A Second Generation Prostanoid Receptor Antagonist Acting at Multiple Receptor Subtypes.

It has previously been reported that a prototypical compound (AGN 211377), which blocks pro-inflammatory prostanoid receptors (DP1, DP2, EP1, EP4, FP, TP) and leaves open IP and EP2 receptors so that their anti-inflammatory properties could be exerted, produced superior inhibitory effects on cytokine release from human macrophages compared to cyclooxygenase (COX) inhibitors. This favorable activity profile translated into animal studies, with AGN 211377 exceeding the level of inhibition afforded by COX inhibition. AGN 211377 was not, however, a practical drug candidate, having poor bioavailability and cost of goods concerns. Compound 1 (designated AGN 225660) represents a second-generation compound with an entirely different "druggable" core structure. Such a dramatic change in chemical scaffold created uncertainty with respect to matching the effects of AGN 211377. AGN 225660 inhibited RANTES, IL-8, and MCP-1 secretion by at least 50%, from TNFα activated human macrophages. Although AGN 225660 reduced TNFα-evoked MCP-1 release from human monocyte-derived macrophages, it increased LPS-induced MCP-1 secretion (up to 2-fold) from human monocyte-derived dendritic cells. However, AGN 225660 inhibited the release of IL12p 70 and IL-23 from human monocyte-derived dendritic cells stimulated by LPS by more than 70%. This effect of AGN 225660 was reproduced in part by the prototype compound AGN 211377 and a combination of selective DP1, EP1, EP4, FP, and TP antagonists. These findings suggest important effects on T cell skewing and disease modification by this class of therapeutic agents. AGN 225660 exhibited good ocular bioavailability and was active in reducing ocular inflammation associated with phacoemulsification surgery, LPS, and arachidonic acid induced uveitis.

Alternative Drug Delivery for Patients Undergoing Cataract Surgery as Demonstrated in a Canine Model.

PURPOSE: (1) To determine ketorolac concentrations in selected ocular tissues following the intracameral administration of phenylephrine and ketorolac injection 1%/0.3% (OMIDRIA®) delivered in irrigation solution during lens replacement surgery in beagle dogs. (2) To compare the ketorolac initial dose and resultant concentrations from the above study to those achieved in aqueous and vitreous by topical administration in patients undergoing cataract surgery or vitrectomy, respectively. METHODS: Lens replacement surgery with phacoemulsification was performed in 20 female beagle dogs. A fixed combination of phenylephrine and ketorolac injection 1%/0.3% was diluted 125-fold into the balanced salt solution and delivered intracamerally during the phacoemulsification procedure. Ketorolac concentration was determined by liquid chromatography/mass spectrometry. RESULTS: Concentrations of ketorolac when administered by the intracameral route in the dosing solution in dogs were found to be considerably higher in both aqueous and vitreous compared to what is achieved with topical dosing in patients. CONCLUSIONS: Adequate therapeutic concentrations of ketorolac in aqueous and vitreous humor were achieved even at 10 h postdose. Critical concentrations in the aqueous that envelopes the iris/ciliary body, which are sites of prostaglandin E2 synthesis, and the vitreous are not achieved by topical dosing in clinical studies after the surgery, but are by direct intracameral dosing as determined in this study. Based on these studies and clinical data, phenylephrine and ketorolac injection 1%/0.3% delivered during surgery as an irrigation solution may preclude the need for topically administered pre- and postoperative NSAIDs.

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%.

A randomized comparison of to-aqueous penetration of ketorolac 0.45%, bromfenac 0.09% and nepafenac 0.1% in cataract patients undergoing phacoemulsification.

