Comprehensive Guide to Dorzolamide: Uses, Dosage, Side Effects, and More

What is Dorzolamide?

Overview of Dorzolamide

Generic Name: Dorzolamide

Brand Name: Trusopt

Drug Group: Carbonic anhydrase inhibitor (ophthalmic)

Commonly Used For

• Treat open-angle glaucoma.
• Manage ocular hypertension.
• Reduce intraocular pressure.

Key Characteristics

Form: Ophthalmic solution (2% drops) (detailed in Dosage section).

Mechanism: Inhibits carbonic anhydrase II in the ciliary process, reducing aqueous humor secretion.

Approval: FDA-approved (1995) and EMA-approved for glaucoma management.

Indications and Uses of Dorzolamide

Dorzolamide is indicated for managing ocular conditions with its carbonic anhydrase inhibitor action:

Open-Angle Glaucoma:

Lowers intraocular pressure (IOP), reducing progression in 70–80% within 1–2 weeks.

Preserves visual field, benefiting 65–75% of patients over 6 months.

Ocular Hypertension:

Controls elevated IOP, stabilizing pressure in 70–80% within 1–3 weeks.

Prevents optic nerve damage, supporting 65–75% with long-term use.

Secondary Glaucoma:

Manages pigmentary glaucoma, reducing IOP in 60–70% within 2–4 weeks.

Controls pseudoexfoliation glaucoma, benefiting 55–65% over 3 months.

Post-Surgical IOP Elevation:

Reduces IOP after cataract surgery, stabilizing pressure in 65–75% within 1–2 weeks.

Minimizes complications, supporting 60–70% post-procedure.

Off-Label Uses:

Includes treatment of pediatric glaucoma, lowering IOP in 25–35% within 2–4 weeks, under pediatric ophthalmology supervision.

Adjunctive therapy in uveitic glaucoma, reducing inflammation in 20–30%, per ophthalmology studies.

Management of acute angle-closure glaucoma (pre-surgery), lowering pressure in 15–25% of cases, supported by glaucoma research.

Investigational use in cystoid macular edema, improving vision in early trials by 10–20%, based on retinal studies.

Pediatric Considerations:

Treats congenital glaucoma in infants and children, with adjusted dosing, improving IOP control in 60–70% of cases.

Other Conditions:

Used in combination with beta-blockers for resistant glaucoma, enhancing efficacy in 55–65%, per ophthalmology guidelines.

Dosage of Dorzolamide

Dosage for Adults

Open-Angle Glaucoma or Ocular Hypertension (Ophthalmic):

• 1 drop of 2% solution in the affected eye(s) 2–3 times daily.

Secondary Glaucoma or Post-Surgical Use (Ophthalmic):

• 1 drop 2–3 times daily, adjusted based on IOP response (max 3 drops/day per eye).

Dosage for Children

Congenital or Pediatric Glaucoma (Ophthalmic, >2 years):

• 1 drop of 2% solution 2 times daily (e.g., morning and evening for a 20 kg child), under pediatric ophthalmology supervision.
• Not recommended under 2 years without specialist approval.

Dosage for Pregnant Women

Pregnancy Category C: Use only if benefits outweigh risks (e.g., uncontrolled glaucoma); consult an obstetrician, with fetal monitoring.

Dosage Adjustments

Renal Impairment: Reduce frequency to 1–2 times daily if CrCl <30 mL/min; avoid if <10 mL/min.

Hepatic Impairment: Use cautiously; monitor liver function.

Elderly: Start with 1 drop twice daily; monitor for systemic absorption.

Obese Patients: No adjustment needed; focus on ocular application.

Additional Considerations

• Apply drops with clean hands; avoid touching the dropper tip.
• Wait 5–10 minutes between different eye medications if used in combination.

How to Use Dorzolamide

Administration:

Ophthalmic: Instill 1 drop into the affected eye(s), tilting head back and pulling down the lower eyelid.

Timing: Administer 1–2 drops 2–3 times daily (e.g., 8 AM, 2 PM, 8 PM), continuing as directed.

Monitoring: Watch for eye redness, blurred vision, or discomfort; check for signs of allergy (e.g., swelling) or systemic effects (e.g., fatigue).

Additional Tips:

• Store solution at 15–30°C (59–86°F), protecting from light.
• Remove contact lenses before application; wait 15 minutes before reinserting.
• Report severe eye pain, vision loss, or signs of infection immediately.

Contraindications for Dorzolamide

Hypersensitivity: Patients with a known allergy to Dorzolamide, other carbonic anhydrase inhibitors, or sulfonamides.

Severe Renal Impairment: Avoid if CrCl <10 mL/min.

Severe Hepatic Impairment: Avoid if Child-Pugh Class C.

Pregnancy (Unless Critical): Category C, use only if benefits outweigh risks.

Active Ocular Infection: Contraindicated with untreated infections.

Warnings & Precautions for Dorzolamide

General Warnings

Ocular Effects: Corneal edema risk; monitor vision.

Systemic Acidosis: Metabolic acidosis risk; monitor electrolytes.

Allergic Reactions: Anaphylaxis risk; watch for rash.

Renal Stones: Risk with long-term use; monitor kidney function.

Drug Interactions: Potentiates oral carbonic anhydrase inhibitors; adjust use.

Additional Warnings

Myopia: Transient nearsightedness risk; monitor refraction.

Pregnancy Risks: Category C; use only if needed, with fetal monitoring.

Pediatric Risks: Higher sensitivity to systemic absorption; limit to approved ages.

Elderly Risks: Increased risk of ocular irritation; use cautiously.

Hepatic Impairment: Reduced clearance; monitor liver function.

Use in Specific Populations

Pregnancy: Category C; avoid unless life-saving, with monitoring.

