XALAPROST

MIMS Revision Date: 01 May 2023

1 Name of Medicine

Latanoprost.

2 Qualitative and Quantitative Composition

Each mL of the Xalaprost eye drop solution contains 50 micrograms of latanoprost as the active ingredient.
Each bottle contains 2.5 mL eye drop solution corresponding to a minimum of 80 drops of solution. One drop contains approximately 1.5 micrograms latanoprost.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Eye drops, solution.
The solution is a clear and colourless solution.

4 Clinical Particulars

4.1 Therapeutic Indications

Reduction of elevated intraocular pressure in patients with open angle glaucoma or ocular hypertension.

4.2 Dose and Method of Administration

For individual patient use only.
Recommended dosage for adults (including the elderly). Recommended therapy is one eye drop in the affected eye(s) once daily. Optimal effect is obtained if latanoprost eye drops is administered in the evening. Systemic absorption can be minimised by pressure on the tear duct immediately after application of the eye drop.
If one dose is missed treatment should continue with the next dose as normal.
The dosage of Xalaprost should not exceed once daily since it has been shown that more frequent administration decreases the intraocular pressure lowering effect.
Administration. Latanoprost eye drops is effective as a single drug therapy but can also be used in combination with beta-adrenergic antagonists (timolol), adrenergic agonists (dipivefrine hydrochloride), cholinergic agonists (pilocarpine) and carbonic anhydrase inhibitors (acetazolamide) to achieve an additive effect. In case of combined therapy the eye drop products should be administered with an interval of at least five minutes.
Use with contact lenses. The contact lenses should be removed before instillation of the eye drops and may be reinserted after 15 minutes (see Section 4.4 Special Warnings and Precautions for Use).

4.3 Contraindications

Known hypersensitivity to latanoprost or any of the excipients in Xalaprost.