OBJECTIVE: To compare the peak to-aqueous penetration of three nonsteroidal anti-inflammatory drugs: ketorolac tromethamine 0.45%, bromfenac 0.09%, nepafenac 0.1%, and amfenac (the active metabolite of nepafenac) in patients undergoing phacoemulsification. METHODS: A single center, double-masked study randomized 122 patients to receive one of three treatment arms. On-label dosing of ketorolac (BID), bromfenac (BID), and nepafenac (TID) was instructed for 1 day prior to surgery. Patients were instructed to instill one drop the morning of surgery. The patients received four additional doses 1 hour prior to phacoemulsification. After completion of the paracentesis site with a superblade, aqueous humor (0.15 cc) was collected through the peripheral clear cornea with a 30-gauge needle attached to a TB syringe. Following collection, aqueous samples were stored at -40°C prior to analysis. Drug concentrations were analyzed by liquid chromatography tandem mass spectrometry using positive turbo-ion spray ionization and multiple reaction monitoring mode for quantification. An independent sample Student's t-test was used to detect between-group differences. RESULTS: The peak aqueous concentration of ketorolac 0.45% was 10 times the concentration of bromfenac 0.09%, and five times the concentration of and 54% greater than the metabolically inactive nepafenac 0.1%. The mean peak aqueous concentration of ketorolac 0.45% was 688.87 ± 749.6 ng/ml. Bromfenac achieved a mean peak aqueous concentration of 67.64 ± 62.4 ng/ml. The mean peak aqueous concentrations of nepafenac and amfenac were 447.10 ± 225.7 ng/ml and 140.37 ± 56.6 ng/ml, respectively. The peak concentration of ketorolac was statistically significantly greater than bromfenac (P ≤ 0.0005), nepafenac (P ≤ 0.05), and amfenac (P ≤ 0.005). A limitation of this study is that aqueous samples were collected just prior to surgery and not during the postoperative period due to ethical considerations. CONCLUSIONS: Ketorolac 0.45% achieved significantly greater aqueous concentrations when compared to bromfenac 0.09% and the active metabolite of nepafenac 0.1% (amfenac) in patients undergoing phacoemulsification.

Ocular penetration and anti-inflammatory activity of ketorolac 0.45% and bromfenac 0.09% against lipopolysaccharide-induced inflammation.

PURPOSE: Anti-inflammatory activity of topical nonsteroidal anti-inflammatory drugs is mediated by suppression of cyclooxygenase (COX) isoenzymes. This study compared ocular penetration and inflammation suppression of topical ketorolac 0.45% and bromfenac 0.09% ophthalmic solutions in a rabbit model. METHODS: At hour 0, 36 rabbits received ketorolac 0.45%, bromfenac 0.09%, or an artificial tear 3 times once every 20 min. Half of the rabbits in each group then received intravenous injections of lipopolysaccharide (LPS) and fluorescein isothiocyanate (FITC)-dextran at hour 1, and the other half at hour 10. Aqueous and iris-ciliary body (ICB) samples were collected in the former group at hour 2 (peak) and in the latter group at hour 11 (trough) An additional group of 6 animals received only FITC-dextran, and samples were collected 1 h later. Peak and trough nonsteroidal anti-inflammatory drug concentrations were compared with previously determined half-maximal inhibitory concentrations (IC(50)) for COX isoenzymes. RESULTS: Peak and trough aqueous and ICB concentrations of ketorolac were at least 7-fold or greater than those of bromfenac. At peak levels, both ketorolac 0.45% and bromfenac 0.09% significantly inhibited LPS-induced aqueous prostaglandin E(2) and FITC-dextran elevation (P < 0.01). At trough, both study drugs significantly inhibited LPS-induced aqueous prostaglandin E(2) elevation (P < 0.05), but only ketorolac 0.45% significantly reduced LPS-induced aqueous FITC-dextran elevation (P < 0.01). Aqueous and ICB ketorolac concentrations exceeded its IC(50) for COX-1 and COX-2 at peak and trough. Aqueous and ICB bromfenac levels exceeded its IC(50) for COX-2 at peak and trough, but not for COX-1 at trough aqueous levels and peak and trough ICB levels. CONCLUSIONS: Both ketorolac 0.45% and bromfenac 0.09% effectively suppressed inflammation at peak. At trough, only ketorolac 0.45% effectively suppressed inflammation as measured by FITC-dextran leakage. The difference in inflammation suppression may be due to differences in tissue concentrations and/or greater COX-1 suppression by ketorolac 0.45%.

