Estradiol Pellet
Status
FDA-approved. One oestradiol pellet product has held FDA approval for menopausal vasomotor symptoms and hypoestrogenism. Most pellets used in practice are compounded, which means they are not FDA-reviewed for potency, purity or release characteristics. The class boxed warning for oestrogen therapy applies.
What it is
An implanted estrogen pellet placed by a clinician every few months.
What published research measured
Crystalline oestradiol implanted subcutaneously for release over several months. The hormone's evidence base is as described for oestradiol generally; what is specific to this route is a pharmacokinetic pattern that has drawn published criticism. Pellets can produce supraphysiological serum concentrations, particularly after repeated implantation, and concentrations accumulate with successive insertions in a way that is difficult to predict. As with any implant, the dose cannot be withdrawn once placed. Tachyphylaxis — the return of symptoms at rising serum concentrations, prompting earlier reinsertion — is described in the literature on oestrogen pellets. Compounded pellet products are not standardized between preparers.
Source
Published pharmacokinetic criticism of oestradiol implant accumulation and tachyphylaxis
Sources
No linked primary source is on file for this entry yet.
Educational use only, never medical advice. No doses.