Topical nonsteroidal anti-inflammatory drugs for ophthalmic use: a safety review

Oral versus topical diclofenac for pain prevention during panretinal photocoagulation

PURPOSE

To investigate the effect of pretreatment oral and topical diclofenac on pain reduction during panretinal laser photocoagulation (PRP) for proliferative diabetic retinopathy (PDR).

DESIGN

Prospective, randomized, double-masked, placebo-controlled clinical trial.

PARTICIPANTS AND CONTROLS

A total of 90 patients with PDR requiring PRP for the first time were assigned randomly to 1 of 3 study groups: oral diclofenac (n = 30), topical diclofenac (n = 31), or placebo (n = 29).

METHODS

Study medications were administrated before the first PRP treatment, and pain levels experienced during and 15 minutes after PRP were recorded on a visual analog scale (VAS). Pain levels during a second PRP session, performed on a later date with no pretreatment medications, also were recorded on a VAS.

MAIN OUTCOME MEASURES

The primary outcome measures were the mean VAS pain scores during the first PRP treatment. Secondary outcome measures were the mean VAS pain scores 15 minutes after the first PRP and during the second PRP, and reported side effects after the first PRP.

RESULTS

Mean VAS pain scores during the first PRP were: oral diclofenac, 25.7+/-19.9; topical diclofenac, 33.8+/-27.9; and placebo, 41.3+/-31.0. The pain score difference between oral diclofenac and placebo was both clinically significant (>or=13) and statistically significant (P = 0.02), whereas differences between oral and topical diclofenac (P = 0.20) and topical diclofenac and placebo (P = 0.33) were not. Multivariate regression analysis for age, gender, and total laser energy demonstrated lower pain levels for both oral diclofenac (P = 0.015) and topical diclofenac (P<0.0001) versus placebo, but no difference between oral and topical diclofenac (P = 0.67). For the first PRP, all 3 groups had lower mean pain scores at 15 minutes after treatment compared with during treatment (P<or=0.0003). Mean pain scores were higher during the second compared with the first PRP for the oral diclofenac (P = 0.02) and placebo (P = 0.05) groups. No significant rate difference for any side effect was found between groups.

CONCLUSIONS

When given in a single dose, oral diclofenac is an effective pretreatment analgesic agent for reducing the pain experienced during PRP for PDR.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Pathophysiology of cyclooxygenase inhibition in animal models

Cyclooxygenase (COX) catalyzes the conversion of arachidonic acid into prostaglandins (PGs), which play a significant role in health and disease in the gastrointestinal tract (GI) and in the renal, skeletal, and ocular systems. COX-1 is constitutively expressed and found in most normal tissues, whereas COX-2 can be expressed at low levels in normal tissues and is highly induced by pro-inflammatory mediators. Inhibitors of COX activity include: (1) conventional nonselective, nonsteroidal anti-inflammatory drugs (ns-NSAIDs) and (2) COX-2 selective nonsteroidal anti-inflammatory drugs (COX-2 s-NSAIDs). Inhibition of COX-1 often elicits GI toxicity in animals and humans. Therefore, COX-2 s-NSAIDs were developed to provide a selective COX-2 agent, while minimizing the attendant COX-1-mediated GI toxicities. Rats and dogs overpredict COX inhibition for renal effects such as renal handling of electrolytes in humans. COX inhibitors are shown to have both beneficial and detrimental effects, such as on healing of ligament or tendon tears, on the skeletal system in animal models. Certain ophthalmic conditions such as glaucoma and keratitis are associated with increased COX-2 expression, suggesting a potential role in their pathophysiology.

Polyoxyethylated nonionic surfactants and their applications in topical ocular drug delivery

Topical dosing of ophthalmic drugs to the eye is a widely accepted route of administration because of convenience, ease of use, and non-invasiveness. However, it has been well recognized that topical ocular delivery endures a low bioavailability due to the anatomical and physiological constraints of the eye which limit drug absorption from the pre-corneal surface. Nonionic surfactants as versatile functional agents in topical ocular drug delivery systems are uniquely suited to meet the challenges through their potential ability to increase bioavailability by increasing drug solubility, prolonging pre-corneal retention, and enhancing permeability. This review attempts to place in perspective the importance of polyoxyethylated nonionic surfactants in the design and development of topical ocular drug delivery systems by assessing their compatibility with common ophthalmic inactive ingredients, their impact on product stability, and their roles in facilitating ocular drugs to reach the target sites.

