Diamox (Acetazolamide) Formulations
No, Diamox (acetazolamide) does not come as eye drops—it is only available as oral tablets or sustained-release capsules for glaucoma treatment. 1
Available Formulations
Acetazolamide is classified as an oral carbonic anhydrase inhibitor used for decreasing aqueous humor production in glaucoma management. 1
The medication comes in:
- 250 mg tablets taken four times daily 2
- 500 mg sustained-release capsules taken once or twice daily 2
Why Not Eye Drops?
The development of topical acetazolamide formulations has been limited by significant pharmaceutical barriers:
- Poor ocular bioavailability due to inadequate corneal penetration 3
- Poor biphasic solubility that prevents effective eye drop formulation 3
- While experimental complexes (ACZ:HP-beta-CD:TEA) have been studied to improve topical delivery, these remain investigational and are not commercially available 3
Topical Alternatives Available
If topical carbonic anhydrase inhibition is desired, FDA-approved topical formulations include:
- Dorzolamide (topical carbonic anhydrase inhibitor) 1
- Brinzolamide (topical carbonic anhydrase inhibitor) 1
These topical agents provide 15-20% IOP reduction compared to acetazolamide's 20-30% reduction, but avoid systemic side effects. 1
Clinical Efficacy Comparison
Research demonstrates that oral acetazolamide remains more effective than topical alternatives:
- In pediatric glaucoma patients, switching from oral acetazolamide to topical dorzolamide resulted in a mean IOP increase of 3.7 mm Hg (20.2% increase), with all 11 eyes showing worse control on the topical agent 4
- Oral acetazolamide achieved 35.7% IOP reduction versus 27.4% with topical dorzolamide 4
Important Clinical Caveat
When prescribing oral acetazolamide, be aware of significant systemic side effects including Stevens-Johnson syndrome, malaise, depression, electrolyte imbalances, renal calculi, and blood dyscrasias. 1 The medication is contraindicated in sulfonamide allergy, kidney stones, aplastic anemia, and sickle cell disease. 1