Evaluation of 0.4% ketorolac tromethamine ophthalmic solution versus 0.5% ketorolac tromethamine ophthalmic solution after phacoemulsification and intraocular lens implantation

Fill levels, cost comparisons, and expulsion force requirements of commonly used topical ophthalmic nonsteroidal anti-inflammatory drugs

PURPOSE

To determine volume fill levels, estimated costs, and force expulsion requirements per bottle of topical ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs) commonly perioperatively in the United States.

SETTING

Tertiary care academic medical center.

DESIGN

Prospective laboratory investigation.

METHODS

8 commercially available NSAIDs (3 branded, 5 generic) were tested: branded bromfenac 0.07%, generic bromfenac 0.09%, diclofenac 0.1%, flurbiprofen 0.03%, generic ketorolac 0.5%, branded ketorolac 0.5%, ketorolac 0.47%, and branded nepafenac 0.3%. 10 bottles of each medication were tested, with an additional bottle tested for expulsion force requirements. A double-blinded method was used to measure the actual bottle fill volume and number of drops per bottle. The total cost per drop was calculated using published cash prices. Force requirements were measured using a customized force gauge apparatus. Formulations were compared using the Kruskal-Wallis test, followed by pairwise comparisons with the Dwass, Steel, Critchlow-Fligner Method.

RESULTS

2 branded NSAIDs (bromfenac and nepafenac) had slightly lower-than-sticker volumes while generics other than ketorolac had higher-than-sticker volumes. Diclofenac and branded bromfenac had the highest and lowest adjusted number of drops respectively. Generic bromfenac and generic ketorolac had the highest and lowest adjusted volume compared with sticker volume respectively. Branded bromfenac was the most expensive medication, while generic diclofenac was the least expensive. Force expulsion requirements varied significantly among generic and branded NSAIDs.

CONCLUSIONS

Volume fill levels, patient-incurred costs, and expulsion force requirements per bottle of topical NSAID medications vary significantly. Surgeons may wish to consider these factors when deciding how best to use these medications perioperatively.

Nanocuboidal-shaped zirconium based metal organic framework for the enhanced adsorptive removal of nonsteroidal anti-inflammatory drug, ketorolac tromethamine, from aqueous phase

Nanocuboidal-shaped zirconium based metal organic framework (UiO-66) was synthesized and used for enhanced adsorptive removal (729.92 mg g⁻¹) of ketorolac tromethamine drug.

Recovery after cataract surgery

Cataract surgery is the most common ophthalmological surgical procedure, and it is predicted that the number of surgeries will increase significantly in the future. However, little is known about the recovery after surgery. The first aim of this study was to evaluate the prevalence, severity and duration of pain and other ocular discomfort symptoms experienced after cataract surgery. The other objectives were to identify the factors associated with lower postoperative patient satisfaction and to measure the effect of cataract surgery on patients' health-related quality of life (HRQoL) and visual function in everyday life. The study design was a prospective follow-up study. The course of the recovery and the presence of ocular symptoms were evaluated by interviewing the patients via a questionnaire at 1 day, 1 week, 6 weeks and one year after surgery The visual functioning in everyday life was measured with Visual Functioning Index VF-7 and Catquest-9SF-questionnaires and furthermore the HRQoL was measured with the 15D-instrument before surgery and at 12 months after surgery. The patients returned the questionnaires by mail and were interviewed in the hospital on the day of the surgery. The same patients filled-in all the questionnaires. The patient reports were used to collect the data on medical history. A total of 303 patients were approached at Kuopio University Hospital in 2010-2011 and of these 196 patients were eligible and willing to participate, with postoperative data being available from 186 (95%) patients. A systematic review article was included in the study procedure and it revealed the wide range in the reported incidence of postoperative ocular pain. Some of the identified randomized controlled studies reported no or only minor pain whereas in some studies significant pain or pain lasting for several weeks has been described in more than 50% of the study patients. In the present study setting, pain was reported by 34% during the first postoperative hours and by approximately 10% of patients during the first six weeks after surgery. During the early recovery in the hospital, only a minority of the patients reporting pain were provided with pain medication. The ocular discomfort symptoms such as itchiness, burning, foreign-body sensation and tearing were common both before (54%) and after surgery (38-52%). These symptoms can also be described as painful symptoms and are often difficult to distinguish from ocular pain. The symptoms are also typical of ocular surface disease, and some patients may benefit from the postoperative administration of tear substitutes. The patients reporting postoperative ocular symptoms were less satisfied with the treatment outcome at 12 months after surgery (p = 0.001) compared to the patients who experienced no symptoms. Those patients reporting less disability in visual functioning before surgery were more satisfied than patients with more reported disability. The HRQoL improved significantly after cataract surgery (p = 0.002). However, when compared to an age-and gender-standardized control population, in cataract subjects the HRQoL remained slightly worse both before and at 12 months after surgery.