Canine and feline uveitis

The clinical signs of uveitis occur as a result of inflammation within the vascular coat of the eye, which causes breakdown of the blood-aqueous barrier and blood-retinal barrier. Many infectious and noninfectious causes can incite episodes of uveitis. Although a complete diagnostic evaluation is highly recommended to identify any underlying etiologic agent, many cases remain idiopathic in nature. The goals of therapy are preserving vision, minimizing pain, and halting inflammation.

Topical pranoprofen 0.1% is as effective anti-inflammatory and analgesic agent as diclofenac sodium 0.1% after strabismus surgery

To compare the anti-inflammatory and analgesic effects of topical pranoprofen 0.1% with diclofenac sodium 0.1% after strabismus surgery, 40 patients were prospectively randomized and assigned into 2 groups. Signs and symptoms of inflammation, as well as intraocular pressure (IOP) of patients, were evaluated at 1 day and 1 and 3 weeks following surgery. Both groups reported reduced inflammation and discomfort at 1 week, as compared to 1 day. There was no statistically significant difference in any measurement of postoperative inflammation (i.e., discomfort, chemosis, secretion, conjunctival hyperemia, and conjunctival gap size) between the 2 groups at any time. None of the patients developed an allergic reaction to the medications and IOP measurements were within the normal limits in both groups. Pranoprofen 0.1% was found to be as effective as diclofenac sodium 0.1% in reducing inflammation and pain after strabismus surgery. Pranoprofen could be used as a safe and effective anti-inflammatory alternative for the treatment of inflammation following strabismus surgery.

The role of NSAIDs in the management of postoperative ophthalmic inflammation

Recent advances in cataract surgery, such as phacoemulsification, small-incision surgery and advances in foldable intraocular lenses, have resulted in the decrease of physical trauma associated with cataract surgery. The decrease in the physical surgical trauma decreases the release of prostaglandins, which are the main players in postoperative ocular inflammation. However, postoperative inflammation continues to be a cause of patient discomfort, delayed recovery and, in some cases, suboptimal visual results. Left untreated, this inflammation might interfere with patients' rehabilitation and/or contribute to the development of other complications, such as cystoid macular oedema.NSAIDs are commercially available, in topical or systemic formulations, for the prophylaxis and treatment of ocular conditions. Topically applied NSAIDs are commonly used in the management and prevention of non-infectious ocular inflammation and cystoid macular oedema following cataract surgery. They are also used in the management of pain following refractive surgery and in the treatment of allergic conjunctivitis. Despite their chemical heterogeneity, all NSAIDs share the similar therapeutic property of inhibiting the cyclo-oxygenase enzyme. The appeal of using NSAIDs in the treatment of ocular inflammation hinges on the complications associated with corticosteroids, the other commonly used therapy for ophthalmic inflammation.

Effects of topical anti-inflammatory agents in a botulinum toxin B-induced mouse model of keratoconjunctivitis sicca

PURPOSE

The aim of this study was to compare the effects of topical nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroid, doxycycline, and artificial tears for the treatment of ocular surface damage in the Botulinum toxin B (BTX-B)-induced mouse model of dry eye.

METHODS

CBA/J mice were randomized into 2 experimental groups of 35 animals each. The control group received a transconjunctival injection of 0.05 mL of saline into the left lacrimal gland, and another group was injected with 0.05 mL of 20 milliunits BTX-B solution (SPSS, Inc., Chicago, IL). Three (3) days after intralacrimal gland injections, each group was equally randomized into 7 subgroups (n=5 each) to receive treatment unilaterally into their left eyes with topical artificial tears (0.5% carboxymethylcellulose sodium), 0.1% fluorometholone, 0.1% nepafenac, 0.4% ketorolac, 0.09% bromfenac, 0.1% diclofenac, or 0.025% doxycycline. Tear volume, ocular surface changes, and spontaneous blink rate were evaluated in each of the 14 experimental subgroups.

