CLINICAL AND EXPERIMENTAL STUDIES ON DOXYCYCLINE

Abstract

We have recently obtained the result described below through the clinical and experimental studies on doxycycline.
1) The minimal inhibitory concentration in doxycycline was measured by plate agar dilution method. Doxycycline inhibited by <0.19-0.39 mcg/ml against coagulase-positive Staphylococcus aur e us 40 strains. Doxycycline showed higher sensitivity than other antibiotics.
2) The level of blood concentration in doxycycline was determined by the average of 3 cases for adult. The maximal level reached 3. 2 mcg/ml in 4 hours after per os, as the result measured by single oral administration of 200 mg. And blood level still maintained 0. 82 mcg/ml in 24 hours after per o s.
3) The urinary excretion was determined by the average of 3 cases for adult. The urinary total excretion showed 17. 9 mg within 12 hours after oral administration of 200 mg. Urinary recovery showe d a low level such as 4. 2∼11. 9 per cent of the total dosage.
4) The pus concentration could not be measured at 6 hours after oral administration of 200mg in the operation of maxillary sinusitis.
5) Rat tissue concentration showed that kidney indicated the highest activity of doxycycline and other tissues were in the following order; liver, spleen, lung and heart.
6) By oral administration (100200 mg) or local application (5 ragiml solution) on 34 cases of infections in otorhinolaryngologic field, doxycycline produced a good result of 73. 5% (25 cases).
7) Side effects: Oral administration of doxycycline occurred the side effects to 3 cases; nausea and vomiting, for which its administration was terminated. Yet on the local administration no such s i de effects were observed. The comparative examinations of liver, kidney and electrolyte, audiogra m before and after administration showed no significant disturbances.