|Year : 1981 | Volume
| Issue : 3 | Page : 251-252
Penetration of doxycycline in aqueous humour
OP Kulshrestha, Kurian, HHR Keshwan
Dept. of Ophthalmology, S.M.S. Medical College, Jaipur, India
O P Kulshrestha
Dept. of Ophthalmology, S.M.S. Medical College, Jaipur
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kulshrestha O P, Kurian, Keshwan H. Penetration of doxycycline in aqueous humour. Indian J Ophthalmol 1981;29:251-2
Intraocular penetration of antibiotics are generally unsatisfactory and is not uniform. Therefore selection of an antibiotic for prophylaxis or treatment of intraocular infection should be on the basis of its intraocular penetration. The ocular penetration of Doxycycline has been studied by estimating its concentration in aqueous humous after oral administration.
| Materials and methods|| |
Thirty patients undergoing cataract surgery, having no systemic and ocular abnormality other than senile cataract were choosen for this study. The subjects were divided into three groups of 10 patients each. After a single oral dose of 200 mg. of Doxycycline the serum and aqueos samples were collected in Group-I between 2 to 4 hours, 12 hours later in Group-II and 24 hours after in GroupIII.
0.2 ml. of aqueous humour was taken out of the eye with a tuberculin syringe. Samples of blood (5.0 cc) were taken out simultaneously. Doxycycline was estimated both in the serum and aqueous humour by the fluorometric method.
| Observations|| |
The mean serum levels of Doxycycline in group I, II and III were 6.82, 4.06 and 2.34 microgram per ml. respectively. The mean aqueous concentrations in these groups were 0.65, 0.71 and 0.24 microgram per ml. respectively. The percentage penetration were 10.7%, 18.6% and 11.73% respectively which was fairly comparable.
But the percentage of penetration of the drug into the aqueous as compared to serum level remained more or less the same in the samples of the three groups.
| Discussion|| |
Considering 0.5-1.5 micrograms per ml. of Doxycycline in vivo to be therapeutically adequate, 7 out of 10 achieved this concentration in the aqueous in 2-4 hours and 9 out of 10 did so after 12 hours of drug administration. However, the concentration on aqueous had fallen below the effective concentration in all but one case (average 0.24 microgram per ml.).
In this study it is seen that therapeutic concentration of Doxycycline in aqueous is achieved after 2-4 hours and maintained even upto 12 hours of administration. But after 24 hours therapeutic concentration of the drug is maintained only in serum but not in aqueous. The average is now only 0.24 microgram/ml. According to the recommended dosage schedule the next dose of 100 mg. is to be given at the end of 24 hours of the first doze, which would further boost up the level of Doxycycline in the aqueous and serum to effective therapeutic concentration.
| Summary and conclusion|| |
The serum and aqueous humour penetration of Doxycycline after oral administration were studied in thirty human subjects. Therapeutic concentration of this drug was achieved in aqueous at the end of 2-4 hours and maintained at 12 hours but not at the end of 24 hours even though the therapeutic concentration of the drug in serum was maintained even at the end of 24 hours.
| References|| |
Goodman, L.S. and Gilman A., 1978., Pharmacological basis of therapeutics. 5tL ed. P. 1183.