ステロイド点耳後の体内動態について

抄録

Betamethasone (BM) solution (0.1%) was topically administered at 2:00p.m. to the ear of seventeen preoperative patients, and then the serum concentrations of both BM and hydrocortisone, product of the adrenal gland, were measured at 3:00p.m. and 4:00p.m.
The tested ears showed various kinds of pathology, such as a large central perforation, attic perforation, eustachian tube malfunction. The of preoperative diagnoses were as follows: 2 otosclerosis, 1 sudden deafness, 1 traumatic dislocation of the ossicles, and 13 chronic otitis media.
The purpose of this study was to ascertain whether or not the ear-drop steroid suppressed the adrenal function, and to speculate the total steroid dose that might be absorbed from the external canal skin, tympanic membrane, middle ear mucous membrane and tubal mecous membrane.
The results were summarized as follows:
1) Three drops of 0.1% betamethasone to the ear may suppressed the adrenal function in patients with the perforated tympanic membrane.
2) The rate of absorption of ear-drop steroid was speculated. If the tympanic membrane was perforated and tubal function was good, the rate was calculated to be 100%, similar to that of oral administration, and if not, the rate might be less than 25%.