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Eye (London, England) Feb 2021To evaluate the effect of brimonidine tartrate 0.15% ophthalmic solution on pupil size under scotopic condition and upper eyelid position.
BACKGROUND
To evaluate the effect of brimonidine tartrate 0.15% ophthalmic solution on pupil size under scotopic condition and upper eyelid position.
METHODS
This study comprised 72 eyes of 36 healthy subjects. A single drop of brimonidine tartrate 0.15% ophthalmic solution was instilled in the right eye and artificial tear was instilled in the left eye. Pupil size was measured using an infra-red pupillometer under scotopic condition before and at 30 min, 2, 4, 6, 8 and 10 h after instillation. Measurement of margin reflex distance 1 (MRD1) was performed using a millimetre ruler before and after at 10 min after instillation.
RESULTS
The mean age of the subjects was 32.19 ± 11.43 years (range 10-52 years), 17 were female and 19 were male. Before brimonidine instillation, the mean pupil size was 6.09 ± 1.03 mm in the brimonidine eyes and 6.06 ± 1.04 mm in the control eyes. There was a significant decrease in mean pupil size at 30 min (4.45 ± 1.04), 2 h (4.49 ± 1.06), 4 h (4.59 ± 1.06), 6 h (4.89 ± 1.06) and 8 h (5.38 ± 1.02) after instillation compared to before in brimonidine eyes (p < 0.001 for all). There was a significant miosis continued for at least 6 h (5.95 ± 1.03) in control eyes (p < 0.001). There was no significant change in MRD1, before and after instillation both in brimonidine and control eyes.
CONCLUSIONS
Brimonidine tartrate 0.15% had a significant miosis under scotopic condition for at least 8 h after instillation and had a significant miosis on the untreated eye for at least 6 h.
Topics: Adolescent; Adult; Brimonidine Tartrate; Child; Eyelids; Female; Humans; Male; Middle Aged; Ophthalmic Solutions; Pupil; Quinoxalines; Young Adult
PubMed: 32518394
DOI: 10.1038/s41433-020-1007-9 -
Frontiers in Medicine 2023To investigate the differences between 0.2 and 0.15% brimonidine tartrate eye drops for anti-mydriatic effects and the optical quality under different light conditions.
AIMS
To investigate the differences between 0.2 and 0.15% brimonidine tartrate eye drops for anti-mydriatic effects and the optical quality under different light conditions.
METHODS
This prospective study involved 80 consecutive high myopia patients undergoing implantation of a V4c ICL. The patients were randomly instilled with brimonidine 0.2 and 0.15% 2 weeks postoperatively. Visual quality, pupil center, pupil size, and refraction under different light conditions were measured before and 0.5 h after brimonidine administration. A symptom questionnaire was also evaluated.
RESULTS
There was no statistical difference in the static and dynamic pupil diameters and velocity after LS between the two groups ( > 0.05). The 0.2% group had significant changes in pupil center before and after treatment, while there was no obvious movement of the 0.15% group under all illumination condition ( > 0.05). The OSI after treatment of the 0.15% group was lower than that of 0.2% group ( = 0.012). The PVA9% and PVA100% of the 0.15% group was higher than that of 0.2% group in the dark ( = 0.009, = 0.012). The HOA RMS of the 0.15% group was lower than that of 0.2% group ( = 0.016). The QIRC score in the 0.15% group was significantly higher than that in the 0.2% group ( = 0.043).
CONCLUSION
0.15 and 0.2% brimonidine tartrate eye drops had similar anti-mydriatic ability, while 0.15% group had better visual quality than 0.2% concentration, and hardly introduced pupil shift. 0.15% brimonidine tartrate eye drops may be more suitable for patients with nocturnal glare symptoms in the early postoperative period after ICL implantation.
PubMed: 37256086
DOI: 10.3389/fmed.2023.1160414 -
American Journal of Ophthalmology Apr 2023To confirm the superiority of the intraocular pressure (IOP)-lowering effect of the ripasudil-brimonidine fixed-dose combination (RBFC, K-232) to ripasudil 0.4% or...