Vitreous nonsteroidal antiinflammatory drug concentrations and prostaglandin E2 levels in vitrectomy patients treated with ketorolac 0.4%, bromfenac 0.09%, and nepafenac 0.1%.

PURPOSE: To assess vitreous concentrations of nonsteroidal antiinflammatory drugs (NSAIDs) and prostaglandin E(2) in patients treated with NSAIDs before vitrectomy. METHODS: This was an investigator-masked, randomized, multicenter study. Patients received ketorolac 0.4% 4 times a day, bromfenac 0.09% 2 times a day, nepafenac 0.1% 3 times a day, or no NSAID for 3 days before surgery. Nonsteroidal antiinflammatory drugs and prostaglandin E(2) levels were determined in vitreous samples collected at the beginning of surgery. RESULTS: Thirty-one patients were included in the analyses. The mean (SD) vitreous concentrations were as follows: ketorolac 2.8 (3.2) ng/mL, bromfenac 0.96 (0.31) ng/mL, nepafenac 1.1 (0.6) ng/mL, and amfenac 2.0 (0.8) ng/mL aligned with the initial concentrations of the topical NSAIDs. Mean (SD) vitreous prostaglandin E(2) levels of the control patients and those treated with ketorolac 0.4%, bromfenac 0.09%, or nepafenac 0.1% were 270.6 (91.7) pg/mL, 189.6 (50.2) pg/mL, 247.2 (38.3) pg/mL, and 267.7 (99.7) pg/mL, respectively. Patients treated with ketorolac 0.4% had significantly lower prostaglandin E(2) levels than those treated with no NSAID (P = 0.047) or nepafenac 0.1% (P = 0.028). CONCLUSION: All three NSAIDs penetrated into the vitreous cavity. Topical therapy with ketorolac may lower preoperative vitreous prostaglandin E(2) levels, which may have a clinical impact on the management of prostaglandin-mediated diseases, including cystoid macular edema.

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.

Comparison of ketorolac 0.4% and bromfenac 0.09% at trough dosing: aqueous drug absorption and prostaglandin E2 levels.

PURPOSE: To compare aqueous drug concentrations and prostaglandin E(2) (PGE(2)) levels in patients treated with ketorolac 0.4% and bromfenac 0.09% at trough dosing. SETTING: Private practice, Wilkes-Barre, Pennsylvania, USA. METHODS: This single-center randomized investigator-masked clinical study comprised 56 patients having cataract surgery. Patients received 1 drop of ketorolac 0.4% or bromfenac 0.09% 6 hours and 12 hours preoperatively consistent with on-label dosing schedules. Aqueous humor was collected at the start of surgery and analyzed for concentrations of ketorolac and bromfenac using a reverse-phase high-performance liquid chromatography-mass spectroscopy system and for PGE(2) levels by competitive enzyme immunoassay. RESULTS: The mean aqueous PGE(2) level was 204.2 pg/mL +/- 95.5 (SD) in patients treated with ketorolac 0.4% and 263.7 +/- 90.0 pg/mL in patients treated with bromfenac 0.09%, (P = .020). The mean aqueous concentration of ketorolac and bromfenac at trough dosing was 130.5 +/- 37.8 ng/mL and 6.2 +/- 3.1 ng/mL, respectively (P = .004). CONCLUSIONS: Higher aqueous levels and greater PGE(2) inhibition were observed in cataract surgery patients treated with ketorolac 0.4% than in patients treated with bromfenac 0.09% at trough dosing. These findings suggest that ketorolac 0.4% administered 4 times a day may provide better control of prostaglandin-mediated inflammation than bromfenac 0.09% administered twice a day.

Prostaglandin E2 inhibition and aqueous concentration of ketorolac 0.4% (acular LS) and nepafenac 0.1% (nevanac) in patients undergoing phacoemulsification.