Efficacy and vitreous levels of topical NSAIDs

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed medications and are routinely used for their analgesic, antipyretic, and anti-inflammatory properties. Because of their potent cyclooxygenase-inhibitory activity, they can inhibit pro-inflammatory prostaglandin synthesis, leading to complex inflammatory cascades. NSAIDs have been broadly used systemically for many decades and have recently become commercially available in the form of topical ophthalmic formulations. NSAIDs are weak acids with pKa values mostly between 3.5 and 4.5 and are poorly water-soluble. New, aqueous ophthalmic solutions of NSAIDs that afford better tissue penetration have recently been developed. In ophthalmological practice, topical NSAIDs are mostly used to stabilize pupillary dilation during intraocular surgery, manage postoperative pain and inflammation, and treat pseudophakic cystoid macular edema.

AREAS COVERED

This review focuses on the vitreous penetration of topical NSAIDs and their potential clinical applications in the treatment of retinal diseases.

EXPERT OPINION

A growing body of evidence suggests that NSAIDs may be beneficial in the treatment of age-related macular degeneration, diabetic retinopathy, and ocular tumors. Recent studies from our group and other authors have shown that the vitreous levels of NSAID exceed the median inhibitory concentration, which can significantly decrease vitreous PGE2 levels.

Comparing the Efficacy of Ophthalmic NSAIDs in Common Indications

Objective: To review the commercially available ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs), identify opportunities for therapeutic substitutions within and outside of their Food and Drug Administration (FDA)-approved indications, and identify clinically superior drugs within the class for specific indications. Data Source: A PubMed search (1992 through January 2014) was performed on the terms diclofenac, ketorolac, flurbiprofen, bromfenac, and nepafenac. Study Selection and Data Extraction: Clinical trials, meta-analyses, and review articles were evaluated if they were written in English and pertained to human subjects. Studies were excluded if they were in vitro studies, solely evaluated pharmacokinetic or pharmacodynamic properties, did not relate to the topical ophthalmic route, did not evaluate the FDA-approved indications of any available ophthalmic NSAID, or compared a reviewed drug with a nonreviewed drug (without placebo comparison). Data Synthesis: A total of 67 articles met the criteria for evaluation. Article quality, study design, and dosing of the medications were assessed to determine the clinical applicability of the results. The quality of the article was determined using the Oxford Centre for Evidence-based Medicine Levels of Evidence 1. Conclusions: Many formulations of the 5 reviewed NSAIDs have been studied across the 4 primary indications. These indications are (1) pain and inflammation associated with cataract surgery, (2) pain associated with corneal refractive surgery, (3) inhibition of intraoperative miosis, and (4) seasonal allergic conjunctivitis. Several studies have directly compared drugs within this class and have identified instances in which certain selections are therapeutically superior or equivalent to another. This information provides practitioners with guidance in selecting an optimal medication.

Prostaglandin E2 inhibition of ketorolac 0.45%, bromfenac 0.09%, and nepafenac 0.1% in patients undergoing phacoemulsification

INTRODUCTION

We compared the prostaglandin E(2) (PGE(2)) inhibition of three topical nonsteroidal antiinflammatory drugs (NSAIDs): ketorolac 0.45%, bromfenac 0.09%, and nepafenac 0.1% at peak dosing levels in patients previously scheduled to undergo phacoemulsification.

METHODS

This was a single-center, double-masked observational study of 121 patients randomized to one of three NSAID treatment arms. Patients were instructed to take the NSAID per on-label dosing (twice daily [b.i.d.] for ketorolac 0.45% and bromfenac 0.09%, three times a day [t.i.d.] for nepafenac 0.1%) for 1 day before surgery, and were to instill one drop the morning of surgery. Each patient received an additional four doses 1 hour prior to undergoing phacoemulsification. After completion of the paracentesis site with a super blade, aqueous humor (0.15 mL) was collected through the peripheral clear cornea with a 30 G needle attached to a tuberculin (TB) syringe. Aqueous humor samples were stored at -40°C prior to analysis, and diluted 1:10 with diluent. Assays were conducted on multiple plates in duplicate (seven standards per plate).

