TRAVONORM OPHTALMIC SOLUTION

Indications

• Open-angle glaucoma
• Ocular hypertension

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: Apply once daily, preferably in the evening.

Mechanism of action

Travoprost is a prodrug that is hydrolyzed to its active metabolite, travoprost free acid, after absorption through the cornea. This active form exhibits full agonist activity at the prostaglandin FP receptor, which increases the outflow of aqueous humour via trabecular meshwork and uveoscleral pathways, leading to reduced intraocular pressure.

Pharmacodynamics

Travoprost has a strong affinity for the prostaglandin FP receptor, showing full agonist activity within the nanomolar range. It demonstrates no significant affinity for other prostanoid or non-prostanoid receptors. The reduction in intraocular pressure begins approximately two hours post-administration, with peak effects occurring at around 12 hours, and sustained effects lasting over 24 hours from a single dose.

Pharmacokinetics

After ocular administration, travoprost is rapidly absorbed through the cornea and converted to travoprost free acid. The active metabolite's pharmacokinetic profile supports its efficacy in lowering intraocular pressure. Specific details on the distribution, metabolism, and excretion of travoprost remain limited, but its effects are largely localized to the eye.

Contra-indications

• Hypersensitivity to travoprost or any of its excipients
• Active intraocular inflammation
• Angle-closure glaucoma

Adverse effects

• Hypertrichosis
• Dry eye
• Eye discolouration
• Madarosis
• Increased pigmentation of the iris
• Eye irritation
• Asthma exacerbation
• Ocular inflammation

Interactions

• May enhance the effect of other intraocular pressure-lowering medications
• Caution with concomitant use of other prostaglandin analogues

Precautions

• Use with caution in patients with a history of asthma or respiratory disorders
• May cause changes in eye colour; particularly caution in patients with mixed coloured irides
• Patients should be advised to avoid repeated contact of the eye drop solution with skin

Pregnancy

Manufacturer advises to avoid unless potential benefit outweighs risk, as toxicity has been observed in animal studies.

Breast-feeding

Manufacturer advises to avoid, as travoprost is present in milk in animal studies.

Storage

Store at room temperature, away from light. After opening, use within 28 days.

Formulations

• {'name': 'Travoprost eye drops', 'strength': '15 micrograms/ml', 'volume': '2.5 ml'}
• {'name': 'Travoprost preservative-free eye drops', 'strength': '15 micrograms/ml', 'volume': '30 unit dose vials'}

Mechanism of action

Travoprost is a prodrug. Upon administration, travoprost is absorbed through the cornea and hydrolyzed to its active metabolite, travoprost free acid. The ester moiety of the free acid allows for enhanced penetration into the aqueous humour. While the exact mechanism of travoprost is largely unknown, it is believed to be related to its full agonist activity for the prostaglandin FP receptor. By binding to the FP receptor, travoprost free acid increases the outflow of aqueous humour via the trabecular meshwork and uveoscleral pathways, thereby reducing the intraocular pressure.

Pharmacodynamics

Travoprost demonstrates preferential affinity and full agonist activity for the prostaglandin FP receptor in the nanomolar range. Travoprost shows no significant affinity for other prostanoid or non-prostanoid receptors. Travoprost-induced reduction of intraocular pressure is observed about two hours after administration, and the maximum effect is reached after 12 hours. Significant lowering of intraocular pressure can be maintained for periods exceeding 24 hours with a single dose.