Azithromycin Ophthalmic Solution Research Articles

Efficacy and safety of topical azithromycin therapy in patients with blepharitis and meibomian gland dysfunction

PurposeTo assess the effects of 1% azithromycin ophthalmic solution (AZM) in patients with bacterial blepharitis accompanied by meibomian gland dysfunction (MGD).Study designA multicenter, single arm, prospective interventional study.MethodsAZM was administered to the affected eyes twice daily for the first 2 days and once daily for the subsequent 12 days. Lid margin hyperaemia/redness, collarette at the root of the eyelashes, conjunctival hyperaemia, foreign body sensation, and epiphora were assessed on Days 1, 14, and 28. The Dry Eye-related Quality of Life Score (DEQS) and objectives related to MGD, including lid vascularity, lid margin irregularity, foaming, lid plugging, keratoconjunctival disorders, Marx line, meibum grade, and tear breakup time, were also assessed. Bacterial culture of the conjunctival sac and meibum was performed on Days 1 and 14.ResultsTwenty-four eyes of 24 patients (10 men/14 women, mean age 72.3 ± 13.2) were included. On Days 14 and 28, the total score, lid vascularity, lid plugging, and meibum grade showed significant improvement (p < 0.05). On Day 1, 71 strains were isolated from 22 of the 24 eyes (91.7%). Cutibacterium acnes, Corynebacterium spp., and Staphylococci were detected at high frequencies. The overall disappearance rates of the bacteria in the conjunctival sac and meibum at the end of treatment were 65.7% and 58.3%, respectively. No serious ocular or systemic adverse events were observed.ConclusionFourteen-day treatment with AZM was effective in patients with blepharitis accompanied by MGD, and the efficacy of AZM persisted for a period after the treatment.

Analysis of treatment protocols using azithromycin eye drops for bacterial blepharitis: second report-bacteriological investigation.

To gain new insights into the etiology of blepharitis, we investigated the causative bacteria in patients with blepharitis and the effects of 1% azithromycin ophthalmic solution. A multicenter, prospective observational study. After the subjects were diagnosed as having blepharitis they were administered 1% azithromycin ophthalmic solution for up to 14 days. Bacterial cultures and smear microscopic examinations of the eyelid margin were conducted at the initial visit, after administering eye drops, and 1 month after the end of eye drop administration. The minimum inhibitory concentrations (MICs) of azithromycin were measured. At the initial visit, the bacterial morphology determined by smear microscopic examinations coincided with that of strains isolated by culture taken from 22 of 45 patients. All detected bacteria were gram-positive, and Corynebacterium spp., Cutibacterium acnes, Staphylococcus epidermidis, Streptococcus spp., and Enterococcus faecalis were isolated most commonly. Compared with the initial visit the number of isolated strains per eye decreased significantly at 7 days after the start of eye drop administration and 1 month after the end of eye drop administration. The azithromycin MICs were temporarily increased after the start of eye drops but then decreased. Our study suggests that in blepharitis pathogenicity is characterized by increased strain numbers and amounts of indigenous bacteria. Administering a 1% azithromycin ophthalmic solution suppresses the number of bacterial strains within 1 month after the end of eye drop administration without increasing drug resistance.

Pharmacokinetics of Azithromycin, Levofloxacin, and Ofloxacin in Rabbit Extraocular Tissues After Ophthalmic Administration.

