|Year : 1983 | Volume
| Issue : 5 | Page : 521-524
Effect of oral acetazolamide on human aqueous and serum electrolytes
RG Sharma, Jagdish Prasad, YC Mishra, SP Vyas
Department of Ophthalmology, S.M.S. Medical College & Hospital, Jaipur, India
S P Vyas
Lecturer in Ophthalmology, S.M.S. Medical College and Hospital, Jaipur
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sharma R G, Prasad J, Mishra Y C, Vyas S P. Effect of oral acetazolamide on human aqueous and serum electrolytes. Indian J Ophthalmol 1983;31:521-4
|How to cite this URL:|
Sharma R G, Prasad J, Mishra Y C, Vyas S P. Effect of oral acetazolamide on human aqueous and serum electrolytes. Indian J Ophthalmol [serial online] 1983 [cited 2019 Aug 24];31:521-4. Available from: http://www.ijo.in/text.asp?1983/31/5/521/29535
The credit of producing a hypertonic fluid (aqueous) in anterior and posterior chambers of the eye goes to the complex behavior pattern of ciliary epithelium, a phenomenon, still not well understood.
The role of carbonic anhydrase inhibitors in controlling the intraocular pressure is well known but their effect on the ionic concentration of the aqueous and serum has not been extensively studied.
A study was therefore undertaken to evaluate the effects of acetazolamide administration with dose and time variation on the electrolytes in serum and aqueous in human subjects.
| Material and Methods|| |
Out of total 50 cases of mature senile cataracts, 5 cases served as control (where no Diamox was given) while rest of the 45 cases divided into group A & B for Diamox therapy with dose and time variation. The breakup of the cases is given below:
Group A. (with dose variation) schedule of doses of Diamox as given below
a) Tab. Diamox 250 mg. 1 H.S. I.C.M. - 5 cases
b) Tab. Diamox 250 mg. 1 T.D.S. - 5 cases
c) Tab. Diamox 250 mg. 1 H.S.x. 2 C.M. - 5 cases
d) Tab. Diamox 250 mg. 1 Q.I.D - 5 cases
e) Tab. Diamox 250 mg. 2 T.D.S. - 5 cases
Total - 25 cases
Aqueous and serum samples for electrolyte estimation were drawn after 2 to 4 hours of the last dose. Group B. (Time variation)
Aqueous and serum samples for electrolyte estimation in this group were drawn at intervals of 1, 2, 4 and 6 hours after the last dose of Diamox.
Tab. Diamox dose 2 H.S. and 2 C.M. was kept constant.
a) After 1 hour interval 5 cases
b) After 2 hours interval 5 cases
c) After 4 hours interval 5 cases
d) After 6 hours interval 5 cases
Total - 20 cases
| Observations|| |
[Table - 1][Table - 2][Table - 3].
| Discussion|| |
The present study revealed that the concentration of sodium ion in aqueous humour of mature senile cataracts varied from 136 m/ Eq lit to 146 m/Eq/lit. while the potassium concentration varied from 3-4 m Eq/ 5.0 m Eq/lit. with an average of 4.60 m Eq/lit.
The corresponding serum electrolyte analysis for Na revealed the range of 130 to 140 m Eq/ lit with a mean of 133.6 m Eq/lit. While the maximum K+ level recorded was 3.8 m Eq/lit and a minimum of 3.2 m Eq/lit. with an average of 3.4 m Eq/lit.
Cole  noticed the aqueous plasma ratio for sodium to be 0.965 in the aqueous of the anterior chamber and 0.972 in the aqueous of post chamber of rabbits. Kinsey  found Na+ to be 138 microgram/gm. H2O and 143 microgram/g H 2 O in the aqueous and plasma respectively. The concentration of the potassium had been 5.0 in the aqueous and 5.6 in the plasma.
The present work is in close conformity with the above observations. The steady state ratio for sodium has been found to be less than unity as was also observed by Kinsey  and Davson , The potassium concentration does not show much variation either in the present work or in the analysis of other workers.