4.4 Special Warnings and Precautions for Use

Latanoprost may gradually change eye colour by increasing the amount of brown pigment in the iris. Before treatment is instituted, patients should be informed of the possibility of a permanent change in eye colour. Unilateral treatment can result in heterochromia.
This change in eye colour has predominantly been seen in patients with mixed colour irides i.e. blue brown, grey brown, green brown or yellow brown. The highest incidence was found in patients with green brown and yellow brown irides. In patients with homogeneously blue eyes, no change has been observed and in patients with homogenously grey, green or brown eyes, the change has only rarely been seen. The onset of the change is usually within the first eight months of treatment, but may occur later in a small number of patients (see Section 5.1 Pharmacodynamic Properties, Clinical trials).
The colour change is due to increased melanin content in the stromal melanocytes of the iris and not to an increase in the number of melanocytes. Typically, the brown pigmentation around the pupil spreads concentrically towards the periphery in affected eyes, but the entire iris or parts of it may become more brownish. Patients who develop increased iris pigmentation should be examined regularly and, depending on the clinical situation, treatment may be stopped. No further increase in brown iris pigment has been observed after discontinuation of treatment, but the resultant colour change may be permanent. It has not been associated with any symptom or pathological changes in clinical trials of up to 48 months duration.
Naevi or freckles of the iris have not been affected by treatment.
Accumulation of pigment in the trabecular meshwork or elsewhere in the anterior chamber has not been observed in long-term clinical trials.
Eyelid and eyelash changes. Eyelid skin darkening, which may be reversible, has been reported in association with the use of latanoprost.
Latanoprost may gradually change eyelashes and vellus hair in the treated eye; these changes include increased length, thickness, pigmentation and number of lashes or hairs, and misdirected growth of eyelashes. Eyelash changes are reversible upon discontinuation of treatment.
Use with caution in the following circumstances. Macular oedema. Including cystoid macular oedema, has been reported uncommonly during treatment with latanoprost. These reports have mainly occurred in patients with aphakia or pseudophakia with anterior chamber lenses and/or torn posterior lens capsule, or in patients with known risk factors for macular oedema. Caution is recommended when using latanoprost in these patients. Upon discontinuation of latanoprost treatment, visual acuity has improved, in some cases with concurrent treatment with topical steroidal and nonsteroidal anti-inflammatory drugs.
Glaucoma. There is no experience with latanoprost in inflammatory and neovascular glaucoma, inflammatory ocular conditions or congenital glaucoma. There is limited experience with latanoprost in chronic angle closure glaucoma (one 12 week study), open angle glaucoma of pseudophakic patients (4 out of 519 patients enrolled in the long-term safety study were pseudophakic patients) and in pigmentary glaucoma (one 12 month study). Latanoprost has no or little effect on the pupil, but there is no experience in acute attacks of closed angle glaucoma. Latanoprost should be used with caution in these conditions until more experience is obtained.
Use with contact lenses. Xalaprost contains benzalkonium chloride which may be absorbed by contact lenses. The contact lenses should be removed before instillation of the eye drops and may be reinserted after 15 minutes.
Asthma. There is no experience in patients with severe or brittle asthma. Such patients should therefore be treated with caution until there is sufficient experience (see Section 4.8 Adverse Effects (Undesirable Effects)).
Herpetic keratitis. Use with caution in patients with a history of herpetic keratitis, it should be avoided in cases of active herpes simplex keratitis and in patients with a history of recurrent herpetic keratitis specifically associated with prostaglandin analogues.
Use in the elderly. No data available.
Paediatric use. Latanoprost eye drops is not recommended for use in children. Use in children has not been studied.
Effects on laboratory tests. No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Interactions with other medications other than those described in Section 5.1 Pharmacodynamic Properties, Clinical trials, have not been investigated.
There have been reports of paradoxical elevations in IOP (intra-ocular pressure) following the concomitant ophthalmic administration of two prostaglandin analogues. Therefore, the use of two or more prostaglandins, prostaglandin analogues, or prostaglandin derivatives is not recommended.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility. Latanoprost had no effect on male or female fertility studies in rats when administered intravenously with 250 micrograms/kg.
Use in pregnancy. (Category B3)
The safety of latanoprost eye drops for use in human pregnancy has not been established. Reproductive studies have been performed in rats and rabbits and no malformations or structural variations were observed in the fetuses at any doses of latanoprost. In rabbits given latanoprost IV at 5 micrograms/kg/day, a slight increase of litter resorption occurred and at doses of 50 or 300 micrograms/kg/day, total litter resorption (100%) in all animals was recorded. A dose of 1 micrograms/kg/day was well tolerated in rabbits.
In pregnant rats dosed with tritium labelled latanoprost intravenously, the radioactivity was detected in all maternal tissues, placenta and fetus.
Latanoprost eye drops should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Use in lactation. There are limited experimental animal and no human data available on the pharmacokinetics of latanoprost eye drops in lactation. The active substance in latanoprost eye drops and its metabolites may pass into breast milk and latanoprost eye drops should therefore be used with caution in nursing women.
The benefits of treatment with latanoprost eye drops should clearly outweigh the possible risks for use in nursing mothers.

4.7 Effects on Ability to Drive and Use Machines

In common with other eye preparations, installation of eye drops may cause transient blurring of vision. Until this has resolved, patients should not drive or use machines.

4.8 Adverse Effects (Undesirable Effects)

Adverse events occurring at a frequency of > 1% in 6 month comparative trials are presented in Table 1.