IntroductionAzithromycin demonstrates high tissue distribution and prolonged elimination half-life. In this study, we monitored the pharmacokinetics of a single ophthalmic administration of 1% azithromycin ophthalmic solution containing polycarbophil in the extraocular tissues, including the eyelid, and compared it with that of two commercial ophthalmic products, 1.5% levofloxacin ophthalmic solution and 0.3% ofloxacin ophthalmic ointment.MethodsRabbits were treated with either a single topical administration of 1% azithromycin ophthalmic solution, 1.5% levofloxacin ophthalmic solution, or 0.3% ofloxacin ophthalmic ointment. The eyelid, conjunctiva, and cornea were collected at 0.25, 0.5, 1, 2, 4, 8, and 24 h post-administration. Tissue samples were pretreated for drug concentration measurements by ultra-performance liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were determined by non-compartmental analysis.ResultsAzithromycin was rapidly absorbed, and its levels remained near the observed maximum concentrations for up to 24 h post-administration in all tissue. In contrast, extraocular tissue concentrations of levofloxacin and ofloxacin decreased with time. The maximum concentrations of azithromycin, levofloxacin, and ofloxacin were 35.6, 34.1, and 55.1 µg/g in the eyelid, 44.2, 46.8, and 20.4 µg/g in the conjunctiva, and 79.9, 18.0, and 2.21 µg/g in the cornea, respectively. The values of the area under the curve from 0 to 24 h after administration of azithromycin, levofloxacin, and ofloxacin were 602, 58.5, and 267 µg·h/g in the eyelid, 837, 43.2, and 51.9 µg·h/g in the conjunctiva, and 1250, 26.4, and 5.46 µg h/g in the cornea, respectively.ConclusionThe drug concentrations of azithromycin and levofloxacin were relatively comparable among the extraocular tissues following topical administration of the respective ophthalmic solutions, whereas the concentrations of ofloxacin varied following dosing of its ophthalmic ointment. The slow elimination profile in any extraocular tissue of rabbits was unique to azithromycin, and led to the demonstration of high exposures of azithromycin in all extraocular tissues after ophthalmic administration.FundingThis research and Rapid Service Fees were supported by Senju Pharmaceutical Co., Ltd.

Update and critical appraisal of topical azithromycin ophthalmic 1% (Azasite) solution in the treatment of ocular infection

Azithromycin is an azalide that acts by binding to the 50S ribosomal subunit of susceptible microorganisms and interfering with microbial protein synthesis. Azithromycin is also noted by anti-inflammatory and immunomodulatory activity. AzaSite® (Inspire Pharmaceuticals, Inc, Durham, NC) is azithromycin ophthalmic solution, 1% formulated in polycarbophil (the aqueous mucoadhesive polymer contained in DuraSite®) that delivers high and prolonged azithromycin concentrations in a variety of ocular tissues, including the conjunctiva, cornea and particularly the eyelid. AzaSite was approved by the Food and Drug Administration (FDA) in the US in 2007, for the treatment of bacterial conjunctivitis caused by susceptible isolates. This article aims to evaluate the peer-reviewed published scientific literature and to define well established uses of AzaSite eye drops in the field of ocular infections.

Clinical spectrum in congenital nasal duct obstruction

Azithromycin is an azalide that acts by binding to the 50S ribosomal subunit of susceptible microorganisms and interfering with microbial protein synthesis. Azithromycin is also noted by anti-inflammatory and immunomodulatory activity. AzaSite® (Inspire Pharmaceuticals, Inc, Durham, NC) is azithromycin ophthalmic solution, 1% formulated in polycarbophil (the aqueous mucoadhesive polymer contained in DuraSite®) that delivers high and prolonged azithromycin concentrations in a variety of ocular tissues, including the conjunctiva, cornea and particularly the eyelid. AzaSite was approved by the Food and Drug Administration (FDA) in the US in 2007, for the treatment of bacterial conjunctivitis caused by susceptible isolates. This article aims to evaluate the peer-reviewed published scientific literature and to define well established uses of AzaSite eye drops in the field of ocular infections.

Limited Azithromycin Localization to Rabbit Meibomian Glands Revealed by LC-MS-Based Bioanalysis and DESI Imaging.

Meibomian gland dysfunction (MGD) is the leading cause of dry eye, and although it affects approximately 4% of the population, treatment options remain limited. Topical azithromycin is one of the most promising pharmacological agents because of its multiple mechanisms of action and long sustainability. Azithromycin is frequently used as an off-label medication in the U.S. However, although azithromycin is presumed to act directly on meibomian gland cells, the mechanisms of action that contribute to its clinical efficacy remain unclear because no studies using a pharmacokinetic approach have been performed. Therefore, we aimed to clarify whether topical azithromycin reaches the meibomian glands sufficiently to generate a biological effect. We measured azithromycin concentrations in rabbit meibomian glands collected using a recently developed method. Moreover, we also visualized the azithromycin micro-distribution using desorption electrospray ionization (DESI) imaging. Azithromycin concentration in the meibomian glands reached only 0.8 µg/g tissue following a single application of a 1% azithromycin ophthalmic solution and was 1000-fold lower than the concentration in conjunctival epithelium. Similarly, no signal was observed in the meibomian glands on DESI images. Our results clearly demonstrated that topical azithromycin had limited access to the meibomian glands and was predominantly distributed in ocular surface tissues such as the palpebral conjunctiva and lid margins. These findings provide new insight into the clinical responses to topical azithromycin therapy and will aid in the further development of effective drugs with more suitable pharmacokinetic properties.

