Carbonic anhydrase inhibitor + beta-blocker (combination eye drops)
Dorzolamide with timolol
Brand names: Cosopt
Adult dose
Dose: 1 drop into affected eye(s) BD
Route: Ophthalmic
Frequency: BD
Clinical pearls
- NICE NG81 glaucoma: combination eye drops when monotherapy inadequate; reduces drop burden and improves adherence
- RCOphth glaucoma pathway
- Punctal occlusion 1 minute after instillation reduces systemic absorption
Contraindications
- Severe asthma
- Severe COPD
- Bradyarrhythmia / heart block
- Heart failure (timolol)
- Severe renal impairment (dorzolamide)
- Sulfonamide hypersensitivity
- Hypersensitivity
Side effects
- Ocular: burning, taste disturbance, blurred vision, conjunctival injection
- Systemic: bronchospasm, bradycardia, depression, hypoglycaemia masking, fatigue
Interactions
- Systemic beta-blockers (additive)
- Verapamil/diltiazem (bradycardia)
- Insulin/oral hypoglycaemics (hypoglycaemia mask)
- Other oral CAIs
Monitoring
- IOP
- Visual fields
- HR/BP if cardiovascular risk
- Asthma symptoms
Reference: BNF; NICE NG81; RCOphth; https://bnf.nice.org.uk/drugs/dorzolamide-with-timolol/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
- SMART Risk Score for Recurrent CVD · Cardiovascular Risk
- MAGGIC Heart Failure Risk Score · Heart Failure
- Long QT Syndrome (Schwartz Score) · Channelopathy / Sudden Cardiac Death
- PCSK9 Inhibitor Eligibility Assessment · Lipid Management
- C-Peptide to Glucose Ratio · Diabetes Classification
- Immune-Related Adverse Events (irAE) -- GI Toxicity Colitis Grading · Oncology-Related GI
Pathways
- Acute Red Eye / Vision Loss Screen · RCOphth 2020; NICE CKS
- Idiopathic Intracranial Hypertension · ABN; consensus 2018
- Acute Red Eye Assessment · RCOphth / AAO
- Acute Angle Closure Glaucoma · RCOphth / EGS Guidelines
- Retinal Detachment · RCOphth Guidelines / EURETINA
- Diabetic Retinopathy — Screening and Management · NICE NG28 2016 / NHS DES Programme