RESULTS

Topical fluorometholone, nepafenac, and doxycycline significantly improved corneal surface staining in the BTX-B-injected mice within 2 weeks of treatment. Topical ketorolac, diclofenac, and bromfenac, applied twice-daily, partially reduce corneal staining, and did so more slowly by the 4-week time point. In comparison, topical artificial tear-treated mice did not demonstrate significant improvement of the corneal surface at any time point. Aqueous tear production in the BTX-B-injected fluorometholone-treated group started to return to baseline level within 2 weeks, although not significantly. Meanwhile, BTX-B-injected mice treated with artificial tears, topical NSAIDs, and doxycycline still exhibited a reduction in tear production up to 4 weeks. No significant differences in blink rate between the control and study groups undergoing the various treatments were noted at all time points.

CONCLUSIONS

This study suggests the potential usefulness of topical NSAIDs, corticosteroid, and doxycycline for the clinical treatment of ocular surface epithelial disorders associated with dry eye.

Ketorolac during the induction phase of cyclosporin-A therapy

PURPOSE

The aim of this study was to determine if the concomitant use of ketorolac 0.4% and cyclosporin-A improves patient comfort during the induction phase in treating chronic dry eye disease.

METHODS

Patients (n = 52) with clinically diagnosed dry eye were randomized to receive either cyclosporin-A monotherapy twice-daily (BID) or a BID adjunctive regimen of ketorolac, followed by the instillation of cyclosporin-A 10 min later. Study visits were at baseline, week 2, and week 6. At each study visit, patients underwent an evaluation for corneal staining, Schirmer's scores, and tear break-up time tests. Patients were asked to rate ocular comfort on a 4-point scale and to complete the ocular surface disease index (OSDI). Changes from baseline readings were recorded at week-2 and week-6 visits, and final patient success on treatment regimen was evaluated at week 6.

RESULTS

After 6 weeks, the mean ocular comfort score of adjunctive patients improved 2.55 +/- 0.95 points, versus 1.53 +/- 0.91 points for monotherapy (P = 0.309). The adjunctive regimen provided significantly greater corneal staining reductions versus monotherapy, mean reduction in staining of 1.74 +/- 0.9, versus 1.27 +/- 0.56 (P = 0.044).

CONCLUSIONS

Concurrent ketorolac 0.4% use with cyclosporin-A significantly reduced corneal staining and increased comfort in the induction phase.

An update on the use of ophthalmic ketorolac tromethamine 0.4%

Ketorolac tromethamine 0.4% ophthalmic solution, a recent reformulation of the original ketorolac tromethamine 0.5% solution, is indicated for the reduction of ocular pain and burning/stinging following cataract and refractive surgery. Studies have demonstrated that ketorolac tromethamine 0.4% has equivalent efficacy to ketorolac tromethamine 0.5% in reducing postsurgical inflammation and controlling pain. Several studies have demonstrated that, as well as reducing pain and ocular inflammation, ketorolac tromethamine 0.4% effectively treats cystoid macular oedema, inhibits miosis and may prevent cystoid macular oedema when used both pre- and postoperatively. Ketorolac tromethamine 0.4% is a versatile agent and is effective when used as either monotherapy or as an adjunct therapy to steroids.

The influence of diclofenac ophthalmic solution on the intraocular pressure-lowering effect of topical 0.5% timolol and 0.005% latanoprost in primary open-angle glaucoma patients

The aim of this randomized, prospective, masked clinical study has been to verify the influence of a non-steroidal anti-inflammatory drug ophthalmic solution on intraocular pressure reduction induced by 0.5% timolol and 0.005% latanoprost eyedrops in patients affected by primary open-angle glaucoma. Thirty-two glaucomatous patients, compensated with 0.5% timolol, were randomized into two study groups (A and B). Timolol was continued for the first 2 weeks in all subjects. On the 15th day, in both groups timolol was replaced by latanoprost, and this regimen lasted up to the end of the follow-up (8 weeks). At the beginning of the 2nd week of the study, group A additionally started a 5-week therapy with topical 0.1% diclofenac; during the same period, group B received placebo eyedrops with identical modalities. Intraocular pressure was recorded at 7-day intervals during the first 7 weeks and at the 10th week. Non-steroidal anti-inflammatory drug and placebo did not modify the effect of timolol on intraocular pressure. In both groups, latanoprost induced a significant decrease in intraocular pressure. Diclofenac-treated patients exhibited a marked fall in intraocular pressure (p<0.01), whereas in placebo-treated patients, this diminution was less noticeable (p<0.05). After diclofenac withdrawal, in group A intraocular pressure significantly increased (p<0.01), remaining approximately at the same level up to the end of the study. In group B, at the same checks no significant variations in intraocular pressure occurred. In primary open-angle glaucoma patients, diclofenac significantly enhances the hypotensive effect of latanoprost, without influence on timolol efficacy. Because non-steroidal anti-inflammatory drugs are widely employed in medical practice, supplementary ophthalmologic checks should be scheduled during the co-administration of these compounds and prostaglandin analogues.

