Usage
Timolol + Travoprost is prescribed for the reduction of elevated intraocular pressure (IOP) in adult patients with open-angle glaucoma or ocular hypertension who are insufficiently responsive to topical beta-blockers or prostaglandin analogs alone. It combines two different classes of IOP-lowering medications for a synergistic effect.
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Pharmacological Classification:
- Timolol: Non-selective beta-adrenergic blocking agent (beta-blocker)
- Travoprost: Prostaglandin analog (specifically, a prostaglandin F2α analog)
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Mechanism of Action: Timolol decreases aqueous humor production, while travoprost increases uveoscleral outflow, both contributing to lower IOP.
Alternate Names
How It Works
- Pharmacodynamics: Timolol blocks beta-adrenergic receptors in the ciliary body, reducing aqueous humor production. Travoprost, a prostaglandin F2α analog, binds to prostaglandin FP receptors, primarily increasing uveoscleral outflow of aqueous humor.
- Pharmacokinetics: Both drugs are absorbed systemically after topical ocular administration. Timolol is metabolized primarily in the liver, while travoprost undergoes extensive metabolism both in the eye and systemically. Both are excreted primarily in the urine.
- Mode of Action:
- Timolol: Inhibition of β1 and β2 adrenergic receptors reduces cAMP production in the ciliary body, leading to decreased aqueous humor formation.
- Travoprost: Activation of FP receptors increases uveoscleral outflow through matrix metalloproteinase activity. Increased outflow through the trabecular meshwork may also play a minor role.
- Elimination Pathways:
- Timolol: Hepatic metabolism, renal excretion.
- Travoprost: Hydrolysis, beta-oxidation, glucuronidation, renal excretion.
Dosage
Standard Dosage
Adults:
One drop in the affected eye(s) once daily, either in the morning or evening. Administer at the same time each day. Do not exceed one drop per day per affected eye, as more frequent administration may decrease the IOP-lowering effect.
Children:
Use is not recommended for children and adolescents under 18 years of age, as safety and efficacy have not been established.
Special Cases:
- Elderly Patients: No dose adjustment is typically required.
- Patients with Renal Impairment: No dose adjustment is typically necessary.
- Patients with Hepatic Dysfunction: No dose adjustment is typically required.
- Patients with Comorbid Conditions: Use with caution in patients with cardiovascular diseases, respiratory diseases (like asthma or COPD), diabetes, and myasthenia gravis. Close monitoring is recommended.
Clinical Use Cases
Timolol + Travoprost is specifically indicated for chronic open-angle glaucoma and ocular hypertension. It is not intended for use in clinical situations like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations.
Dosage Adjustments
Dose adjustments are generally not required for elderly patients or those with hepatic or renal impairment. However, close monitoring is recommended for patients with comorbid conditions, especially those with cardiovascular or respiratory disease.
Side Effects
Common Side Effects:
Ocular: Eye redness, itching, burning, stinging, foreign body sensation, blurred vision, increased pigmentation of the iris and eyelashes, dry eye, tearing, eyelid changes (including deepening of the eyelid sulcus).
Systemic: Headache.
Rare but Serious Side Effects:
Macular edema, exacerbation of myasthenia gravis, new onset or exacerbation of arterial insufficiency, bradycardia, hypotension, bronchospasm.
Long-Term Effects:
Iris color change (increased brown pigmentation), growth of eyelashes.
Adverse Drug Reactions (ADR):
Severe allergic reactions (anaphylaxis), heart failure, bronchospasm, severe bradycardia.
Contraindications
- Hypersensitivity to either active substance or any of the excipients.
- Reactive airway disease (including bronchial asthma or a history of bronchial asthma) and severe chronic obstructive pulmonary disease (COPD).
- Sinus bradycardia, sick sinus syndrome, second- or third-degree atrioventricular block not controlled with a pacemaker, overt cardiac failure, cardiogenic shock.
Drug Interactions
- CYP2D6 inhibitors (e.g., quinidine, fluoxetine, paroxetine): May potentiate systemic beta-blockade.
- Oral calcium channel blockers, other beta-blockers, antiarrhythmics, digitalis glycosides, parasympathomimetics: May have additive effects leading to hypotension and/or marked bradycardia.
- Epinephrine: Timolol may decrease the response to epinephrine used to treat anaphylactic reactions.
- Clonidine: Timolol may enhance the hypertensive reaction to sudden withdrawal of clonidine.
- Antidiabetic agents: Timolol may potentiate the hypoglycaemic effects of antidiabetic agents.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: C (Travoprost may pose risk to the fetus and timolol can also cross the placenta potentially affecting the baby)
- Travoprost should not be used during pregnancy unless clearly necessary.
- Timolol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
- Breastfeeding: Timolol is present in human milk. Travoprost is present in animal milk but is not known if it is present in human milk. DuoTrav is not recommended during breastfeeding.
Drug Profile Summary
- Mechanism of Action: Timolol decreases aqueous humor production; Travoprost increases uveoscleral outflow.
- Side Effects: Ocular irritation, blurred vision, iris color change, bradycardia, hypotension.
- Contraindications: Asthma, COPD, bradycardia, heart block, heart failure.
- Drug Interactions: Beta-blockers, calcium channel blockers, CYP2D6 inhibitors, antidiabetics.
- Pregnancy & Breastfeeding: Not recommended.
- Dosage: One drop in affected eye(s) once daily.
- Monitoring Parameters: Intraocular pressure, heart rate, blood pressure, respiratory function.
Popular Combinations
Timolol + Travoprost is itself a popular combination. It is generally not combined with other topical IOP-lowering agents.
Precautions
- General Precautions: Evaluate patients for respiratory and cardiovascular conditions before initiating therapy. Monitor IOP regularly.
- Specific Populations: Avoid use in pregnancy and breastfeeding. Not recommended for children under 18. Use caution in patients with pre-existing heart or lung conditions, diabetes, or myasthenia gravis.
- Lifestyle Considerations: Driving may be impaired due to blurred vision.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Timolol + Travoprost?
A: One drop in the affected eye(s) once daily, in the morning or evening.
Q2: Can Timolol + Travoprost be used in children?
A: No, it is not recommended for use in children and adolescents below the age of 18 years.
Q3: What are the common side effects of Timolol + Travoprost?
A: Common side effects include eye redness, itching, burning or stinging, blurred vision, and changes in eyelash color and growth.
Q4: Are there any serious side effects I should be aware of?
A: While rare, serious side effects can include macular edema, worsening of myasthenia gravis, and exacerbation of arterial insufficiency. Systemic effects such as bradycardia and hypotension are also possible.
Q5: Can this medication be used during pregnancy or breastfeeding?
A: No, Timolol + Travoprost is generally not recommended during pregnancy and breastfeeding.
Q6: Can I use Timolol + Travoprost if I have asthma?
A: No, this medication is contraindicated in patients with asthma or severe COPD, as the timolol component can worsen respiratory function.
Q7: I missed a dose. Should I double up the next time?
A: No, do not double the dose. Simply administer the next dose as scheduled.
A: Yes, but remove your contact lenses before administering the drops and wait at least 15 minutes before reinserting them.
Q9: Can Timolol + Travoprost change my eye color?
A: Yes, it can slowly increase the amount of brown pigment in the iris, leading to a gradual darkening of the eye color, particularly in patients with greenish-brown, yellow-brown, or blue/gray-brown eyes. This change may be permanent.
Q10: What should I do if I experience any side effects?
A: Contact your ophthalmologist immediately if you experience any bothersome or persistent side effects, especially blurred vision, eye pain, or signs of an allergic reaction.