Dose variation group
It was observed that with increasing doses there was steady fall in sodium and potassium concentrations both in aqueous and plasma. In the group where the Diamox was administered 250 mg, 1 H.S. and C.M., the average concentration of sodium and potassium electrolytes in the serum came down to 130 and 3.6 m Eq/lit. respectively as compared to the control values of 133.6 and 3.48 m Eq/lit. for Na -1- and K+ respectively.
A further fall in the concentration was observed when the doses were increased to 1 T.D.S. and 1 Q.I.D. However, no further appreciable fall was noticed when the Diamox was administered in the doses of 2 T.D.S.
An evaluation of corresponding values for the concentration of the electrolytes Sodium and Potassium in human aqueous indicates a definite downwards trend from 137.2 and 3.76 m Eq/lit. when Diamox was administered 1 H.S. and C.M. to 133.6 and 3.28 m Eq/ cases where Diamox was given 2 T.D.S.
Nakamura  reported a significant fall in sodium and potassium bicarbonate and chloride concentration after acetazolamide therapy and latter also noted that the maximum fall was usually present after one hour of the administration of the drug. Agarwal et al  observed a fall in the concentration of sodium, potassium bicarbonates and chlorides after administration of Diamox.
In the present work the concentration of Potassium was observed to have decreased from 3.76 m Eq/lit. and 3.16 m Eq/ aqueous and serum respectively to 3.28 and 3.12 m Eq/ lit. Havener  stated that the acetazolamide causes depletion of sodium and potassium in serum and aqueous 30% Kawabe  studying the effects of Diamox failed to record any change in electrolyte pattern.
The present work demonstrates a definite disturbance of electrolyte balance towards the lower side of the normal after administration of varying doses of Diamox. No significant fall was observed when the dosage was increased to 2 T.D.S. This is in close correlation with the observations of Havener  who observed that in human beings and rabbits tonographic studies indicate 50-60% inhibition of aqueous flow by acetazolamide and that no further increase in the secretion occurred even with a ten fold increase in the acetazolamide dosage. Becker" reported 61% suppression of aqueous secretion in normal and glaucomatous patients on an average with acetazolamide therapy.
Group B. (Time variation group)
A maximum fall in the concentration of Na+ and K+ in the serum and aqueous was observed in the first hour from 141.2 and 4.60 and 133.6 and 3.48 m Eq/lit to 134.0 sodium, 3.32 potassium and 128.4 sodium and 3.16 m Eq/lit potassium in the serum.
The samples of blood and aqueous analysed after 2 hours of Diamox administration revealed a very minimal further decrease with sodium and potassium. It appears therefore that the maximum effect of the drug appeared within first hour, as was observed by Nakamura in 1961. This remained effective for 4 hours but no further change was observed after 6 hours of administration.
Havener  observed the interesting fact that the acetazolamide rapidly reaches its maximum concentration in the blood within 1 to 2 hours and after that maintain for 4 to 6 hours.
The maximum reduction in the sodium and potassium ions in the aqueous and blood occurs with optimum dose of 2 H.S. and 2 C.M. and with a time variation keeping the dose constant the maximum reduction occurred within 1 to 2 hour time interval after last dose.
| Conclusion|| |
It can be safely assumed that the maximum efficacy is obtained with the dose of 2 H.S. and 2 C.M. within two hours of the last dose in reducing the intra ocular pressure.
| References|| |
Cole, D.H., Brit. J. Ophth., 43, 268, 1959.
Kinsey, V., Arch. Ophth., 50, 401, 1953.
Davson, H., J. Physiol., 129, 111, 1955.
Nakamura, B., Arch. Ophth., 134, 197, 1939.
Agarwal, L.P., Dayal, Y., and Agarwal, P.K., Orient. Arch. Ophth., 1, 248. 1963.
Havener, W.H., Ocular Pharmacology, C.V., Mosby Co. p. 466, 1974.
Kawabe, K., Acta. Soc. Ophth., Jap. 79, 674, 1975.
Becker, B., Amer. J. Ophth., 37,13, 1954.
[Table - 1], [Table - 2], [Table - 3]