Potential Protective Effects of NSAIDs/ASA in Oxidatively Stressed Human Lens Epithelial Cells and Intact Mouse Lenses in Culture

PURPOSE

To study possible toxic effects of indomethacin, diclofenac, and celecoxib (NSAIDs) and acetylsalicylic acid (ASA) as well as potentially protective effects of these substances in oxidatively stressed human lens epithelial cells (HLEC) and in intact mouse lenses in culture.

METHODS

HLEC and mouse lenses were incubated with NSAIDs or ASA alone or in the presence of H2O2. To study apoptosis the cells were then either stained with Hoechst 33342 or assayed for caspase-3 activity. Mouse lenses were studied with respect to lens transparency.

RESULTS

Low concentrations of NSAIDs/ASA caused a significant protection against H2O2-induced apoptosis in HLEC whereas higher concentrations were toxic.

CONCLUSION

The protective effects of NSAIDs/ASA against oxidative damage are confined to a relatively small therapeutic window.

A clinical comparison of two different prednisolone acetate formulations in patients undergoing cataract surgery

PURPOSE

This study was conducted to evaluate the efficacy of two topical steroid prednisolone preparations (Econopred Plus 1%, prednisolone acetate 1%: EPP; Pred Fortedagger 1%, prednisolone acetate 1%: PF) in reducing postoperative inflammation in cataract patients.

METHODS

This was a 4 week, randomized, parallel-group, single-center, active-controlled study. One group of patients received postoperative topical EPP while the other group received postoperative topical PF. Both medications were dosed 4 times per day for 14 days and then BID until the container was empty. Both groups of patients received diclofenac sodium QID for 14 days and hydroxypropyl guar (HP-Guar, Systane) QID for 7 days then PRN (or as directed). The presence of corneal surface keratitis, anterior chamber cells and flare (scales 0-3 for keratitis, 0-5 for cells and 0-4 for flare; 0 = none) was evaluated by slit lamp biomicroscopy.

RESULTS

EPP produced significantly lower (P < 0.05) anterior chamber flare scores 14 days following surgery (mean +/- SD: 0.86 +/- 0.53) than PF (1.08 +/- 0.40). Otherwise, there were no differences observed between the 2 treatments with respect to keratitis, anterior chamber flare or cells at postop days 1, 7, or 28.

CONCLUSIONS

This comparative trial demonstrated that both formulations of prednisolone acetate 1% have similar efficacy in the treatment of postoperative ophthalmologic inflammation.

Emerging guidelines for use of NSAID therapy to optimize cataract surgery patient care

This analysis provides guidelines for the proper use of topical ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs), discusses their effect on inflammation, and their role in the prevention of cystoid macular edema (CME). A novel treatment strategy is presented for recommended topical ophthalmic NSAID dosing in patient populations based on risk factors for CME. The article reviews current topical ophthalmic NSAIDs, as well as a newest generation of pro-drug NSAIDs. In addition, combination therapy of NSAIDs and corticosteroids are discussed, along with a general review of therapeutic guidelines for dosing regimens, and benefits and risks of therapy. The goal of this analysis is to provide a suggested therapeutic regimen with topical NSAIDs to assist in achieving optimal clinical and functional outcomes.

