Schedule H

Ophthalmic (topical), Intracameral (intraoperative use only)

• Ophthalmic solution: 1.5%, 3%

• Intracameral solution: 0.01% (preservative-free, surgical use only)

INDICATIONS + DOSING — FOR CLINICIAN USE ONLY

Primary Indications (Approved / Standard in India)

1. Glaucoma (Open-angle and Angle-closure – Adjunctive Therapy)

Parameter Dosing

Starting dose 1 drop of 1.5%–3% solution in affected eye(s) twice daily

Titration Increase frequency to TID based on IOP response after 1–2 weeks

Usual maintenance dose 1 drop of 1.5%–3% solution in affected eye(s) 2–3 times daily

Maximum dose 3 drops per eye per day

Clinical Notes:

• Rarely first-line therapy; reserved for cases where prostaglandin analogues or beta-blockers are contraindicated or inadequate

• Apply punctal occlusion for 2–3 minutes after instillation to minimise systemic absorption

• Onset of miosis within 10–20 minutes; IOP reduction within 4 hours

• Avoid use in patients requiring night driving due to miosis-induced dim light vision difficulty

1. Miosis Induction During Ophthalmic Surgery (Cataract, Iridotomy)

Parameter Dosing

Starting dose 0.5 mL of 0.01% solution instilled into anterior chamber

Titration Not applicable

Usual maintenance dose Single intraoperative dose

Maximum dose 0.5 mL per procedure

Clinical Notes:

• Use only preservative-free intracameral preparation

• Produces rapid miosis within 2–5 seconds; duration 1–2 hours

• Never substitute topical ophthalmic drops for intracameral use

• Administer after lens implantation or as directed by surgical protocol

Secondary Indications — Adults (Off-label)

Indication Dose Evidence Basis Notes

NOT AVAILABLE in India — — Systemic or urologic use of carbachol is not practised in India due to safety concerns and lack of approved formulations

PAEDIATRIC DOSING (Specialist Only)

Primary Indications (Approved / Standard in India)

1. Paediatric Glaucoma (Congenital / Juvenile) – Adjunctive Use

Age Group Dosing Maximum

Infants <1 year NOT RECOMMENDED except in tertiary glaucoma centres —

Children 1–12 years 1 drop of 1.5% solution once or twice daily 2 drops/day per eye

Adolescents >12 years Adult dosing may be applied with caution 3 drops/day per eye

Clinical Notes:

• Mandatory specialist supervision by paediatric ophthalmologist

• Monitor closely for systemic cholinergic effects: excessive salivation, bronchospasm, bradycardia, sweating

• Regular IOP and pupil assessment required

• Use lowest effective concentration

Secondary Indications — Paediatrics (Off-label)

• No established off-label paediatric indications in Indian practice

Age Restriction Statement:

• Not recommended in infants below 1 year except under strict supervision in tertiary paediatric ophthalmology centres

• No adjustment required

• Negligible systemic absorption with ophthalmic administration

• Punctal occlusion further minimises any systemic exposure

• Known hypersensitivity to carbachol or any formulation excipient

• Active uveitis or iritis

• Acute intraocular inflammation

• Conditions where pupillary constriction is undesirable (e.g., acute angle-closure with pupillary block requiring mydriasis)

• Corneal abrasion or epithelial defect (topical use)

• Non-preservative-free formulation for intracameral use

• Bronchial asthma or COPD (risk of bronchospasm with systemic absorption)

• Peptic ulcer disease (cholinergic stimulation of gastric secretion)

• Cardiac disease including bradyarrhythmias

• Parkinsonism (may exacerbate symptoms)

• Epilepsy (lowered seizure threshold with systemic cholinergic effects)

• Retinal detachment risk factors (lattice degeneration, high myopia)

• Contact lens wearers (remove lenses before instillation; reinsert after 15 minutes)

• Night drivers or those working in dim light conditions (miosis impairs vision)

Parameter Recommendation

Risk category Insufficient human data; use only if clearly indicated

Preferred alternatives Timolol, latanoprost (more data in pregnancy for glaucoma)

When may be used Only when other agents are contraindicated or ineffective; benefit must outweigh risk

Monitoring Apply punctal occlusion; monitor for systemic cholinergic effects; fetal well-being monitoring if prolonged use