PURPOSE
To confirm the superiority of the intraocular pressure (IOP)-lowering effect of the ripasudil-brimonidine fixed-dose combination (RBFC, K-232) to ripasudil 0.4% or brimonidine 0.1% ophthalmic solution.
DESIGN
Two prospective multicenter, randomized, double- or single-masked, active-controlled, phase 3 trials.
METHODS
Patients with primary open-angle glaucoma or ocular hypertension whose IOP level was ≥18 mm Hg during treatment with ripasudil or brimonidine alone were randomized to 2 groups (RBFC and ripasudil) in a 1:1 ratio in the ripasudil-controlled trial and to 3 groups (RBFC, brimonidine, and ripasudil-brimonidine combination) in a 2:2:1 ratio in the brimonidine-controlled trial. The allocated study drugs were instilled twice daily for 8 weeks. The primary efficacy endpoint was the change in IOP 2 hours after instillation (11 AM) from the baseline to weeks 4, 6, and 8.
RESULTS
There were 206 patients randomized in the ripasudil-controlled trial. Changes in IOP were -2.6 and -1.2 mm Hg in the RBFC and ripasudil groups, respectively, with a difference of -1.4 mm Hg (95% CI = -1.8 to -1.0 mm Hg; P < .001). There were 282 randomized patients in the brimonidine-controlled trial. Changes in IOP were -3.4 and -1.5 mm Hg in the RBFC and brimonidine groups, respectively, with a difference of -1.8 mm Hg (95% CI = -2.3 to -1.4 mm Hg; P < .001). The most frequent adverse event was conjunctival hyperemia.
CONCLUSIONS
The IOP-lowering effect of RBFC was superior to that of ripasudil or brimonidine.
Topics: Humans; Brimonidine Tartrate; Glaucoma, Open-Angle; Prospective Studies; Antihypertensive Agents; Quinoxalines; Treatment Outcome; Randomized Controlled Trials as Topic; Ocular Hypertension; Intraocular Pressure; Double-Blind Method
PubMed: 36410471
DOI: 10.1016/j.ajo.2022.11.017 -
BMC Anesthesiology Dec 2021To determine the hypnotic and analgesic effects of brimonidine, and evaluate its efficacy and safety for general anesthesia. Potentiation of pentobarbital sleeping time...
BACKGROUND
To determine the hypnotic and analgesic effects of brimonidine, and evaluate its efficacy and safety for general anesthesia. Potentiation of pentobarbital sleeping time following brimonidine administration was observed in mice, as was the analgesic activity of brimonidine.
METHODS
The median effective dose (ED) and lethal dose (LD) of intraperitoneally injected brimonidine were determined in hypnotized mice. In addition, the LD of intravenously injected brimonidine, and ED of intravenously, intramuscularly, and intrarectally injected brimonidine in hypnotized rabbits were determined. Finally, the synergistic anesthetic effect of brimonidine and chloral hydrate was evaluated in rabbits.
RESULTS
Intraperitoneal injection of 10 mg/kg brimonidine enhanced the hypnotic effect of a threshold dose of pentobarbital. Intraperitoneally injected brimonidine produced dose-related analgesic effects in mice. The ED of intraperitoneally administered brimonidine in hypnotized mice was 75.7 mg/kg and the LD was 379 mg/kg. ED values of intravenous, intramuscular, and intrarectal brimonidine for hypnosis in rabbits were 5.2 mg/kg, 8.8 mg/kg, and 8.7 mg/kg, respectively; the LD of intravenous brimonidine was 146 mg/kg. Combined intravenous administration of 0.6 mg/kg brimonidine and 0.03 g/kg chloral hydrate had a synergistic anesthetic effect.
CONCLUSIONS
Brimonidine elicited hypnotic and analgesic effects after systemic administration and exhibited safety. Moreover, brimonidine enhanced the effects of other types of narcotics when combined.
Topics: Adrenergic alpha-2 Receptor Agonists; Anesthesia, General; Animals; Brimonidine Tartrate; Dose-Response Relationship, Drug; Mice; Rabbits
PubMed: 34861822
DOI: 10.1186/s12871-021-01516-1 -
International Journal of Ophthalmology 2020To evaluate the mechanism of which brimonidine tartrate 0.15% causes clinical hypersensitivity.