Adverse reactions (also see Section 4.4 Special Warnings and Precautions for Use). Most of the adverse events reported for latanoprost relate to the ocular system. The adverse reactions are summarised below according to frequency and organ class.
Very common (> 10% patients). Ocular. Increased iris pigmentation; eye irritation (burning, grittiness, itching, stinging and foreign body sensation); eyelash and vellus hair changes (pigmentation, thickening, lengthening, increased number).
Common (1-10% patients). Ocular. Mild to moderate conjunctival hyperaemia; punctate keratitis (mostly without symptoms); blepharitis; eye pain; conjunctivitis; vision blurred; eyelid oedema; localised skin reaction on the eyelids.
Musculoskeletal and connective tissue disorders. Myalgia, arthralgia.
Nervous system disorders. Dizziness; headache.
Skin and subcutaneous tissue disorders. Skin rash.
Uncommon (< 1% patients). Ocular. Iritis/ uveitis; keratitis; macular oedema including cystoid macular oedema, photophobia.
General disorders and administration site conditions. Nonspecific chest pain.
Respiratory, thoracic and mediastinal disorders. Asthma; dyspnoea.
Rare (< 0.1% patients). Ocular. Symptomatic corneal oedema and erosions; periorbital oedema; darkening of the palpebral skin of the eyelids; periorbital and lid changes; resulting in deepening of the eyelid sulcus; trichiasis.
Respiratory, thoracic and mediastinal disorders. Asthma aggravation; acute asthma attacks.
Infections and infestations. Herpetic keratitis.
Additional information for selected adverse reactions. Iris pigmentation changes. Latanoprost eye drops may cause an increase in brown pigmentation of the iris, predominantly in patients with mixed coloured irides (i.e. blue brown, grey brown, green brown, yellow brown). This is due to increased melanin content in the stromal melanocytes of the iris (see Section 4.4 Special Warnings and Precautions for Use).
Macular oedema. Macular oedema has been reported uncommonly during latanoprost eye drop treatment. These reports have mainly occurred in aphakic patients, in pseudophakic patients with torn posterior lens capsule or anterior chamber lens, or in patients with known risk factors for cystoid macular oedema (such as diabetic retinopathy and retinal vein occlusion). An association between the use of latanoprost eye drops and unexplained macular oedema cannot be excluded (see Section 4.4 Special Warnings and Precautions for Use).
Iritis/ uveitis. Cases of iritis/ uveitis have been uncommonly reported. The majority of patients in these cases had concomitant predisposing factors for developing iritis/ uveitis.
Asthma/ dyspnoea. Cases of asthma and dyspnoea have been uncommonly reported. Rare cases of asthma aggravation and acute asthma attacks have also been reported. There is limited experience from patients with asthma, but latanoprost has not been found to affect the pulmonary function when studied in a small number of steroid and nonsteroid treated patients suffering from moderate asthma. There is no experience in patients with severe or brittle asthma and such patients should therefore be treated with caution until there is sufficient experience.
Post-marketing experience. Eye disorders. Pseudopemphigoid of ocular conjunctiva, iris cyst.
Cardiac disorders. Angina, palpitations, angina unstable.
Gastrointestinal disorders. Nausea; vomiting.
Skin and subcutaneous tissue disorders. Pruritus.
Adverse reactions for eyedrops containing phosphate buffers. Cases of corneal calcification have been reported very rarely in association with the use of phosphate containing eye drops in some patients with significantly damaged corneas.
Reporting suspected adverse effects. Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems.

