Aspirin
Severe
Database
Drug interaction classified as: distribution.
Source: DDInter
Drug reference
Dorzolamide
Topical carbonic anhydrase inhibitor (ophthalmic) · Antiglaucoma agent
Also known as Dorzolamide Hydrochloride, Trusopt
START
2% 1 drop TID (or BID with a beta-blocker / fixed combination)
TYPICAL MAX
1 drop TID (no added benefit beyond)
STOP IF
Sulfonamide hypersensitivity reaction, corneal decompensation/oedema
WATCH
IOP response, corneal status (low endothelial count), sulfonamide allergy history, dropper hygiene
CDSCO approvedSchedule HJan AushadhiATC S01EC03
KDIGO 2024 + manufacturer label
- ONSET
- 2h · IOP onset
- PEAK
- 2h · peak IOP reduction
- t½
- 4h · plasma (RBC-bound long; illustrative)
- DURATION
- 10h · effect (TID interval)
EXCRETION
Renal — unchanged drug + active metabolite
route + CYP
INTERACTIONS
7 major
SEVERE in our sources
PREGNANCY
Use only if clearly needed — limited data; minimal systemic exposure
FDA category + note
Top interactionssee all 8 →
- AspirinSevereDatabaseDDInter
- Bismuth SubsalicylateSevereDatabaseDDInter
- Choline SalicylateSevereDatabaseDDInter
- DiflunisalSevereDatabaseDDInter
Available in India
20 branded formulations. Look up specific brands in the Drugs workspace.
Jan Aushadhi — generic available at GoI pharmacies
Mechanism
Inhibits carbonic anhydrase II in ciliary processes, reducing bicarbonate and aqueous humour formation → lowered intraocular pressure; topical (minimal systemic exposure vs oral CAIs).
Indications
Elevated intraocular pressure in ocular hypertension or open-angle glaucomaAdjunct to beta-blockers/prostaglandin analogues (incl. fixed-combination with timolol)
Dosing
- Adult
- 2% solution: 1 drop in affected eye(s) three times daily (or twice daily when used with a beta-blocker/in fixed combination).
- Pediatric
- ≥2 years: 1 drop TID (per specialist).
- Renal adjustment
- Not recommended if CrCl <30 mL/min.
- Hepatic adjustment
- Not studied — use with caution.
- Geriatric
- No specific adjustment.
- Max dose
- 1 drop three times daily (no benefit beyond)
Pharmacokinetics
Onset
IOP reduction ~2 h
Peak effect
~2 h
Duration
8–12 h (TID dosing)
Half-life
Accumulates in RBC carbonic anhydrase (very long terminal); plasma low
Bioavailability
Topical ocular (low systemic)
Protein binding
~33%
Metabolism
Active metabolite N-desethyl (also CA inhibitor)
Excretion
Renal (unchanged drug + metabolite)
Contraindications
- Hypersensitivity to dorzolamide or sulfonamides
- Severe renal impairment (CrCl <30 — systemic CAI accumulation, not studied)
Side effects
Common
Ocular burning/stinging on instillationBitter taste after instillationSuperficial punctate keratitisConjunctival hyperaemia/blurred visionEyelid reactions
Serious
- Severe sulfonamide reactions (SJS/TEN, blood dyscrasias — rare, topical)
- Corneal oedema/decompensation (pre-existing low endothelial count)
- Bacterial keratitis (contaminated dropper)
Pregnancy & lactation
Pregnancy
Use only if clearly needed — limited data; minimal systemic exposure
Lactation
Topical, low systemic — considered low risk; caution
Drug interactions
Bismuth Subsalicylate
Severe
Database
Clinical effect not specified
Source: DDInter
Choline Salicylate
Severe
Database
Clinical effect not specified
Source: DDInter
Diflunisal
Severe
Database
Clinical effect not specified
Source: DDInter
Oral Carbonic Anhydrase Inhibitors
Severe
Database
Additive systemic CA inhibition/acidosis
Avoid concurrent use
Source: Kimi deep-research + Cla
Phenyl Salicylate
Severe
Database
Clinical effect not specified
Source: DDInter
Salsalate
Severe
Database
Clinical effect not specified
Source: DDInter
High Dose Salicylates
Moderate
Database
Potential acid-base/CAI interaction (systemic absorption)
Caution; monitor
Source: Kimi deep-research + Cla
4 additional low-confidence interactions hidden — those rows lack a documented mechanism or management plan in our sources.
Related guidelines
Other Topical carbonic anhydrase inhibitor (ophthalmic) drugs
Ask House about Dorzolamide
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Katzung, BNF·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19