LABORATORY AND CLINICAL STUDIES ON DOXYCYCLINE IN OTO-RHINO-LARYNGOLOGIC FIE L D
1969 Volume 17 Issue 2 Pages 414-420
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1969 Volume 17 Issue 2 Pages 414-420
From the laboratory and clinical studies on doxycycline, a new antibiotic belonging to the series of tetracyclines, the following results were obtained.
1. Single oral doses of 200 mg of the drug produced the serum peak at 7 hours. Its avearge level was 2. 5 mcgml in 3 adults.
Serum concentration fell then gradually, but it was still 0. 9 mcg/ml at 24 hours after administration of the drug.
2. Tissue concentrations of doxycycline in tonsils were measured. An average tissue level of 0. 7 mcg/g was obtained at 4 hours after oral administration of 200 mg.
3. The sensitivity of 37 strains, isolated from the pathological materials in our clinic, to doxycycline was measured by plate dilution method. Seventy-one per cent of gram positive cocci including staphylococci, streptococci and diplococci, were inhibited to grow by the presence of 0. 78 mcg/ml or less. Gram negative bacilli were highly resistant to this antibiotic except a strain of E. coil which 420 CHEMOTHERAPY MAR. 1969 was sensitive to 3. 12 mcgirni. Doxycycline was found to have almost complete cross resistance with tetracycline in 24 strains of coagulase-positive Staphylococcus aureus, but doxycycline was more active against these strains than tetracycline.
4. Doxycycline was clini cally used to 22 cases of ear, nose and throat infections and it was effective in 77. 3% of them.
5. No side effe ct was observed in all cases.
