutic doses.
40.
LMWHs and fondaparinux target antifactor Xa activity rather than antithrombin activity, with the aim of facilitating a more subtle regulation of coagulation and an improved therapeutic index.