AIM
To evaluate the mechanism of which brimonidine tartrate 0.15% causes clinical hypersensitivity.
METHODS
A prospective case-control study comparing 8 glaucoma patients with clinical hypersensitivity to brimonidine to a control group consisting 13 healthy volunteers. Blood samples were stimulated with brimonidine 0.15%, timolol 0.5% or brimonidine tartrate/timolol maleate 0.2%/0.5%. Premixed antibodies (CD63/FITC and aIgE/PE) were added for direct staining and whole-blood samples were lysed, fixed and analyzed by a flow cytometer. The basophil population was defined by high IgE cell expression. Degranulation was identified by the expression of the activation molecule CD63.
RESULTS
Basophil activation was not significant when comparing percent of activated basophils of patients and healthy controls after exposure to brimonidine (2.58%, 2.45%, respectively, =0.72). There was a significant suppression of basophil activation when a combination of brimonidine-timolol (0.87%) was compared to timolol (2.27%; =0.012) and to brimonidine alone (2.58%; =0.017).
CONCLUSION
The results of our study do not support the hypothesis that brimonidine induces an immediate allergic reaction. Basophil activation was suppressed by the presence of β-blockers in patients hypersensitive to brimonidine and in healthy individuals. This finding indicates that timolol suppress brimonidine drug reaction by a different mechanism.
PubMed: 32309191
DOI: 10.18240/ijo.2020.03.21 -
PloS One 2022To evaluate the concentrations of brimonidine and timolol in the vitreous and aqueous humors after instillation of a 0.1% brimonidine tartrate and 0.5% timolol... (Clinical Trial)
Clinical Trial
Brimonidine and timolol concentrations in the human vitreous and aqueous humors after topical instillation of a 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution: An interventional study.
PURPOSE
To evaluate the concentrations of brimonidine and timolol in the vitreous and aqueous humors after instillation of a 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution.
METHODS
This single-arm open-label interventional study included patients with macular holes or idiopathic epiretinal membranes who were scheduled for vitrectomy. Written informed consent was obtained from all participants. A 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution was administered topically twice daily for 1 week preoperatively. The vitreous and aqueous humors were sampled before vitrectomy, and brimonidine and timolol concentrations were quantified using liquid chromatography-tandem spectrometry. This study was registered with the Japan Registry of Clinical Trials (jRCT, ID jRCTs051200008; date of access and registration: April 28, 2020). The study protocol was approved by the University of Fukui Certified Review Board (CRB) and complied with the tenets of the Declaration of Helsinki.
RESULTS
Eight eyes of eight patients (7 phakic eyes and 1 pseudophakic eye) were included in this study. The mean brimonidine concentrations in the vitreous and aqueous humors were 5.04 ± 4.08 nM and 324 ± 172 nM, respectively. Five of the eight patients had brimonidine concentrations >2 nM in the vitreous humor, which is necessary to activate α2 receptors. The mean timolol concentrations in the vitreous and aqueous humors were 65.6 ± 56.0 nM and 3,160 ± 1,570 nM, respectively. Brimonidine concentrations showed significant positive correlations with timolol concentrations in the vitreous humor (P < 0.0001, R2 = 0.97) and aqueous humor (P < 0.0001, R2 = 0.96).
CONCLUSIONS
The majority of patients who received a 0.1% brimonidine tartrate and 0.5% timolol topical fixed-combination ophthalmic solution showed a brimonidine concentration >2 nM in the vitreous humor. Brimonidine and timolol may be distributed in the ocular tissues through an identical pathway after topical instillation.
Topics: Humans; Aqueous Humor; Brimonidine Tartrate; Ophthalmic Solutions; Timolol; Vitreous Body
PubMed: 36454807
DOI: 10.1371/journal.pone.0277313 -
Photochemistry and Photobiology Nov 2022We investigated whether topical brimonidine delayed or enhanced the development of squamous cell carcinoma (SCC) when ultraviolet radiation (UVR) was applied to a...