Meibomian Gland Dysfunction Model in Hairless Mice Fed a Special Diet With Limited Lipid Content.

A novel meibomian gland dysfunction (MGD) model was developed to facilitate understanding of the pathophysiology of MGD and to evaluate treatment with azithromycin ophthalmic solution (azithromycin). MGD was induced in HR-1 hairless mice by feeding them a special diet with limited lipid content (HR-AD). Male HR-1 hairless mice were fed an HR-AD diet for 16 weeks. Development of MGD was assessed by histopathology at 4-week intervals. The lid margin was observed by slit-lamp examination. After cessation of the HR-AD diet, the mice were fed a normal diet to restore normal eye conditions. Expression of cytokeratin 6 was determined by immunostaining. We evaluated the effects of topically applied azithromycin on the plugged orifice in this model. After mice were fed the HR-AD diet, histopathology analysis showed hyperkeratinization of the ductal epithelium in the meibomian gland. Ductal hyperkeratinization resulted in the loss of acini, followed by atrophy of the gland. Slit-lamp examination revealed a markedly plugged orifice, telangiectasia, and a toothpaste-like meibum compared with that of a normal eyelid. Cessation of feeding with HR-AD ameliorated both the MGD signs and the expression of cytokeratin 6, restoring the tissue to a histologically normal state. Azithromycin treatment significantly decreased the number of plugged orifices and ameliorated atrophy, as revealed by histopathologic analysis. We developed a novel model that mimics human MGD signs in HR-1 hairless mice fed an HR-AD diet. Azithromycin treatment led to therapeutic improvement in this model. This MGD model could be useful for the evaluation of drug candidates for MGD.

On the problem of local antibiotic therapy in children with ocular surface diseases

The efficacy and safety of topical Azithromycin ophthalmic solution 1.5 % has been evaluated in treatment of bacterial conjunctivitis and post-traumatic keratitis in children, and the possibility of its use for prevention of infectious complications after ocular surface trauma. Topical Azithromycin ophthalmic solution 1.5 % was used in 32 children: with bacterial conjunctivitis (21), corneal foreign body (5), traumatic corneal erosion (3), post-traumatic keratitis (3). Topical Azithromycin ophthalmic solution 1.5% was shown to have a significant antibacterial activity and a convenient dosing schedule. No side effects, including eye irritation, have been noted. Conclusion: topical Azithromycin ophthalmic solution 1.5 % could be considered as the medication of choice in treatment of bacterial conjunctivitis and post-traumatic keratitis in children. It also could be used in the complex prevention of infections complications in eye surface traumatic lesions.

Azithromycin 1% ophthalmic solution for treatment of blepharitis

Blepharitis is characterized by chronic inflammation of the lid margins, which may appear as simple hyperemia or as a true inflammation. It may occur in two forms anterior and posterior. The eyelid margins can become inflamed, irritated, and itchy when these glands produce abnormal secretions. Blepharitis is often seen in patients with acne rosacea, a generalized illness of oil glands. Anterior blepharitis is due to inflammation of the lid margin around the lashes. Seborrhoeic blepharitis is similar to dandruff of the scalp. Staphylococcal blepharitis is a result of bacterial infection of the lashes. Allergies due to reactions from mascara, contact lens solutions, and sprays, exposure to animals, environmental chemicals, or airborne allergens can also cause blepharitis.&#x0D; The single most important treatment principle is a daily routine of good eyelid hygiene ,this includes frequent scalp and face washing, using warm compresses to soak the eyelids, and doing eyelid scrubs but these treatment have very little efficacy in chronic and severe blepharitis. Antibiotic oral and ointment are also prescribed to decrease the bacterial load, other treatment modalities like artificial tear for dry eye and topical antibiotics are used in cases of severe inflammation. Topical antibiotics are recommended to decrease the bacterial load, and topical corticosteroids may help in cases of severe inflammation. Azithromycin ophthalmic solution 1% in Durasite has been proposed as a novel treatment for posterior blepharitis. &#x0D; In this review I shall focus on Azithromycin 1% ophthalmic solution for the treatment of blepharitis based on its good anti-infective, anti-inflammatory and good tissue penetration.