4.9 Overdose

Symptoms. Apart from ocular irritation and conjunctival or episcleral hyperaemia, the ocular effects of latanoprost administered at high doses are not known.
Treatment. If overdosage with Xalaprost occurs, treatment should be symptomatic and supportive. If Xalaprost is accidentally ingested the following information may be useful: one bottle contains 125 micrograms latanoprost. More than 90% is metabolised during the first pass through the liver. Intravenous infusion of 3 micrograms/kg in healthy volunteers induced no symptoms but a dose of 5.5-10 micrograms/kg caused nausea, abdominal pain, dizziness, fatigue, hot flushes and sweating. In patients with bronchial asthma bronchoconstriction was not induced by latanoprost when applied topically on the eyes in a dose of seven times the clinical dose of latanoprost eye drops.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action. Latanoprost, a selective prostaglandin F_2α analogue, is a selective prostanoid FP receptor agonist which reduces the intraocular pressure by increasing the outflow of aqueous humour. Reduction of the intraocular pressure in man starts about three to four hours after administration and maximum effect is reached after 8 to 12 hours. Pressure reduction is maintained for at least 24 hours.
Studies in animals and man indicate that the main mechanism of action is increased uveoscleral outflow, although some increase in outflow facility (decrease in outflow resistance) has been reported in man.
Clinical trials have shown that latanoprost has no significant effect on the production of aqueous humour. Latanoprost has not been found to have any effect on the blood aqueous barrier.
Latanoprost has no or negligible effects on the intraocular blood circulation when used at the human clinical dose, as studied in monkeys. However, mild to moderate conjunctival or episcleral hyperaemia may occur during topical treatment.
Chronic treatment with latanoprost in monkey eyes which had undergone extracapsular lens extraction did not affect the retinal blood vessels as determined by fluorescein angiography.
Latanoprost has not induced fluorescein leakage in the posterior segment of pseudophakic human eyes during short-term treatment.
Latanoprost in clinical doses has not been found to have any significant pharmacological effects on the cardiovascular or respiratory systems.
Clinical trials. Efficacy. In three pivotal, randomised, double blind, parallel group trials latanoprost 50 micrograms/mL once a day was compared with timolol 5 mg/mL twice a day. Across the three trials, 460 patients received latanoprost and 369 received timolol. At 6 months latanoprost reduced intraocular pressure (IOP) by 27-34% from the untreated baseline of 24.4-25.2 mmHg and timolol reduced IOP by 20-33% from a baseline of 24.1-25.4 mmHg. In one of these three studies, the difference between the reduction in IOP by latanoprost versus timolol was statistically significant (p < 0.001). A meta-analysis of the three trials demonstrated that of the intention to treat population, 61% of latanoprost treated patients, compared with 40% of timolol treated patients, reached a 30% reduction in diurnal IOP after 6 months. No tolerance to the effect of latanoprost was seen after 12 months in these trials.
The pivotal studies have demonstrated that latanoprost is effective as monotherapy. In addition, latanoprost is effective as adjunctive therapy in reduction of IOP.
Short-term (1 or 2 week) studies suggest the effect of latanoprost is additive in combination with adrenergic agonists (dipivefrine hydrochloride), carbonic anhydrase inhibitors (acetazolamide) and at least partly additive with cholinergic agonists (pilocarpine). Although intended primarily as a safety study, IOP reduction was effectively maintained over 48 months in a clinical trial of 356 patients receiving latanoprost as adjunctive therapy to various medications including β-adrenergic antagonists, adrenergic agonists, cholinergic agonists and carbonic anhydrase inhibitors. Out of 519 patients at study start, only 7 patients were withdrawn from the study due to uncontrolled IOP.
Clinical trials involving a fixed combination of latanoprost 50 micrograms/mL and timolol 5 mg/mL given once daily have also been conducted. The mean diurnal IOP lowering effect of the combination was greater than that produced by monotherapy with either latanoprost 50 micrograms/mL once daily or timolol 5 mg/mL bd.
Safety. Long-term safety of latanoprost has been investigated in an open label, multicentre, safety study. This trial enrolled 519 patients, 356 of whom continued for 48 months. Iris pigmentation changes have been observed in patients of the pivotal clinical trials of latanoprost (also see Section 4.4 Special Warnings and Precautions for Use; Section 4.8 Adverse Effects (Undesirable Effects)). The long-term safety study has shown that this change is not associated with any increased risk of clinically significant ocular or systemic effects, nor is it considered to have any long-term consequences.
In those patients experiencing colour change, the time to onset of increased iris pigmentation usually occurred within 8 months of starting treatment. Within 24 months, onset had occurred in almost all of these cases. Onset after 36 months of treatment was very rare. Using iris photography, the increase in iris pigmentation was graded as 'weak' in 75 out of 124 patients (60.5%) during the first year of onset. A weak grading was maintained in 42 of these patients (33.9%) over 48 months of treatment. In those patients showing iris pigmentation progression, there was no apparent increase in iris pigmentation during the fourth year of treatment, indicating a plateau in pigmentation had been reached. A separate safety study has also shown that reintroduction of latanoprost to patients with increased iris pigmentation will not necessarily lead to a further increase in iris pigmentation severity.
IOP reduction between patients who developed iris pigmentation, and those who did not, was shown to be comparable over 48 months. Table 2 shows the mean IOP and change from baseline in patients experiencing increased iris pigmentation (IIP) and those not experiencing increased iris pigmentation (NIIP).

