Latanoprost, sold under the brand name Xalatan among others, is a medication used to treat increased pressure inside the eye. This includes

ocular hypertension Ocular hypertension is the presence of elevated fluid pressure inside the eye (intraocular pressure), usually with no optic nerve damage or visual field loss. For most individuals, the normal range of intraocular pressure is between 10 mmHg and 2 ...

and

open angle glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye rem ...

. It is applied as

eye drops Eye drops or eyedrops are liquid drops applied directly to the surface of the eye usually in small amounts such as a single drop or a few drops. Eye drops usually contain saline to match the salinity of the eye. Drops containing only saline ...

to the eyes. Onset of effects is usually within four hours, and they last for up to a day. Common side effects include

blurry vision Blurred vision is an ocular symptom where vision becomes less precise and there is added difficulty to resolve fine details. Temporary blurred vision may involve dry eyes, eye infections, alcohol poisoning, hypoglycemia, or low blood pressure. ...

, redness of the eye, itchiness, and darkening of the

iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...

. Latanoprost is in the prostaglandin analogue family of medications. It works by increasing the outflow of aqueous fluid from the eyes through the uveoscleral tract. Latanoprost was approved for medical use in the United States in 1996. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...

. Latanoprost is available as a generic medication. In 2020, it was the 77th most commonly prescribed medication in the United States with more than 9million prescriptions. It is available as a combination with netarsudil and with timolol.

Medical uses

Open-angle glaucoma

In people with

(

intraocular pressure Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. Most tonometers are calibrated t ...

(IOP) ≥21

mm Hg A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high, and currently defined as exactly pascals. It is denoted mmHg or mm Hg. Although not an ...

) including

open-angle glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye rem ...

, treatment with latanoprost reduced IOP levels by 22 to 39% over 1 to 12 months’ treatment. Latanoprost was more effective than timolol 0.5% twice daily in 3 of 4 large (n = 163 to 267) randomised, double-blind trials. Latanoprost demonstrated a stable long-term IOP-lowering effect in 1- or 2-year continuations of these trials, with no sign of diminishing effect during prolonged treatment.

Meta-analysis A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting me ...

suggests that latanoprost is more effective than timolol in lowering intraocular pressure (IOP). However, it often causes

pigmentation. While current evidence suggests that this pigmentation is benign, careful lifetime evaluation of patients is still justified.

Closed-angle glaucoma

Patients who had elevated IOP despite iridotomy and/or iridectomy (including patients of Asian descent), latanoprost was significantly more effective than timolol in two double-blind, monotherapy trials (8.2 and 8.8 mm Hg vs 5.2 and 5.7 mm Hg for latanoprost vs timolol at 12 and 2 weeks, respectively).

Adverse effects

Listed from most to least common: * > 5–15%: blurred vision, burning and stinging, conjunctival

hyperemia Hyperaemia (also hyperemia) is the increase of blood flow to different tissues in the body. It can have medical implications but is also a regulatory response, allowing change in blood supply to different tissues through vasodilation. Clinically, ...

, foreign body sensation, itching, increased (brown) pigmentation of the iris (causing heterochromia), punctate epithelial keratopathy * 4%: cold or upper respiratory tract infections, flu-like syndrome * 1–4%: dry eyes, excessive tearing, eye pain, lid crusting, lid edema, lid

erythema Erythema (from the Greek , meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not asso ...

(hyperemia), lid pain,

photophobia Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of ...

* 1–2%: chest pain, allergic skin reactions,

arthralgia Arthralgia (from Greek ''arthro-'', joint + ''-algos'', pain) literally means ''joint pain''. Specifically, arthralgia is a symptom of injury, infection, illness (in particular arthritis), or an allergic reaction to medication. According to MeSH, ...

, back pain, myalgia * < 1 % (only severe or life-threatening effects): asthma, herpes

keratitis Keratitis is a condition in which the eye's cornea, the clear dome on the front surface of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves any of the following symptoms: pain, impaired e ...

, iritis, keratitis, retinal artery

embolus An embolus (; plural emboli; from the Greek ἔμβολος "wedge", "plug") is an unattached mass that travels through the bloodstream and is capable of creating blockages. When an embolus occludes a blood vessel, it is called an embolism or emb ...

