1. Introduction
Timolol is a non-selective beta-blocker used in ophthalmology to reduce intraocular pressure (IOP) in conditions like glaucoma and ocular hypertension. It works by reducing aqueous humour production in the eye, thereby lowering IOP and preventing optic nerve damage.
2. Indications
- Primary Open-Angle Glaucoma (POAG)
- Ocular Hypertension
- Secondary Glaucoma (e.g., post-surgical, inflammatory glaucoma)
- Prevention of Increased IOP After Laser Eye Surgery
3. Dosage
Adults & Elderly:
- Standard Dose (0.25% or 0.5% solution):
- One drop into the affected eye(s) twice daily (morning and evening).
- May be reduced to once daily if adequate control is achieved.
- Combination Therapy:
- Can be used with other IOP-lowering agents like prostaglandin analogues (latanoprost, bimatoprost) if IOP is not controlled with monotherapy.
Children & Infants (Off-Label Use):
- 0.25% Solution: One drop once or twice daily, depending on severity.
Renal Impairment:
- No dose adjustment required, but monitor for systemic absorption effects.
Hepatic Impairment:
- No dose adjustment needed, but use with caution in severe hepatic disease.
4. Administration
- Wash hands before use.
- Tilt the head back and pull the lower eyelid down to create a pocket.
- Instil one drop into the conjunctival sac.
- Close the eye and press lightly on the inner corner (nasolacrimal occlusion) for 1–2 minutes to reduce systemic absorption.
- Wait at least 5 minutes before using other eye drops.
- Do not touch the dropper tip to the eye or any surface to avoid contamination.
5. Forms Available
- Eye Drops (Timolol Maleate Solution): 0.25% and 0.5% (5 mL bottle)
- Gel-Forming Solution: 0.25% and 0.5% (longer duration, applied once daily)
6. Side Effects
6.1 Common Side Effects:
- Eye irritation or redness
- Blurred vision
- Dry eyes
6.2 Less Common Side Effects:
- Eye pain
- Sensitivity to light (photophobia)
- Mild burning or stinging sensation
6.3 Rare but Serious Side Effects (Systemic Absorption):
- Bradycardia (slow heart rate)
- Hypotension (low blood pressure)
- Bronchospasm (especially in asthmatic patients)
- Fatigue or dizziness
- Depression or confusion (especially in elderly patients)
7. Warnings
- Systemic Absorption: Timolol can be absorbed into the bloodstream, causing cardiovascular and respiratory effects.
- Bronchospasm & Asthma: Avoid in patients with asthma or severe COPD.
- Bradycardia & Heart Block: Avoid in patients with heart failure, bradycardia, or AV block.
- Masking of Hypoglycaemia Symptoms: Caution in diabetic patients using insulin or oral hypoglycaemics.
- Sudden Withdrawal Risk: Do not stop abruptly, as it may cause rebound hypertension or glaucoma progression.
8. Precautions
- Use with caution in elderly patients due to increased risk of systemic absorption.
- Avoid in patients with severe peripheral vascular disease (Raynaud’s phenomenon).
- Can exacerbate myasthenia gravis symptoms.
- Use nasolacrimal occlusion (pressing inner eye corner) to reduce systemic absorption.
9. Interactions
- Beta-Blockers (Oral e.g., propranolol, atenolol): Increased risk of bradycardia and hypotension.
- Calcium Channel Blockers (e.g., verapamil, diltiazem): Additive cardiac effects; risk of bradycardia.
- Digitalis Glycosides (e.g., digoxin): Increased risk of bradycardia and heart block.
- Adrenergic Agonists (e.g., epinephrine): May reduce the effectiveness of timolol.
- Clonidine: Rebound hypertension risk when discontinued suddenly.
10. Monitoring Parameters
- Intraocular Pressure (IOP): Regular monitoring to assess treatment effectiveness.
- Heart Rate & Blood Pressure: In patients with cardiovascular disease.
- Respiratory Function: In patients with asthma or COPD.
11. Use in Children
- Used off-label for paediatric glaucoma, but requires careful dosing.
- Infants should be closely monitored for systemic side effects.
12. Use in Pregnancy
- Category C:
- Use only if benefits outweigh risks.
- May cause fetal bradycardia if systemically absorbed.
13. Use in Elderly
- Increased risk of systemic effects (hypotension, bradycardia, confusion).
- Monitor for cognitive changes (fatigue, depression).
14. Use in Kidney Disease
- No dose adjustment required, but monitor for systemic absorption effects.
15. Use in Liver Disease
- No dose adjustment required, but caution in severe hepatic disease.
16. Patient Counselling Points
- Use exactly as prescribed; do not stop suddenly.
- Press on the inner eye corner (nasolacrimal occlusion) for 1–2 minutes to reduce systemic absorption.
- Do not touch the dropper tip to prevent contamination.
- Wait 5 minutes before using other eye drops.
- Blurred vision may occur temporarily after application—avoid driving immediately after use.
- Report signs of breathing difficulty, slow heart rate, or dizziness to your doctor.
17. Table of Brand Names, Manufacturer, and Prices in USD
Brand Name | Manufacturer | Strength/Dosage Form | Price (USD) |
---|---|---|---|
Timoptic | Bausch & Lomb | 0.25% Eye Drops (5 mL) | $30 (1 bottle) |
Timoptic-XE | Bausch & Lomb | 0.5% Gel-Forming Drops | $35 (1 bottle) |
Betimol | Santen | 0.25% & 0.5% Eye Drops | $25 (1 bottle) |
Generic Timolol | Various | 0.5% Eye Drops (5 mL) | $10 (1 bottle) |
18. 15 FAQs (Frequently Asked Questions)
1. What is Timolol used for?
It is used to lower intraocular pressure (IOP) in glaucoma and ocular hypertension.
2. How does Timolol work?
It reduces aqueous humour production, thereby lowering IOP.
3. Can Timolol cause blurry vision?
Yes, temporary blurry vision may occur after application.
4. Can Timolol affect breathing?
Yes, it can cause bronchospasm, especially in asthmatic patients.
5. Can I use Timolol with other eye drops?
Yes, but wait at least 5 minutes between different eye medications.
6. Can Timolol cause heart problems?
Yes, it can cause bradycardia, hypotension, and heart failure symptoms in susceptible patients.
7. Can I stop Timolol suddenly?
No, sudden withdrawal may worsen IOP or lead to systemic effects.
8. Can pregnant women use Timolol?
Use only if benefits outweigh risks due to fetal bradycardia risk.
9. Is Timolol safe for elderly patients?
Yes, but monitor for hypotension, bradycardia, and cognitive effects.
10. Can I drive after using Timolol?
Wait until vision clears before driving.