The drug atlas
Ophthalmology/Carbonic anhydrase inhibitor (glaucoma)
Carbonic anhydrase inhibitors
also: dorzolamide · brinzolamide · acetazolamide · CAI
Overview
Reduce aqueous production — topical (dorzolamide) for chronic glaucoma, systemic (acetazolamide) for acute angle-closure and other uses.
Mechanism
Inhibit carbonic anhydrase in the ciliary body → ↓bicarbonate → REDUCE aqueous humour production → lower IOP. Acetazolamide is a sulfonamide.
Indications
- Open-angle glaucoma (topical add-on)
- Acute angle-closure glaucoma (IV/oral acetazolamide)
- Also: idiopathic intracranial hypertension, altitude sickness
The agents
Dorzolamide / brinzolamidetopical
Chronic glaucoma add-on.
Acetazolamidesystemic (oral/IV)
Acute angle-closure emergency; IIH; metabolic acidosis/hypokalaemia/paraesthesia.
Adverse effects
Systemic acetazolamide: paraesthesia, metabolic acidosis, hypokalaemia, renal stonescommon
Sulfonamide hypersensitivity (Stevens-Johnson)serious
Topical: ocular stinging, bitter tastecommon
Cautions & contraindications
Sulfonamide allergyall
Severe renal/hepatic impairment, hypokalaemiarenal
Interactions
- Other drugs causing hypokalaemia/acidosis
Monitoring & kinetics
IOP; U&E for systemic acetazolamide
Topical (dorzolamide) or systemic (acetazolamide). Acetazolamide is the acute-AACG production-reducer.
Source: NICE NG81 — Glaucoma · BNF — Carbonic anhydrase inhibitors