Nonsteroidal anti-inflammatory drugs in veterinary ophthalmology

Uveitis is a common sequela to many ocular diseases. Primary treatment goals for uveitis should be to halt inflammation, prevent or control complications caused by inflammation, relieve pain, and preserve vision. Systemic and topical NSAIDs are essential components of the pharmaceutic armamentarium currently employed in the management of ocular inflammation by general practitioners and veterinary ophthalmologists worldwide. NSAIDs effectively prevent intraoperative miosis; control postoperative pain and inflammation after intraocular procedures, thus optimizing surgical outcome; control symptoms of allergic conjunctivitis;alleviate pain from various causes of uveitis; and circumvent some of the unwanted side effects that occur with corticosteroid treatment. Systemic NSAID therapy is necessary to treat posterior uveitis, because therapeutic concentrations cannot be attained in the retina and choroid with topical administration alone, and is warranted when diseases, such as diabetes mellitus or systemic infection, preclude the use of systemic corticosteroids. Risk factors have been identified with systemic and topical administration of NSAIDs. In general, ophthalmic NSAIDs may be used safely with other ophthalmic pharmaceutics; however, concurrent use of drugs known to affect the corneal epithelium adversely, such as gentamicin, may lead to increased corneal penetration of the NSAID. The concurrent use of NSAIDs with topical corticosteroids in the face of significant preexisting corneal inflammation has been identified as a risk factor in precipitating corneal erosions and melts in people and should be undertaken with caution[8]. Clinicians should remain vigilant in their screening of ophthalmic and systemic complications secondary to drug therapy and educate owners accordingly. If a sudden increase in patient ocular pain (as manifested by an increase in blepharospasm, photophobia, ocular discharge, or rubbing)is noted, owners should be instructed to contact their veterinarian promptly.

COX-2 lack of function in hypoxia-induced ocular surface inflammation

Injury to the ocular surface increases corneal epithelial production of cyclooxygenase (COX)-derived eicosanoids but this increase correlates poorly to the inflammatory sequelae. Moreover, corticosteroids are effective in treatment of this inflammation but NSAIDs are not. The discovery of COX-2 that is differentially affected by common NSAIDs reopened the question of the role of prostaglandins in ocular surface inflammation. We examined the presence and inducibility of COX-2 in the corneal epithelium following hypoxia-induced injury in vivo and in vitro. COX-2, but not COX-1, protein levels markedly increased following hypoxia. Use of the selective COX-2 inhibitor, NS-398, indicated that COX activity in hypoxic corneas or cells is essentially that of COX-2; in control cells, both COX-1 and COX-2 contributed equally to the production of PGE2. COX-2 protein overexpression induced by hypoxia was not associated with a parallel increase in PGE2 accumulation but the enzyme regained full catalytic activity when cells were re-exposed to normoxia in the presence of heme and arachidonic acid. Decreases in the levels of oxygen and heme, essential substrates/cofactors for COX catalytic activity, contributed to a diminished prostanoid production during hypoxia. These results suggest that in hypoxic injury, molecules other than COX-derived prostanoids play a major pro-inflammatory role. Furthermore, this study provides an explanation for the ineffectiveness of classical NSAIDs in the treatment of hypoxia-related ocular surface inflammation.

An in vivo study comparing the ocular absorption of levofloxacin and ciprofloxacin prior to phacoemulsification

PURPOSE

To compare aqueous humor concentrations of levofloxacin vs ciprofloxacin when used as prophylactic medications before phacoemulsification.

DESIGN

Patients (n = 93) were randomly assigned to receive either 0.5% levofloxacin (Quixin) or 0.3% ciprofloxacin (Ciloxan) using one of the following dosing regimens: (A) 1 to 2 drops four times a day for 2 days preoperatively; (B) 5 doses (1 to 2 drops) delivered every 10 minutes in the hour immediately preceding surgery; or (C) the combination of A and B.

METHODS

Aqueous samples (0.1 ml) were obtained immediately before surgery, and drug concentrations were measured using high performance liquid chromatography/mass spectrometry.

RESULTS

The mean concentration of levofloxacin in the aqueous humor was significantly greater than that of ciprofloxacin in all treatment groups (P <.001): 284.8 vs 67.4 microg/ml (regimen A); 1,135.6 vs 185.6 microg/ml (regimen B); and 1,618.6 vs 241.5 (regimen C). Dosing regimen B delivered significantly more drug to the aqueous humor than regimen A for both levofloxacin (P < or =.001) and ciprofloxacin (P =.004). Dosing regimen C delivered significantly more drug to the aqueous humor than regimen B for levofloxacin (P =.05) but not for ciprofloxacin (P =.384).

CONCLUSIONS

Although the concentration of active drug in levofloxacin is approximately 1.7-fold higher than that in ciprofloxacin, the aqueous concentration of levofloxacin after topical administration was four to seven times greater than ciprofloxacin; these differences were statistically significant. With dosing regimens B and C, levofloxacin concentrations in the aqueous humor were above the MIC90 for most common ocular pathogens, including Staphylococcus and Streptococcus species. Ciprofloxacin did not reach such concentrations in any treatment group.