Therapeutic window
Encyclopedia
The Therapeutic window of a drug is the range of drug
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...

 dosage
Dose (biochemistry)
A dose is a quantity of something that may impact an organism biologically; the greater the quantity, the larger the dose. In nutrition, the term is usually applied to how much of a specific nutrient is in a person's diet or in a particular food, meal, or dietary supplement...

s which can treat disease effectively while staying within the safety range. In other words, it is the dosages of a medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

 between the amount that gives an effect (effective dose
Effective dose (pharmacology)
An effective dose in pharmacology is the dose or amount of drug that produces a therapeutic response or desired effect in some fraction of the subjects taking it....

) and the amount that gives more adverse effects than desired effects. For instance, medication with a small pharmaceutical window such as Tegretol
Carbamazepine
Carbamazepine is an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder, as well as trigeminal neuralgia...

 must be administered with care and control, e.g. by frequently measuring blood concentration of the drug, since it easily gives adverse effects such as agranulocytosis
Agranulocytosis
Granulopenia, also known as Agranulosis or Agranulocytosis, is an acute condition involving a severe and dangerous leukopenia , most commonly of neutrophils causing a neutropenia in the circulating blood. It represents a severe lack of one major class of infection-fighting white blood cells...

.

More specifically, it is the range between the ED50
Effective dose (pharmacology)
An effective dose in pharmacology is the dose or amount of drug that produces a therapeutic response or desired effect in some fraction of the subjects taking it....

 and the starting point of TD50 curve
Curve
In mathematics, a curve is, generally speaking, an object similar to a line but which is not required to be straight...

. It is believed that this index can help to avoid most of the potential side effect
Adverse effect
In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...

s. It is worth noting that the window can vary by situation. In some cases, the therapeutic window can even be completely "closed", meaning that the adverse effects exceed the desired effects at all doses capable of providing the desired effect. This is the (politicized) assertion made by governments that prohibit certain drugs: that any dose, they do more harm than good.

This index is believed to be more reliable than either the therapeutic index
Therapeutic index
The therapeutic index is a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes death or toxicity ....

 or the protective index
Protective index
The protective index is a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes toxicity. Quantitatively, it is the ratio given by the toxic dose divided by the therapeutic dose. A protective index is the toxic dose of a drug for 50% of the...

, since this index considers the biological variation among individuals to a larger extent. The downside, however, is that it (like the protective index) also introduces an element of subjectivity.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK