This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== Systemic Alkalinisation ====== Alkalinisation may decrease the toxicity of [[:wikitox:2.1.11.9.2.1_tricyclic_antidepressants|tricyclic antidepressants]] through a number of mechanisms; for all of the mechanisms a change in ionisation status is important. In effect, a shift in pH towards the pKa (approximately 8.5) causes a decrease in ionised drug and an increase in un-ionised drug. * receptor binding in the sodium channel prefers ionised drug * drug lipid solubility is increased for the un-ionised drug. This allows drug to diffuse quickly back into the cell membrane partition, it may also increase redistribution into fat * the free fraction of TCA may be reduced by about 20% this is probably due to non-specific uptake into circulating lipids as the other carrier proteins (albumin and alpha glycoproteins) are normally saturated at toxic concentrations of TCA {{:wikitox:tcaph.jpg|tcaph.jpg}} CKG Edit