Topical Azithromycin and Oral Doxycycline Therapy of Meibomian Gland Dysfunction

Meibomian gland dysfunction (MGD) is a common clinical problem that is often associated with evaporative dry eye disease. Alterations of the lipids of the meibomian glands have been identified in several studies of MGD. This prospective, observational, open-label clinical trial documents the improvement in both clinical signs and symptoms of disease as well as spectroscopic characteristics of the meibomian gland lipids after therapy with topical azithromycin ophthalmic solution and oral doxycycline treatment. Subjects with symptomatic MGD were recruited. Signs of MGD were evaluated with a slit lamp. Symptoms of MGD were measured by the response of subjects to a questionnaire. Meibum lipid-lipid interaction strength, conformation, and phase transition parameters, and meibum protein content were measured using Fourier transform infrared spectroscopy and principal component analysis. Terpenoids, short-chain CH3 moieties, lipid oxidation, wax, cholesterylesters and glycerides were measured with a proton nuclear magnetic resonance (H-NMR) spectrometer. Topical therapy with azithromycin and oral therapy with doxycycline relieved signs and symptoms and restored the lipid properties of the meibomian gland secretion toward normal. Compared with 4 weeks of azithromycin treatment reported in our previous study, oral doxycycline treatment was slightly less effective in improving foreign body sensation and the signs of plugging and secretion. In subjects with clinical evidence of MGD, changes in ordering of the lipids and phase transition temperature were brought closer to normal with azithromycin treatment than doxycycline treatment. Treatment with doxycycline but not azithromycin restored the Fourier transform infrared spectroscopy-principal component analysis scores and relative area of the H-NMR resonance at 1.26 ppm. Both doxycycline and azithromycin treatment restored the levels of the relative areas of the H-NMR resonance at 5.2 and 7.9 ppm to normal levels. The levels of meibum protein and meibum lipid oxidation were not influenced by azithromycin or doxycycline treatment. The mechanism of action of doxycycline may be different from that of azithromycin in therapy of MGD. It is notable that when carotenoids in meibum are low, as in MGD, the tear film is unstable and patients have the signs and symptoms of dry eyes. When carotenoids are restored with azithromycin and doxycycline treatment, tear film stability is restored and patients no longer have the signs and symptoms of dry eyes.

Azithromycin 1.5% ophthalmic solution: efficacy and treatment modalities in chronic blepharitis.

To assess the efficacy of topical 1.5% azithromycin in the treatment of moderate to severe chronic blepharitis and to compare the efficacy of two different treatment modalities. A randomized clinical trial included 67 patients with chronic anterior and/or posterior blepharitis, followed-up for 3 months. Signs and symptoms were graded according to severity. Patients were randomized into two groups: 33 patients in group I and 34 patients in group II. Group I patients were treated with topical 1.5% azithromycin twice a day for three days, and Group II patients were treated with topical 1.5% azithromycin twice a day for three days then at bedtime for the rest of the month. All patients were instructed to apply warm compresses and an eye-friendly soap twice daily. Patients in both groups tolerated the treatment with minimal irritation. A significant improvement in signs and symptoms was noted at the one week follow-up visit. Group II showed a more pronounced and longer-lasting improvement that persisted after three months of follow-up. Topical 1.5% azithromycin ophthalmic solution is an effective treatment option for chronic blepharitis. In moderate to severe blepharitis, a one month treatment is safe and shows better improvement than the three-day protocol with no significant relapse until three months of follow-up.