We investigated whether topical brimonidine delayed or enhanced the development of squamous cell carcinoma (SCC) when ultraviolet radiation (UVR) was applied to a well-established murine model. Hairless female mice (n = 125) were randomized into five groups and treated as follows: 1% brimonidine cream before UVR (Group 1), 0.33% brimonidine gel before UVR (Group 2), 1% brimonidine cream after UVR (Group 3), UVR only (control; Group 4) and 1% brimonidine cream only (control; Group 5). For each animal, the first four tumors were recorded and followed until three tumors reached 4 mm or one tumor reached 12 mm in diameter. All animal experiments continued for up to 365 days or until death. Application of 1% brimonidine cream before UVR delayed tumor development relative to control mice treated with UVR alone (P = 0.000006). However, when 0.33% brimonidine gel was applied before UVR (P = 0.313) or 1% brimonidine cream was applied after UVR (P = 0.252), there was no significant delay in tumor development relative to control mice treated with UVR alone. The development of the second and third tumors followed a similar pattern. Topical 1% brimonidine cream applied before UVR exposure delayed SCC development in hairless mice. In contrast, when brimonidine was applied after UVR there was no significant delay in tumor development. These results suggest that the 1% brimonidine cream probably absorbed the UVR, and therefore, a delay in tumor formation was only seen when brimonidine was applied before irradiation. However, there can be multiple reasons for this delay in photocarcinogenesis.
Topics: Female; Mice; Animals; Mice, Hairless; Ultraviolet Rays; Brimonidine Tartrate; Skin Neoplasms; Carcinoma, Squamous Cell; Neoplasms, Radiation-Induced
PubMed: 35338500
DOI: 10.1111/php.13622 -
Ophthalmology and Therapy Mar 2020This study was aimed to compare ocular tissue distribution and systemic exposure of brimonidine and timolol after single topical administration to rabbits of...
INTRODUCTION
This study was aimed to compare ocular tissue distribution and systemic exposure of brimonidine and timolol after single topical administration to rabbits of fixed-combination ophthalmic solution of 0.1% brimonidine tartrate and 0.5% timolol and single drugs (0.1% brimonidine tartrate ophthalmic solution or 0.5% timolol ophthalmic solution) or concomitant administration of single drugs.
METHODS
Rabbits were treated with a single topical administration of each ophthalmic solution or concomitant administration of single drugs. For concomitant administration, 0.1% brimonidine tartrate was administered after 0.5% timolol instillation successively within 10 s (without interval) or with 5-min intervals. Brimonidine and timolol concentrations in the aqueous humor, retina/choroid, vitreous body, and plasma were determined with liquid chromatography-tandem mass spectrometry.
RESULTS
The area under the curve values of both drugs in the aqueous humor after fixed-combination administration were comparable to those after concomitant administration. The value of brimonidine was comparable to that after 0.1% brimonidine tartrate administration, whereas the value of timolol was 1.6-fold higher than that after 0.5% timolol administration. The plasma area under the curve value of brimonidine did not differ between fixed-combination and single-drug administrations, but that of timolol was higher after fixed-combination administration than after single-drug administration. Similar concentration-time curves of brimonidine were observed in the posterior ocular tissues in all groups. For concomitant administration, both drug concentrations in the aqueous humor without an administration interval were lower than those with 5-min intervals.
CONCLUSION
There was no difference in the effect of formulation compositions on ocular and systemic pharmacokinetics among the ophthalmic solutions, but brimonidine may alter the ocular and systemic absorption of timolol, which is possibly due to its pharmacologic action. We demonstrated the importance of an administration interval in the concomitant administration of these drugs. This concern could be avoided by using a fixed combination of brimonidine and timolol.
