Where does this line of thinking come from? Why would a SERM, which only attaches to estrogen receptors, effect the inhibition of the aromatase enzyme to convert T->E? I don't think this is a true statement, and think running a SERM with an AI is a pretty good idea if one is sensitive to SERM side effects caused by the build up of E2 in the body's system, which attaches to receptors not occupied by the SERM.
It's a fairly well known, well documented drug interaction. It's also in the stickies, iirc.
And you're right, running an AI with a SERM is a good idea. But not Adex. Aromisin shows no such interaction with Nolva.
GENERALLY AVOID: Coadministration with tamoxifen may decrease the plasma concentrations of anastrozole. The mechanism of interaction has not been described. In one clinical trial, coadministration of tamoxifen (20 mg/day) and anastrozole (1 mg/day) in breast cancer patients resulted in decreased anastrozole plasma concentration by 27% compared to administration of anastrozole alone. In addition, at a median follow-up of 33 months, the combination did not demonstrate any efficacy benefit over tamoxifen therapy alone in all patients as well as in the hormone receptor-positive subpopulation, and this treatment arm was discontinued from the trial. The pharmacokinetics of tamoxifen and its pharmacologically active N-desmethyl metabolite were not affected.
MedicinesComplete: Baxter K (ed). Tamoxifen + Aromatase inhibitors: Stockleys Drug Interactions. RPS Publishing, London, UK,
MedicinesComplete: McEvoy GK (ed). Anastrozole: American Hospital Formulary Service Drug Information. RPS Publishing, London, UK,
Dowsett M, Cuzick J, Howell A et al: Pharmacokinetics of anastrozole and tamoxifen alone, and in combination, during adjuvant endocrine therapy for early breast cancer in postmenopausal women: a sub-protocol of the 'Arimidex and tamoxifen alone or in combination' (ATAC) trial.. Br J Cancer (2001) 85 (3/Aug 3): 317-24