5.2 Pharmacokinetic Properties

Latanoprost is an isopropyl ester prodrug which is inactive, but after hydrolysis to the acid of latanoprost, becomes biologically active.
Absorption and distribution. The prodrug is well absorbed through the cornea and all drug that enters the aqueous humour is hydrolysed during the passage through the cornea.
Studies in man indicate that the peak concentration in the aqueous humour is reached about two hours after topical administration. After topical application in monkeys latanoprost is distributed primarily in the anterior segment, the conjunctivae and the eye lids. Only minute quantities of the drug reach the posterior segment.
Following an ocular dose of latanoprost, 45% of latanoprost acid is absorbed systemically, with 90% being bound to plasma proteins.
Metabolism. There is practically no metabolism of the acid of latanoprost in the eye. The main metabolism occurs in the liver. Following intravenous administration in man, the half-life in plasma is 17 minutes.
Excretion. The main metabolites, the 1,2-dinor and 1,2,3,4-tetranor metabolites, exert no or only weak biological activity in animal studies and are excreted primarily in the urine.

5.3 Preclinical Safety Data

Genotoxicity. Latanoprost was not mutagenic in gene mutation assays in bacteria and mouse lymphoma L5178Y cells and was negative in studies of unscheduled DNA synthesis. Chromosome aberrations were observed with human lymphocytes in vitro but latanoprost did not induce micronucleus formation in vivo.
Carcinogenicity. Latanoprost was not carcinogenic in either rats or mice when administered by oral gavage at doses up to 170 micrograms/kg/day for 24 and 20 months respectively.
Animal toxicity. The ocular as well as systemic toxicity of latanoprost has been investigated in several animal species. Intravenous acute toxicity studies (2 mg/kg) and oral acute toxicity studies (50 mg/kg) in rats and mice resulted in no mortality. Latanoprost, 2-6 micrograms/kg bodyweight, administered intravenously to unanaesthetised monkeys have been shown to increase the respiration rate probably reflecting bronchoconstriction of short duration.
In animal studies latanoprost has not been found to have sensitising properties.
In the eye no significant toxic effects have been detected with doses of up to 100 micrograms/eye/day in rabbits or monkeys (clinical dose is approximately 1.5 micrograms/eye/day). In monkeys, however, latanoprost has been shown to induce increased pigmentation of the iris. The mechanism of increased pigmentation seems to be stimulation of melanin production in melanocytes of the iris with no proliferative changes observed. The change in iris colour may be permanent.
In chronic ocular toxicity studies, administration of latanoprost at 6 micrograms/eye/day has also been shown to induce increased palpebral fissure. This effect is reversible and occurs at doses above the clinical dose level. The effect has not been seen in humans.

6 Pharmaceutical Particulars

6.1 List of Excipients

The excipients in Xalaprost are benzalkonium chloride (as a preservative), dibasic sodium phosphate, hydrochloric acid, monobasic sodium phosphate monohydrate, sodium chloride, sodium hydroxide, water for injections.

6.2 Incompatibilities

In vitro studies have shown that precipitation occurs when eye drops containing thiomersal are mixed with latanoprost eye drops. If such drugs are used the eye drops should be administered with an interval of at least five minutes.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Before opening. Store at 2°C to 8°C. Protect from light. Do not freeze.
After opening. Store below 25°C. Protect from light. Do not freeze. Discard 4 weeks after opening.

6.5 Nature and Contents of Container

Container type: Bottle (LDPE).
Pack sizes: 1 x 2.5 mL (5 mL bottle).
Australian register of therapeutic goods (ARTG). AUST R 217151 - Xalaprost latanoprost 50 microgram/mL eye drops bottle.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking it to your local pharmacy.

6.7 Physicochemical Properties

Chemical structure.

Latanoprost is a viscous oil which is practically insoluble in water, freely soluble in ethanol, ethyl acetate, isopropanol, methanol, acetone and octanol, and very soluble in acetonitrile.
Sixty four isomers of latanoprost are possible, however, for Xalaprost it is purified as a single isomer.
Xalaprost is a sterile, isotonic solution, pH 6.7. Chemical name: isopropyl-(Z)-7[(1R,2R,3R,5S) 3,5-dihydroxy-2-[(3R)-3- hydroxy-5-phenyl-1-pentyl]cyclopentyl]-5-heptenoate.
Molecular formula: C₂₆H₄₀O₅.
Molecular weight: 432.58.
CAS number. 130209-82-4.

7 Medicine Schedule (Poisons Standard)

S4 (Prescription Only Medicine).

Date of First Approval

09 September 2014

Date of Revision

23 March 2023

Summary Table of Changes