PubMed: 31953739
DOI: 10.1007/s40123-020-00229-x -
Advances in Therapy Aug 2023Multidrug regimens for glaucoma treatment often result in adherence issues due to inconvenience; these issues may be improved with fixed-dose combination drugs. The... (Randomized Controlled Trial)
Randomized Controlled Trial
INTRODUCTION
Multidrug regimens for glaucoma treatment often result in adherence issues due to inconvenience; these issues may be improved with fixed-dose combination drugs. The ophthalmic solution of ripasudil-brimonidine fixed-dose combination (RBFC; K-232) is the first treatment combining a Rho kinase inhibitor and an α-adrenoceptor agonist, and has demonstrated ability to lower intraocular pressure (IOP) and have various effects on conjunctival hyperemia and corneal endothelial cell morphology. This study evaluates the pharmacologic effects of RBFC treatment versus its separate components-ripasudil or brimonidine.
METHODS
This single-center, prospective, randomized, open-label, blinded endpoint study with 3 × 3 crossover design randomly assigned healthy adult men to three groups (1:1:1) to undergo consecutive 8-day administration phases (with drug-free intervals of at least 5 days). Subjects received twice-daily instillation of RBFC → ripasudil → brimonidine (group A), ripasudil → brimonidine → RBFC (group B), or brimonidine → RBFC → ripasudil (group C). Endpoints included change in IOP, severity of conjunctival hyperemia, corneal endothelial cell morphology, pupil diameter, and pharmacokinetics.
RESULTS
Eighteen subjects were assigned in total (six to each group). RBFC significantly reduced IOP from baseline at 1 h post-instillation on days 1 and 8 (12.7 vs. 9.1 and 9.0 mmHg, respectively; both P < 0.001), and provided significantly greater IOP reductions than ripasudil or brimonidine at several time points. The most common adverse drug reaction with all three treatments was mild conjunctival hyperemia, which transiently increased in severity with RBFC or ripasudil, peaking at 15 min post-instillation. In post hoc analyses, conjunctival hyperemia scores were lower with RBFC than with ripasudil at several time points. Transient morphologic changes in corneal endothelial cells occurred for up to several hours with RBFC or ripasudil, but not with brimonidine. Pupil diameter did not change with RBFC.
CONCLUSION
RBFC significantly reduced IOP compared with each agent alone. A combination of each agent's pharmacologic profile was observed in that of RBFC.
TRIAL REGISTRATION
Japan Registry of Clinical Trials; Registration No. jRCT2080225220.
Topics: Male; Adult; Humans; Brimonidine Tartrate; Glaucoma, Open-Angle; Ocular Hypertension; Prospective Studies; Hyperemia; Endothelial Cells; Intraocular Pressure; Ophthalmic Solutions; Antihypertensive Agents; Quinoxalines
PubMed: 37330927
DOI: 10.1007/s12325-023-02534-w -
BMC Ophthalmology Apr 2024Myopia is becoming a huge burden on the world's public health systems. The purpose of this study was to explore the effect of brimonidine in the treatment of...
BACKGROUND
Myopia is becoming a huge burden on the world's public health systems. The purpose of this study was to explore the effect of brimonidine in the treatment of form-deprivation myopia (FDM) and the relationship between intraocular pressure (IOP) and myopia development.
METHODS
Monocular form deprivation myopia (FDM) was induced in three-week-old pigmented male guinea pigs. They were treated with 3 different methods of brimonidine administration (eye drops, and subconjunctival or intravitreal injections). Four different concentrations of brimonidine were tested for each method (2µg/µL, 4µg/µL, 20µg/µL, and 40µg/µL). All treatments continued for a period of 21 days. Tonometry, retinoscopy, and A-scan ultrasonography were used to monitor intraocular pressure, refractive error and axial length (AL), respectively.
RESULTS
Treatment with subconjunctival brimonidine at 40µg/µL, and intravitreal brimonidine at 2µg/µL and 4µg/µL, inhibited the development of FDM. The myopic refraction, excessive axial length, and elevation of IOP were significantly decreased. Brimonidine in eye drops was ineffective.
CONCLUSION
Brimonidine at appropriate doses significantly reduced the development of FD myopia in guinea pigs. The IOP may change with FD myopia.
Topics: Male; Animals; Guinea Pigs; Brimonidine Tartrate; Myopia; Refractive Errors; Refraction, Ocular; Ophthalmic Solutions; Sensory Deprivation; Disease Models, Animal
PubMed: 38605375
DOI: 10.1186/s12886-024-03433-6