ADME is short for absorption, distribution, metabolization/metabolism and excretion and describes the effectiveness of a pharmaceutical compound within an organism. The four criteria are all critical with respect to the success of the compound as a drug:

absorption 

before a compound can become biologically active, it has to be taken in to the blood stream - usually via mucous surfaces like the digestive tract (intestinal absorption). Uptake into the target organs or cells needs to be ensured, too. This can be a serious problem at some natural barriers like the blood-brain barrier.

distribution 

care has to be taken that the compound is carried to its effector site, most often through the blood stream

metabolization 

compounds need to be chemically broken down, once they have worked their effect or otherwise they will accumulate in the tissue and keep disturbing the natural processes. In some cases chemical modifications taking place within the organism are the pre-requisite for them to become active in the first place.

excretion 

the metabolized compounds have to be excreted, again in order not to become accumulated in some organ or tissue where they could seriously affect the metabolism.

Sometimes, the potential or real toxicity of the compound is taken into account (ADME-Tox). When the liberation of the substance (from protective coating etc.) is considered, we speak of LADME.

Computational chemists try to predict the ADME-Tox qualities of compounds through methods like QSPR/QSAR.

See also

• Cheminformatics, combinatorial chemistry, Pharmacology, solubility, serum, Lipinski's Rule of 5, bioavailability