Carbonic Anhydrase Inhibitors

Carbonic Anhydrase Inhibitors

1. Acetazolamide
2. Dorzolamide
3. Dichlorphenamide
4. Methazolamide

Mechanism Of Action :

Inhibition of carbonic anhydrase enzyme

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Inhibition of bicarbonate ion formation in aqueous

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Reduced Na²⁺ in ciliary body

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Reduced H₂O absorption

↓

Reduced aqueous formation

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Decreased IOP

Duration of Action : 6-8 hours

Frequency : QID

INDICATIONS :

1. Short term : all types of acute & chronic glaucoma
2. Long term : reserved for patients at high risk of visual loss, where all other treatment fails.
3. Prophylaxis : intra ocular surgery

SIDE EFFECTS :

1. Paresthesia of fingers, toes, hands, feet & around the mouth – hence it is ALWAYS PRESCRIBED with electrolyte rich items:
   • BANANA – contra indicated in diabetics
   • COCONUT WATER
   • SYRUP POT CHLOR (Potassium Chloride ) : if above two are not available.
2. Urinary frequency due to diuretic effect
3. Serum electrolyte imbalance :
   • Bicarbonate depletion : malaise, fatigue, loss of libido, anorexia & weight loss
   • K⁺ depletion : especially in those taking steroids too.
4. G.I.T. : abdominal discomfort, gastric irritation, nausea, metallic taste & diarrhea
5. Sulfonamide related side effects : S-J syndrome, renal calculi, blood dyscrasias, transient myopia, HT nephropathy, teratogenic.
   

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