are steroids P-gp inhibitors?!
Question: Are steroids P-gp inhibitors?
Answers:
::edit:::
Sorry Frank, i prior assumed you meant a sex hormone steroid.
If you go to Pubmed and type prednisone p-glyoprotein and run through the abstracts you can get the gist of how complex the scenario can be:
http://www.ncbi.nlm.nih.gov/pubmed
Glucocorticoids (e.g. prednisone being a synthetic one) are substrates for P-gp (conclusion of several studies). And generally they may increase its expression, and appear to be transported by P-gp (as a substrate). And generally, a poor response to glucocorticoids has been related, in part, to the overexpression of P-gp...[e.g. read Dilger K, Schwab M, Fromm MF..."Identification of budesonide and prednisone as substrates of the intestinal drug efflux pump P-glycoprotein.", Inflamm Bowel Dis. 2004 Sep;10(5):578-83.
It gets complicated however. For instance: P-gp expession might be reduced in inflamed tissue of patients with ulcerative colitis but not in non-inflamed tissue of the same relative to healthy controls (Gutmann H et al 2008). And in T and NK cells of patients with idiopathic thrombocytopenic purpura, prednisone did not modify he expression and function of P-gp (López-Karpovitch X et al 2008). etc..etc... You will need to read around many papers to get the gist. Thus it is not so cut and dry. Drugs used previously and currently, dietary factors (e.g grapefruit juice and certain herbal extracts), one's current state of health, and many more factors may confound the situation. Plus different cells/tissues may show a different response depending on your health status.
Don't ever stop or change medicines without your doctor's approval and supervision. That could be dangerous to do so. If you are concerned about how your body reacts to prednisone talk to your doctor. You should always consult with your doctor if you have any specific concerns. Your doctor might have knowledge and/or interest in multidrug resistance mechanisms (e.g. MDR1/P-gp) or if not he/she might be able to point you in the direction of another doctor who does...i.e. another specialist.
Best wishes.