Safety and Efficacy of Topical Azithromycin Ophthalmic Solution 1.0% in the Treatment of Contact Lens–Related Dry Eye

The purpose of this pilot study was to evaluate the safety and efficacy of azithromycin ophthalmic solution 1% in patients with contact lens-related dry eye (CLDE). This was a 4-week, single-center, open-label clinical trial in patients diagnosed with CLDE using the Contact Lens Dry Eye Questionnaire (CLDEQ). Fifty patients were enrolled in this study. The patients were randomized to 1 of 2 treatment groups: azithromycin ophthalmic solution administered bid on days 1 and 2 and on days 3 to 29±1 or Visine for Contacts rewetting drops administered qid on days 1 to 29±1. The patient diaries were used daily to collect data on comfortable and total contact lens wear time and ocular dryness throughout the treatment period. Tear osmolarity, fluorescein corneal staining, and visual acuity were also assessed during clinic visits. Fifty patients were enrolled, and 44 completed the study. One patient discontinued in the azithromycin group, and five patients discontinued in the rewetting drops group because of adverse events. A statistically significant increase in mean comfortable contact lens wear time from baseline was observed for the subjects treated with azithromycin ophthalmic solution as compared with the subjects treated with rewetting drops at week 4 (P=0.004; primary endpoint), in addition to weeks 2 and 3. The improvement in the mean comfortable wear time for the patients in the azithromycin treatment group exceeded 2 hrs throughout the treatment period (weeks 1-4). No significant differences were observed between the groups for total wear time, low contrast visual acuity, or tear osmolarity. Subject-rated ocular dryness (PM time assessments) was significantly improved from baseline in the subjects treated with azithromycin ophthalmic solution as compared with those treated with rewetting drops at weeks 2 and 3 endpoints (P=0.015 for each week). Additionally, a statistical difference was observed in favor of the azithromycin treatment group at week 2 for the subjects reclassifying as nondry eye as determined by the CLDEQ (P=0.05). Treatment with topical azithromycin ophthalmic solution was well tolerated and resulted in a significant improvement in comfortable contact lens wear time in the patients with CLDE.

Update and critical appraisal of the use of topical azithromycin ophthalmic 1% (AzaSite&amp;reg;) solution in the treatment of ocular infections

Azithromycin is an azalide that acts by binding to the 50S ribosomal subunit of susceptible microorganisms and interfering with microbial protein synthesis. Azithromycin is also noted by anti-inflammatory and immunomodulatory activity. AzaSite® (Inspire Pharmaceuticals, Inc, Durham, NC) is azithromycin ophthalmic solution, 1% formulated in polycarbophil (the aqueous mucoadhesive polymer contained in DuraSite®) that delivers high and prolonged azithromycin concentrations in a variety of ocular tissues, including the conjunctiva, cornea and particularly the eyelid. AzaSite was approved by the Food and Drug Administration (FDA) in the US in 2007, for the treatment of bacterial conjunctivitis caused by susceptible isolates. This article aims to evaluate the peer-reviewed published scientific literature and to define well-established uses of AzaSite eye drops in the field of ocular infections.

Evaluation of clinical efficacy and safety of tobramycin/dexamethasone ophthalmic suspension 0.3%/0.05% compared to azithromycin ophthalmic solution 1% in the treatment of moderate to severe acute blepharitis/blepharoconjunctivitis

Objective:To evaluate the clinical efficacy and safety of tobramycin/dexamethasone (TobraDex ST; ‘ST’) ophthalmic suspension 0.3%/0.05% compared to azithromycin (Azasite) ophthalmic solution (1%) in the treatment of moderate to severe blepharitis/blepharoconjunctivitis.Research design and methods:The study was a multicenter, randomized, investigator-masked, and active-controlled, 15-day study. Enrolled in the study were 122 adult subjects (at least 18 years of age) diagnosed with moderate to severe blepharitis/blepharoconjunctivitis, defined by a minimum score of at least ‘1’ for one of the lid signs, one of the conjunctival signs, and one of the symptoms in at least one eye and a minimum global score (total signs and symptoms score) of ‘5’ in the same eye. One group of 61 subjects received ST with instructions to dose 1 drop four times daily (QID) for 14 days. The other group of 61 subjects received azithromycin and dosed with 1 drop twice daily (BID) for 2 days followed by once daily (QD) dosing for 12 days. Visits were conducted at Day 1 (baseline), Day 8 and Day 15. The a priori primary outcome parameter of the study was the seven-item global score defined as the total score of lid margin redness, bulbar conjunctival redness, palpebral conjunctival redness, ocular discharge (0–3 scale), and lid swelling, itchy eyelids, and gritty eyes (0–4 scale). The study utilized standardized, validated photograph control scales developed by Ora, Inc. (Andover, MA).Clinical trial registration:Trial registration: ClinicalTrials.gov identifier: NCT01102244.Results:A statistically significant lower mean global score (p = 0.0002) was observed in subjects treated with ST compared to subjects treated with azithromycin at Day 8. No serious adverse events were reported during the course of the study in either group.Conclusion:ST provides a fast and effective treatment of acute blepharitis compared to azithromycin. Initial therapy with the combination of tobramycin/dexamethasone provides faster inflammation relief than azithromycin for moderate to severe blepharitis/blepharoconjunctivitis.