, retinal detachment,

toxic epidermal necrolysis Toxic epidermal necrolysis (TEN) is a type of severe skin reaction. Together with Stevens–Johnson syndrome (SJS) it forms a spectrum of disease, with TEN being more severe. Early symptoms include fever and flu-like symptoms. A few days later ...

uveitis Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and in ...

, vitreous hemorrhage from

diabetic retinopathy Diabetic retinopathy (also known as diabetic eye disease), is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries. Diabetic retinopathy affects up to 80 perc ...

*A single case report links latanoprost use to the progression of keratoconus. Research suggests that wiping the eye with an absorbent pad after the administration of eye drops can result in shorter eyelashes and a lesser chance of hyperpigmentation in the eyelid, compared to not wiping off excess fluid.

Pregnancy

Use in pregnant women is limited due to high incidence of abortion shown in animal experiments. Because of this, latanoprost is classified as risk factor C (adverse events were observed in animal reproduction studies at maternally toxic doses) according to United States

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

's use-in-pregnancy ratings. Drug excretion in breast milk is unknown.

Interactions

Interactions are similar to other prostaglandin analogs. Paradoxically, the concomitant use of latanoprost and

bimatoprost Bimatoprost, sold under the brand name Lumigan among others, is a medication used to treat high pressure inside the eye including glaucoma. Specifically it is used for open angle glaucoma when other agents are not sufficient. It may also be used ...

or other prostaglandins may result in increased intraocular pressure.

Non-steroidal anti-inflammatory drug Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...

s (NSAIDs) can reduce or increase the effect of latanoprost.Latanoprost .

Pharmacology

Mechanism of action

Like tafluprost and

travoprost Travoprost, sold under the brand name Travatan among others, is a medication used to treat high pressure inside the eye including glaucoma. Specifically it is used for open angle glaucoma when other agents are not sufficient. It is used as an eye ...

, latanoprost is an

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...

prodrug that is activated to the free acid in the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...

. Also like the related drugs, latanoprost acid is an analog of prostaglandin F_2α that acts as a selective agonist at the

prostaglandin F receptor Prostaglandin F receptor (FP) is a receptor belonging to the prostaglandin (PG) group of receptors. FP binds to and mediates the biological actions of Prostaglandin F2α (PGF2α). It is encoded in humans by the ''PTGFR'' gene. Gene The ''PTG ...

. Prostaglandins increase the sclera's permeability to aqueous fluid. So, an increase in prostaglandin activity increases outflow of aqueous fluid thus lowering intraocular pressure.

Pharmacokinetics

Latanoprost is absorbed well through the cornea and completely hydrolysed to the active latanoprost acid. Highest concentrations of the acid in the aqueous humour are reached two hours after application, lowering of intraocular pressure starts after 3 to 4 hours, the highest effect is found after 8 to 12 hours, and its action lasts at least 24 hours. When latanoprost acid reaches the circulation, it is quickly metabolised in the liver by

beta oxidation In biochemistry and metabolism, beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cyc ...

to 1,2-dinor- and 1,2,3,4-tetranor-latanoprost acid; blood plasma half life is only 17 minutes. The metabolites are mainly excreted via the kidney. The activation and deactivation pathway is analogous to the one of tafluprost (at least up to the tetranor-metabolite); compare Tafluprost#Pharmacokinetics. Latanoprost metabolism

Chemistry

Stability

Latanoprost exhibits

thermal A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

and solar instability. The concentration of latanoprost stored at 50 °C will decrease by 10% every 8.25 days. When stored at 70 °C the concentration will decrease by 10% every 1.32 days. Ultraviolet light, for example in sunlight, causes rapid degradation of latanoprost.

Society and culture

The brand Xalatan is manufactured by

Pfizer Pfizer Inc. ( ) is an American multinational pharmaceutical and biotechnology corporation headquartered on 42nd Street in Manhattan, New York City. The company was established in 1849 in New York by two German entrepreneurs, Charles Pfizer ...

Cosmetic use

* Lengthening and thickening of the eyelashes (used, like

, in the cosmetic industry as eyelash growth enhancers). * There is one small study that found benefit in androgenic alopecia.

References

External links

* {{Portal bar, Medicine Alkene derivatives Carboxylate esters Cyclopropanes Hair loss medications Isopropyl esters Ophthalmology drugs Pfizer brands Prostaglandins Triols World Health Organization essential medicines Wikipedia medicine articles ready to translate