RESULTS

The mean (±SD) PGE(2) concentrations were 224.8±164.87 pg/mL for ketorolac 0.45% (n=42), 288.7±226.05 pg/mL for bromfenac 0.09% (n=41), and 320.4±205.6 pg/mL for nepafenac 0.1% (n=38). The difference between ketorolac 0.45% and nepafenac 0.1% was statistically significant (P=0.025). The difference between bromfenac 0.09% and nepafenac 0.1% was not significantly different (P=0.516).

CONCLUSIONS

Ketorolac 0.45% achieved the greatest inhibition of PGE(2) compared to nepafenac 0.1% and bromfenac 0.09%. Ketorolac 0.45% may be more efficacious at controlling inflammation at the time of cataract surgery versus nepafenac 0.1% and bromfenac 0.09%.

Critical appraisal of ophthalmic ketorolac in treatment of pain and inflammation following cataract surgery

Background:

The purpose of this review was to provide a critical appraisal of the literature supporting the efficacy of ophthalmic ketorolac (Acuvail^®) in the treatment of pain and inflammation after cataract surgery.

Methods:

Literature search and expert opinion of the authors.

Results:

Recent studies indicate greater intraocular drug levels in the anterior chamber and iris-ciliary body after topical application of Acuvail in comparison with older formulations of ketorolac. A large randomized, multicenter, placebo-controlled study demonstrated significantly less inflammation and pain after cataract surgery using Acuvail.

Conclusion:

Acuvail appears to be effective in reducing post-cataract surgery pain and inflammation.

Ocular pharmacokinetics of 0.45% ketorolac tromethamine

Purpose

A new carboxymethylcellulose (CMC)-containing ophthalmic formulation of 0.45% ketorolac, pH 6.8 (Acuvail^®) was recently developed for treatment of inflammation and pain after cataract surgery. This study compared pharmacokinetics of the new formulation with that of a prior formulation, 0.4% ketorolac, pH 7.4 (Acular LS^®).

Methods

Ketorolac formulations were administered bilaterally (35 μL) to female New Zealand White rabbits. Samples from aqueous humor and iris-ciliary body were collected at multiple time points, and ketorolac was quantified using liquid chromatography-tandem mass spectrometry.

Results

In aqueous humor, the peak concentration (C_max) and area under the concentration-time curve (AUC_0–τ) of ketorolac were, respectively, 389 ng/mL and 939 ng·h/mL following administration of the CMC-containing 0.45% ketorolac, pH 6.8, and 211 ng/mL and 465 ng·hr/mL following administration of the 0.4% ketorolac, pH 7.4. In iris-ciliary body, C_max and AUC_0–τ of ketorolac were, respectively 450 ng/g and 2040 ng·h/g after administration of the CMC-containing 0.45% ketorolac, pH 6.8, and 216 ng/g and 699 ng·h/g after administration of the 0.4% ketorolac, pH 7.4. PK simulations predicted an AUC_0–τ of 2910 ng·h/g for twice daily, CMC-containing 0.45% ketorolac, pH 6.8, compared to 725 ng·h/g for 4 times daily, 0.4% ketorolac, pH 7.4.

Conclusions

The CMC-containing formulation of 0.45% ketorolac, pH 6.8, increased ketorolac bioavailability by 2-fold in aqueous humor and by 3-fold in iris-ciliary body in comparison to the 0.4% ketorolac, pH 7.4, allowing a reduced dosing schedule from 4 times daily to twice daily.

Nonsteroidal anti-inflammatory drugs in ophthalmology

Nonsteroidal anti-inflammatory drugs (NSAIDs) are increasingly employed in ophthalmology to reduce miosis and inflammation, manage scleritis, and prevent and treat cystoid macular edema associated with cataract surgery. In addition, they may decrease postoperative pain and photophobia associated with refractive surgery and may reduce the itching associated with allergic conjunctivitis. In recent years, the U.S. Food and Drug Administration has approved new topical NSAIDs, and previously approved NSAIDs have been reformulated. These additions and changes result in different pharmacokinetics and dosing intervals, which may offer therapeutic advantages. For example, therapeutic effects on diabetic retinopathy and age-related macular degeneration may now be achievable. We provide an updated review on NSAIDs and a summary of their current uses in ophthalmology with attention to potential future applications.