Parameter Recommendation

Compatibility Probably compatible; minimal systemic absorption

Drug levels in milk Expected to be very low to negligible

Preferred alternatives Timolol if glaucoma control required during lactation

Infant monitoring Observe for GI disturbances (diarrhoea, feeding difficulty) — unlikely with proper punctal occlusion

Parameter Recommendation

Starting dose 1 drop of 1.5% solution once daily

Titration Increase slowly (weekly intervals) based on IOP and tolerability

Special risks Increased sensitivity to systemic cholinergic effects (bradycardia, bronchospasm); falls risk due to dim-light vision impairment; brow ache; exacerbation of existing cardiac or respiratory disease

Monitoring Heart rate and respiratory status during initiation; regular ophthalmic review

Interacting Drug Effect Recommendation

Topical beta-blockers (timolol) Additive IOP reduction; increased risk of systemic bradycardia Monitor heart rate; avoid in patients with bradycardia

Systemic anticholinergics (atropine, glycopyrrolate, antihistamines) Antagonism of carbachol effect Reduced miotic and IOP-lowering efficacy; avoid concurrent use if possible

Flurbiprofen ophthalmic May reduce miotic effect Avoid concurrent intraoperative use

Interacting Drug Effect Recommendation

Cholinesterase inhibitors (neostigmine, pyridostigmine) Additive cholinergic effects Monitor for excess salivation, bradycardia, bronchospasm

Pilocarpine Additive miosis Generally avoid concurrent use; no added benefit

Systemic beta-blockers Additive cardiovascular effects if systemic absorption occurs Monitor heart rate and blood pressure

• Burning or stinging sensation upon instillation

• Ciliary spasm (brow ache, periorbital headache)

• Miosis (pupil constriction)

• Accommodative spasm (induced myopia)

• Dim or reduced vision especially in low light

• Conjunctival hyperaemia

• Lacrimation

• Transient blurred vision

Adverse Effect Clinical Action

Corneal oedema / decompensation Discontinue; ophthalmology review

Retinal detachment Rare; discontinue immediately; urgent surgical consultation

Bradycardia / Hypotension (from systemic absorption) Discontinue; supportive care; atropine if severe

Bronchospasm Discontinue; bronchodilator therapy; avoid future use

Anterior uveitis (with prolonged use) Discontinue; initiate topical steroids under specialist care

Allergic conjunctivitis / Periocular dermatitis Discontinue; consider alternative agent

Phase Parameters

Baseline Intraocular pressure; pupil size; slit-lamp examination for uveitis; retinal examination (especially in high myopes)

After initiation (1–2 weeks) IOP response; assess tolerability (headache, visual complaints); check for local irritation

Long-term IOP monitoring every 3–6 months; periodic fundus examination; visual field assessment if indicated; monitor for cataract progression with chronic miotic use

Brand Name Manufacturer Formulation

Miostat Alcon 0.01% intracameral solution (preservative-free)

Isopto Carbachol Alcon 1.5%, 3% ophthalmic solution

Carbachol Generic (various) Ophthalmic solution

No fixed-dose combinations available

• Not under NPPA price control (not on NLEM)

• Prices vary by brand and region

1. Reserve role in glaucoma — Carbachol is rarely first-line; prostaglandin analogues and beta-blockers are preferred. Use only when these are contraindicated or ineffective.

1. Punctal occlusion is essential — Apply nasolacrimal pressure for 2–3 minutes after instillation to minimise systemic absorption and cholinergic side effects.

1. Never interchange formulations for surgery — Intracameral use requires preservative-free 0.01% solution only; topical drops are toxic to intraocular structures.

1. Counsel about night vision — Miosis significantly impairs vision in dim light; advise patients to avoid night driving during treatment.

1. Brow ache is common — Ciliary muscle spasm causes periorbital headache, especially initially; usually improves with continued use. Reassure patients.

1. Retinal detachment risk — Use cautiously in high myopes or those with lattice degeneration; baseline and periodic fundus examination recommended.

carbachol; glaucoma; miotic; cholinergic agonist; parasympathomimetic; intraoperative miosis; cataract surgery; ophthalmology; muscarinic agonist; India-approved

RxIndia v1.0 — 01 Feb 2026

• CDSCO product inserts

• Indian Pharmacopoeia / NFI

• AIIMS Pharmacology Department Formulary

• API Textbook of Medicine — Glaucoma section

• Goodman & Gilman's The Pharmacological Basis of Therapeutics

• Indian Journal of Ophthalmology — clinical practice reviews

• AIOS (All India Ophthalmological Society) guidelines