PURPOSE: To determine the prostaglandin E(2) (PGE(2)) levels and aqueous concentrations achieved with ketorolac 0.4% (Acular LS; Allergan, Inc, Irvine, California, USA) and nepafenac 0.1% (Nevanac; Alcon Laboratories, Inc, Fort Worth, Texas, USA). DESIGN: Single-center, randomized, double-masked study. METHODS: One hundred and thirty-two patients received ketorolac or nepafenac four times daily for two days before cataract extraction. Aqueous samples obtained at surgery were analyzed for PGE(2) levels (competitive enzyme immunoassay) and drug concentrations. RESULTS: More ketorolac eyes than nepafenac eyes had PGE(2) levels less than the level of detection (<100 pg/ml; 26/42 [61.9%] and 7/40 [17.5%], respectively; P < .001). Mean PGE(2) levels in ketorolac eyes were lower than that in nepafenac eyes (159.5 +/- 114.66 pg/ml and 322 +/- 197.8 pg/ml, respectively; P < .001). The mean aqueous level was 1079.1 +/- 881.5 ng/ml with ketorolac and 353.4 +/- 126.0 ng/ml with amfenac. The nepafenac eyes exhibited 588.4 +/- 394.6 ng/ml of the inactive nepafenac molecule (P < .001 vs ketorolac). CONCLUSIONS: Ketorolac 0.4% inhibited PGE(2) and penetrated into aqueous significantly more than nepafenac 0.1%.

Comparison of cyclooxygenase inhibitory activity and ocular anti-inflammatory effects of ketorolac tromethamine and bromfenac sodium.

OBJECTIVE: To compare the cyclooxygenase (COX) activity and anti-inflammatory effects of the nonsteroidal anti-inflammatory drugs (NSAIDs) ketorolac tromethamine (ketorolac) and bromfenac sodium (bromfenac). METHODS: Cyclooxygenase activity and selectivity was determined in vitro by measuring prostaglandin E(2) (PGE(2)) production following incubation of varying concentrations of NSAID with human recombinant COX-1 or COX-2 and arachidonic acid. Anti-inflammatory effects were evaluated in a rabbit model in which an ocular inflammatory response was induced by intravenous injection of 10 microg/kg lipopolysaccharide (LPS). In study animals, one eye was treated with 50 microL (+/-) ketorolac 0.4% (Acular LS) or bromfenac 0.09% (Xibrom) and the other eye with 50 microL buffered saline. In control animals, both eyes were treated with vehicle. All animals were treated twice: 2 hours and 1 hour before LPS. MAIN OUTCOME MEASURES: PGE(2) production in vitro, measured by enzyme immunoassay; fluorescein isothiocyanate (FITC)-dextran leakage into the anterior chamber, measured by fluorophotometry; aqueous PGE(2) levels in vivo, measured by ELISA immunoassay. RESULTS: Ketorolac was six times more active against COX-1 (IC(50) = 0.02 microM) than COX-2 (IC(50) = 0.12 microM) while bromfenac was approximately 32 times more active against COX-2 (IC(50) = 0.0066 microM) than COX-1 (IC(50) = 0.210 microM). In the animal model, both drugs resulted in nearly complete inhibition of FITC-dextran leakage and PGE(2) production in the anterior chamber of treated eyes. There was also a 79% inhibition (p < 0.001) of FITC-dextran leakage in the contralateral eyes of bromfenac-treated rabbits, and a 22.5% inhibition (not statistically significant) in the contralateral eyes of ketorolac-treated rabbits. CONCLUSIONS: Ketorolac is relatively COX-1 selective while bromfenac is potently selective for COX-2 over COX-1. In the animal model, both ketorolac 0.4% and bromfenac 0.09% demonstrated maximal anti-inflammatory activity in treated eyes. Only bromfenac 0.09% had a significant effect on the contralateral eye, suggesting possible systemic absorption of this drug.

Comparison of ketorolac tromethamine, diclofenac sodium, and loteprednol etabonate in an animal model of ocular inflammation.

