Latanoprost administration

The ocular hypotensive lipids in typical ophthalmology practice are considered first-line alternatives to topical P-blockers because of their superior efficacy and safety profiles. Many clinicians may choose to use the ocular hypotensive lipids as first-line agents, especially in patients that have an initial requirement to lower IOP by more than 25%, or in patients that have relative or absolute contraindications to topical P-blockers. However, latanoprost is currently the only ocular hypotensive lipid drug that has a Food and Drug Administration (FDA) indication for first-line therapy. Bimatoprost and travoprost are indicated by the FDA for patients who are intolerant of other IOP-lowering therapy or insufficiently responsive to another IOP-lowering medication.10,38... 

BIMATOPROST, LATANOPROST, TRAVOPROST The recommended dosage is 1 drop in the affected eye(s) once daily in the evening. Do not exceed once-daily dosage because it has been shown that more frequent administration may decrease the lOP-lowering effect. 

Contact lenses Remove contact lenses prior to the administration of latanoprost, and reinsert 15 minutes after administration. 

Pharmacokinetics Absorbed through the cornea where the isopropyl esterprodrug is hydrolyzed to acid form to become biologically active. Highly lipophilic. The acid of latanoprost can be measured in the aqueous humor during the first 4 hours and in the plasma only during the first hour after local administration. In cornea, latanoprost is hydrolyzed to the biologically active acid. Metabolized in liver if it reaches systemic circulation. Metabolized to 1,2-dinor metabolite and 1,2,3,4-tetranor metabolite. Primarily eliminated by the kidneys. Half-life 17 min. 

Krohn J, Hove VK. Iris cyst associated with topical administration of latanoprost. Am J Ophthalmol 1999 127(1) 91-3. 

Lai IC, Kuo MT, Teng IMC. Iris pigment epithelial cyst induced by topical administration of latanoprost. Br J Ophthalmol 2003 87 366. 

How does latanoprost work in the treatment of glaucoma Discuss the range of drugs and route of administration that can be used to treat this patient s glaucoma. 

As demonstrated with fluorophotometry, timolol acts predominantly by decreasing the production of aqueous humor and does not significantly alter facility of outflow. Most studies support the view that both short-term and long-term administration of timolol do not alter optic nerve head circulation or produce retrobulbar hemodynamic changes. The ocular hypotensive effect of timolol is additive to most other therapies, including outflow agents (e.g., pilocarpine) and inflow agents (e.g., dorzolamide, brinzolamide, apraclonidine, and brimonidine). When added to latanoprost, timolol and most other P-blockers further reduce lOP approximately 2 mm Hg. This reduction is less than that attained by topical CAIs such as dorzolamide (Table 10-2). 

The author commented that systemic absorption occurred for the most part through the mucous membranes of the nose and throat, since the sweating was less severe when the boy s lacrymal points were compressed for 10 minutes after the administration of latanoprost. 

Stjernschantz et al. later developed latanoprost [22], which has potent IOP-reducing effects with topical administration once daily in the evening. Compared with a representative (3-blocker, timolol, it demonstrated superior efficacy in clinical studies in reducing IOP by approximately 27-34% from baseline. Latanoprost is the FP receptor agonist most widely used worldwide as an anti-glaucoma drug. 

Another study aimed to evaluate and compare the effect of tafluprost, latanoprost, and travoprost on optic nerve head (ONH) blood flow in rabbits [42], A quantitative index of blood flow, squared blur rate (SBR), was determined with the laser speckle method, when 50pl of 0.0015% tafluprost, 0.005% latanoprost, or 0.004% travoprost were topically administrated once a daily for 28 days. After 28 days administration of tafluprost, latanoprost, and travoprost, the trough SBR values became 111.9 3.9%, 107.2 + 4.3% and 106.7 3.5%, respectively, compared with the value before administration. Sixty minutes after final administration on day 28, the SBR value with tafluprost, latanoprost, and travoprost become 116.1 + 3.5%, 106.1 3.0%, and 104.2 3.7%, respectively, compared with the value before administration. These results indicate that topical administrations of these compounds stably increase the ONH blood flow in rabbits. The magnitude of increase in ONH blood flow produced by tafluprost was greater than that of latanoprost or travoprost. 

Hyaluronan-induced hypertension in rats was significantly decreased by the application of one drop of brimonidine (0.2%), latanoprost (0.005%), or timolol (0.5%), suggesting that intracameral administration of hyaluronan could be a model for ocular hypertension (127). 

Sjoquist, B. Tajallaei, S. Stjernschantz, J. Pharmacokinetics of latanoprost in the cynomolgus monkey. 1st communication single intravenous, oral or topical administration on the eye, Arzneimittelforschung, 1999, 49, 225-233. 

Sensory systems A case series of three patients who presented with periocular changes in the treated eye following chronic administration of unilateral latanoprost 0.005% has appeared published [53 ]. The clinical changes included worsening of dermatochalasis, deepening of superior sulcus and hollowness of the lid. This similar observation was previously described in usage of bimatoprost 0.03% and travoprost 0.004%. However this has not been reported in latanoprost instillation. Therefore, patients should be made aware of these potential side effects. 

Ung T, Currie ZI. Periocular changes following long-term administration of latanoprost 0.005%. Ophthal Plast Reconstr Surg 2012 28(2) e42-4. Dasari P, Sagfli H, Udupi G. Unusual complication of vaginal delivery is misoprostal the cause BMJ Case Rep 2012 Oct 9 2012. http // dx.doi.org/10.1136/bcr-2012-007005. pii bcr2012007005. 

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