As much as I'd like too I don't really want to try to explain this one to my doc. Anyway, I thought aromasin had a very short half-life? like 24-27 hours?
If you need a doc for the tests PM me and I can probably get you a HRT doc that would have zero problems setting things up for you.
Yes, about 1/2 the drug is no longer active around 24 hours.
Pharmacokinetics:
Absorption: Following oral administration, AROMASIN is rapidly absorbed. Animal data suggest that the oral bioavailability could be incomplete due to first-pass metabolism. At a single dose of 25 mg given after a meal, average peak plasma levels of 18 ng/mL are achieved within 2 hours post-dosing. Food was shown to enhance absorption, resulting in plasma levels 40% higher than those observed in subjects under fasting conditions.
Distribution: After the peak, plasma levels of AROMASIN decline in a polyexponential manner with a terminal half-life of approximately 24 hours. AROMASIN is extensively distributed into tissues as reflected by a high volume of distribution. The plasma protein binding of AROMASIN is approximately 90% and the fraction bound is independent from the total concentration. The distribution of the drug and/or its metabolites into blood cells is negligible.
Metabolism and excretion: No significant deviations from dose-proportional pharmacokinetics were observed in healthy volunteers up to a 50 mg oral dose. Following repeated daily administration of 25 mg, plasma concentrations of the unchanged drug were of a similar order to those measured after single dosing. Following oral administration of a single dose radiolabelled AROMASIN, the elimination of drug-related products was shown to be essentially complete within 1 week, with approximately equal proportions of the dose eliminated in urine and faeces. The amount of drug excreted unchanged in urine is less than 1% of the dose. The clearance of AROMASIN is high, mainly due to metabolism. The biotransformation proceeds through oxidation of the methylene group at position 6 via the CYP 3A4 isoenzyme and/or reduction of 17-keto group by aldoketoreductases. Subsequently, many secondary metabolites are formed, each accounting for a limited amount of the drug. The metabolites are either inactive or less active than the parent drug in inhibiting aromatase.
Special populations:
Age: No significant correlation between the systemic exposure of AROMASIN and the age of subjects has been observed.
Renal insufficiency: AROMASIN pharmacokinetics have been investigated in subjects with severe renal insufficiency (CL
CR <30 mL/min). In these subjects the systemic exposure of AROMASIN after a single dose was found to be approximately double that of healthy volunteers.
Hepatic insufficiency: AROMASIN pharmacokinetics have been investigated in subjects with moderate and severe hepatic insufficiency. The systemic exposure to AROMASIN was 2-3 times higher than in healthy volunteers.