Aqueous prostaglandin E(2) of cataract patients at trough ketorolac and bromfenac levels after 2 days dosing

INTRODUCTION

Ketorolac 0.4% administered four times daily (q.i.d.) has long been used safely and effectively for the alleviation of ocular inflamation and pain and the prevention of intraoperative miosis in patients undergoing cataract surgery. Bromfenac ophthalmic solution 0.09% was recently developed as an ocular anti-inflammatory drug with a twice-daily (b.i.d.) dosing regimen. This study was designed to evaluate if b.i.d. dosing with bromfenac 0.09%, in comparison with q.i.d. dosing with ketorolac 0.4%, provides adequate trough nonsteroidal anti-inflammatory drug levels that were effective enough to reduce aqueous prostaglandin (PG) E(2) levels of patients after cataract surgery toward the end of its dosing cycle.

METHODS

In this single-center, investigator-masked trial, patients undergoing cataract surgery were randomized to receive either ketorolac 0.4% q.i.d. or bromfenac 0.09% b.i.d. for 2 days preoperatively. Aqueous humor was collected at the start of surgery 6 hours after the last dose of ketorolac 0.4% and 12 hours after the last dose of bromfenac 0.09%. Aqueous PGE(2) levels and drug concentrations were evaluated by a competitive enzyme immunoassay and reverse-phase HPLC-mass spectroscopy, respectively.

RESULTS

A total of 61 patients received ketorolac 0.4% (n=30) or bromfenac 0.09% (n=31). The mean (+/-SD) aqueous PGE(2) level was 285.6+/-141.9 pg/mL in patients treated with ketorolac 0.4% and 386.2+/-131.0 pg/mL in patients treated with bromfenac 0.09% (P=0.006). The mean (+/-SD) aqueous concentrations of ketorolac and bromfenac were 83.6+/-73.8 ng/mL and 9.2+/-6.6 ng/mL, respectively (P<0.001).

CONCLUSIONS

Ketorolac 0.4% maintained significantly higher aqueous concentrations and lowered aqueous PGE(2) levels significantly more than bromfenac 0.09% at trough levels. Ketorolac 0.4% administered q.i.d. may provide a more sustained control of intraocular inflammation and pain than bromfenac 0.09% administered b.i.d.

Topical ocular delivery of NSAIDs

In ocular tissue, arachidonic acid is metabolized by cyclooxygenase to prostaglandins which are the most important lipid derived mediators of inflammation. Presently nonsteroidal anti-inflammatory drugs (NSAIDs) which are cyclooxygenase (COX) inhibitors are being used for the treatment of inflammatory disorders. NSAIDs used in ophthalmology, topically, are salicylic-, indole acetic-, aryl acetic-, aryl propionic- and enolic acid derivatives. NSAIDs are weak acids with pKa mostly between 3.5 and 4.5, and are poorly soluble in water. Aqueous ophthalmic solutions of NSAIDs have been made using sodium, potassium, tromethamine and lysine salts or complexing with cyclodextrins/solubilizer. Ocular penetration of NSAID demands an acidic ophthalmic solution where cyclodextrin could prevent precipitation of drug and minimize its ocular irritation potential. The incompatibility of NSAID with benzalkonium chloride is avoided by using polysorbate 80, cyclodextrins or tromethamine. Lysine salts and alpha-tocopheryl polyethylene glycol succinate disrupt corneal integrity, and their use requires caution. Thus a nonirritating ophthalmic solution of NSAID could be formulated by dissolving an appropriate water-soluble salt, in the presence of cyclodextrin or tromethamine (if needed) in mildly acidified purified water (if stability permits) with or without benzalkonium chloride and polyvinyl alcohol. Amide prodrugs met with mixed success due to incomplete intraocular hydrolysis. Suspension and ocular inserts appear irritating to the inflamed eye. Oil drop may be a suitable option for insoluble drugs and ointment may be used for sustained effect. Recent studies showed that the use of colloidal nanoparticle formulations and the potent COX 2 inhibitor bromfenac may enhance NSAID efficacy in eye preparations.