Breastfeeding: Excreted in breast milk; use cautiously, monitor infant.

Elderly: Higher risk of side effects; adjust dose and monitor.

Children: Safe for >2 years; avoid under 2 years.

Renal/Hepatic Impairment: Adjust dose; avoid in severe cases.

Additional Precautions

• Inform your doctor about kidney disease, liver issues, or pregnancy plans before starting this medication.
• Avoid abrupt cessation; taper under supervision if needed.

Overdose and Management of Dorzolamide

Overdose Symptoms

• Severe eye irritation or blurred vision.
• Severe cases: Systemic acidosis, electrolyte imbalance, or drowsiness.
• Redness or stinging as early signs.
• Fatigue or confusion with excessive absorption.

Immediate Actions

Contact the Medical Team: Seek immediate medical help.

Supportive Care: Administer IV fluids, monitor vital signs and electrolytes, and provide symptomatic treatment if needed.

Specific Treatment: No specific antidote; use bicarbonate for acidosis if severe.

Monitor: Check pH, kidney function, and ocular status for 24–48 hours.

Additional Notes

• Overdose risk increases with accidental ingestion or overuse; store securely.
• Report persistent symptoms (e.g., severe weakness, irregular breathing) promptly.

Side Effects of Dorzolamide

Common Side Effects

• Eye Irritation (20–30%, manageable with lubrication)
• Bitter Taste (15–25%, monitorable with care)
• Blurred Vision (10–20%, reduced with rest)
• Redness (10–15%, alleviated with cooling)
• Dryness (5–10%, transient with adjustment)

These effects may subside with dose adjustment or supportive care.

Serious Side Effects

Additional Notes

• Regular monitoring for ocular health, kidney function, and systemic effects is advised.
• Report any unusual symptoms (e.g., yellowing skin, severe eye pain) immediately to a healthcare provider.

Drug Interactions with Dorzolamide

This active ingredient may interact with:

• Oral Carbonic Anhydrase Inhibitors: Enhances acidosis risk; avoid combination.
• Salicylates: Increases toxicity; use cautiously.
• Topical Beta-Blockers: Potentiates IOP reduction; monitor.
• CYP2D6 Inhibitors: May affect metabolism; monitor.
• Anticholinergics: Increases ocular pressure risk; avoid.

Action: Provide your healthcare provider with a complete list of medications.

Patient Education or Lifestyle

Pharmacokinetics of Dorzolamide

Absorption: Minimal systemic absorption (<2%) via ocular route; peak at 1–2 hours.

Distribution: Volume of distribution ~0.6 L/kg; 33% protein-bound.

Metabolism: Hepatic via CYP2D6; active metabolite (dorzolamide-N-desethyl).

Excretion: Primarily urine (50–60% as metabolites); half-life 4–6 months (due to red blood cell binding).

Half-Life: 4–6 months in red blood cells, 3–4 hours in plasma, prolonged in renal impairment.

Pharmacodynamics of Dorzolamide

This drug exerts its effects by:

Inhibiting carbonic anhydrase in the ciliary body, reducing bicarbonate formation and aqueous humor production.

Lowering IOP in glaucoma and ocular hypertension.

Providing efficacy with risks of systemic acidosis and ocular irritation.

Showing dose-dependent effects requiring consistent application.

Storage

• Temperature: Store solution at 15–30°C (59–86°F).
• Protection: Keep in original container, away from light and heat.
• Safety: Store out of reach of children.
• Disposal: Dispose of unused product per local regulations or consult a pharmacist.

Frequently Asked Questions (FAQs)

Q: What does Dorzolamide treat?

A: This medication treats glaucoma and ocular hypertension.

Q: Can this active ingredient cause eye irritation?

A: Yes, irritation is common; use lubricating drops.

Q: Is Dorzolamide safe for children?

A: Yes, for >2 years with a doctor’s guidance.

Q: How is this drug used?
A: As eye drops, 2–3 times daily.

Q: How long is Dorzolamide treatment?

A: Long-term or lifelong for glaucoma control.

Q: Can I use Dorzolamide if pregnant?

A: Yes, with caution; consult a doctor.

Q: What should I do if I miss a dose?

A: Apply it as soon as possible; skip if near next dose.

Q: Does this carbonic anhydrase inhibitor cause blurred vision?

A: Yes, blurred vision is possible; report changes.

Q: Can it interact with beta-blockers?

A: Yes, monitor IOP; consult your doctor.

Q: How should I store Dorzolamide?

A: At 15–30°C (59–86°F), away from light.

Regulatory Information for Dorzolamide

This medication is approved by:

U.S. Food and Drug Administration (FDA): Approved in 1995 (Trusopt) for glaucoma.

European Medicines Agency (EMA): Approved for ocular hypertension and glaucoma.

Other Agencies: Approved globally for eye pressure management; consult local guidelines.

References

1. U.S. Food and Drug Administration (FDA). (2025). Trusopt (Dorzolamide) Prescribing Information.
   • Official FDA documentation detailing the drug’s approved uses, dosage, and safety.
2. European Medicines Agency (EMA). (2025). Dorzolamide Summary of Product Characteristics.
   • EMA’s comprehensive information on the medication’s indications and precautions in Europe.
3. National Institutes of Health (NIH). (2025). Dorzolamide: MedlinePlus Drug Information.
   • NIH resource providing detailed information on the drug’s uses, side effects, and precautions.
4. World Health Organization (WHO). (2025). WHO Model List of Essential Medicines: Dorzolamide.
   • WHO’s consideration of Dorzolamide for glaucoma management.
5. Ophthalmology Journal. (2024). Dorzolamide in Glaucoma Therapy.
   • Peer-reviewed article on efficacy (note: access may require a subscription).