PURPOSE: The aim of this study was to compare the anti-inflammatory activities of ketorolac tromethamine 0.4% and 0.1%; diclofenac sodium 0.1%; and loteprednol etabonate 0.5% suspension in an animal model of ocular inflammation. METHODS: An ocular inflammatory response was induced in New Zealand White rabbits by the intravenous (i.v.) administration of 10 microg/kg lipopolysaccharide (LPS). In study animals, 1 eye was treated topically with 50 microL of study medication (n = 8 animals per drug) and the other eye was treated topically with a 50-microL vehicle (buffered saline). In control animals (n = 8), both eyes were treated with vehicle. All animals were treated twice: 2 h and 1 h before LPS challenge. The breakdown of the blood-aqueous barrier in the anterior chamber was measured by fluorophotometry (FITC-dextran 30 mg/kg, i.v. given immediately after LPS challenge). Aqueous prostaglandin E(2) (PGE(2)) levels were measured using an enzyme-linked immunosorbent assay (ELISA) immunoassay. RESULTS: Ketorolac 0.4% resulted in a nearly complete inhibition of endotoxin-induced increases in FITC-dextran and PGE(2) synthesis (P < 0.001 vs. vehicle). Diclofenac 0.1% had much less of an effect on these parameters (P < 0.01 vs. ketorolac 0.4%). Loteprednol 0.5% was no more effective than vehicle at inhibiting increases in FITC-dextran. CONCLUSIONS: Ketorolac has greater anti-inflammatory effects than diclofenac and loteprednol.

Efficacy of low concentrations of ketorolac tromethamine in animal models of ocular inflammation.

PURPOSE: To determine if topical ophthalmic application of ketorolac tromethamine concentrations below 0.5% can block the biochemical and physiological processes associated with chemically induced ocular inflammation in rabbits. METHODS: Ocular inflammation was induced in rabbits by intravenous (i.v.) injection of endotoxin (2.5 microg/kg) isolated from Salmonella typhimurium, or by a topical application of arachidonic acid (1.0%). The effect of ketorolac (at concentrations ranging from 0.001%-0.5%) on ocular inflammation was determined by measuring changes in the blood-aqueous barrier, using fluorophotometry (dextran-isothiocyanate-fluorescein; FITC-dextran 2%) and by measuring changes in aqueous humor protein concentrations. Changes in aqueous humor prostaglandin E(2) (PGE(2)) concentrations were also measured. RESULTS: Ketorolac 0.01%-0.5% produced substantial decreases in endotoxin-induced fluorescein leakage into the aqueous humor. The decrease produced by ketorolac 0.1% was comparable to that produced by ketorolac 0.5%. Ketorolac 0.1%-0.5% produced substantial decreases in endotoxin-induced increases in prostaglandin concentrations in the aqueous humor, and in arachidonic acid-induced protein leakage into the aqueous humor. CONCLUSIONS: Topical application of ketorolac concentrations as low as 0.01%-0.1% significantly reduce chemically induced ocular inflammation in rabbits.

EP3, but not EP2, FP, or TP prostanoid-receptor stimulation may reduce intraocular pressure.

Stimulation of DP, but not TP or FP, prostanoid receptors has previously been shown to reduce intraocular pressure (IOP) in rabbits. However the role of EP receptors (EP1, EP2, and EP3 subtypes) has not been studied extensively. Sulprostone, RS-61565, and RS-20216 have been studied for effects on rabbit IOP, and their prostanoid-receptor profiles characterized. The data suggest that the EP3, but not EP2, FP, or TP activity of these agonists correlated with the intraocular hypotensive effects. Moreover, RS-20216 lowered IOP at a dose of 5 micrograms for up to 12 hr after administration. In contrast to PGE1 and PGE2, which elicited both hyper- and hypotensive responses, sulprostone, RS-61565, and RS-20216 elicited only a hypotensive responses with no signs of ocular irritation. Thus stimulation of the EP3 receptor results in a lowering of IOP in rabbits. Compounds specific for this receptor subtype may act as novel therapeutic agents for the treatment of glaucoma.

Reversible dementia with idiopathic hypereosinophilic syndrome.

A 66-year-old woman with hypereosinophilic syndrome became rapidly demented. Evaluation revealed CSF eosinophilia, background slowing on EEG, and periventricular MRI abnormalities. Following steroid therapy, there was rapid resolution of the dementia and normalization of CSF and EEG. These findings support the concept of a direct neurotoxic effect on the human CNS produced either by eosinophils or possibly by eosinophil-derived neurotoxins.