Pharmacokinetics of Azithromycin and Moxifloxacin in Human Conjunctiva and Aqueous Humor During and After the Approved Dosing Regimens

To evaluate the ocular pharmacokinetics of azithromycin and moxifloxacin in human conjunctiva and aqueous humor in subjects undergoing cataract surgery. Multicenter, open-label, randomized study. Subjects scheduled for routine cataract surgery and with normal-appearing conjunctiva were eligible. One conjunctival biopsy sample and 1 aqueous humor sample were obtained from subjects randomly assigned to 1 of 10 prespecified time points (1 to 312 hours) after treatment initiation of azithromycin ophthalmic solution 1% or moxifloxacin ophthalmic solution 0.5%. Samples were assayed using liquid chromatography tandem mass spectrometry. Azithromycin 1% provided high concentrations (peak level, 559.7 μg/g) in human conjunctiva that were sustained at levels 1 to 2 orders of magnitude higher than those of moxifloxacin 0.5% throughout the 7-day dosing period and for at least 7 days thereafter. Azithromycin also showed an extended half-life (65.7 hours) in conjunctiva relative to that of moxifloxacin (28.6 hours). Accordingly, the concentration of azithromycin was maintained well above the minimum inhibitory concentration required for inhibition of growth of 90% of tested bacterial isolates for at least 7 days, whereas moxifloxacin conjunctival levels fell to levels at or less than the minimum inhibitory concentration required for inhibition of growth of 90% of tested bacterial isolates approximately 24 hours after the last dose. Peak aqueous humor concentration of moxifloxacin was higher (0.77 μg/mL) than that of azithromycin (0.053 μg/mL). No clinically relevant safety findings were observed. Azithromycin 1% demonstrated high, therapeutic levels in the conjunctiva that were maintained up to 7 days after completion of a 1-week dosing regimen. Aqueous humor levels, however, were subtherapeutic with this dosing regimen. In comparison, moxifloxacin achieved lower conjunctival tissue levels, but higher aqueous humor levels.

Multicenter Open-Label Study Evaluating the Efficacy of Azithromycin Ophthalmic Solution 1% on the Signs and Symptoms of Subjects With Blepharitis

To evaluate the effect of 4 weeks of treatment with azithromycin ophthalmic solution 1% on eyelid bacterial load, tear cytokines, and signs and symptoms of blepharitis. Twenty-six subjects (mean age 64.2 years; 65% female; 100% white) with moderate to severe blepharitis received azithromycin ophthalmic solution 1% in the absence of warm compresses or eyelid scrubs for 28 days (twice a day on days 1 and 2 and once a day on days 3-28). Blepharitis signs and symptoms were evaluated at baseline (day 1) and compared with end of treatment (day 29) and 2 follow-up visits (2 and 4 weeks posttreatment). Tear collection and eyelid margin bacterial cultures were performed at baseline and end of treatment. Tear cytokines were measured by a multiplex immunobead assay. Four-week azithromycin treatment demonstrated significant decreases from baseline in investigator-rated signs of meibomian gland plugging, eyelid margin redness, palpebral conjunctival redness, and ocular discharge (P < or = 0.002) at day 29, which persisted 4 weeks posttreatment (P < or = 0.006). Subject-reported symptoms of eyelid itching, foreign body sensation/sandiness/grittiness, ocular dryness, ocular burning/pain, and swollen/heavy eyelids also demonstrated significant improvement from baseline (P < 0.001 for all symptoms and time points, except P = 0.037 for ocular dryness at visit 4). Eyelid margin culture exhibited significant decreases in coagulase-negative staphylococci and Corynebacterium xerosis bacteria. Changes in tear cytokine concentrations were not observed. Twelve subjects experienced 19 adverse events, 15 of which were ocular and none of which were serious. Azithromycin provided significant improvement in signs and symptoms of blepharitis after 4 weeks of treatment compared with baseline and persisted in the 4-week follow-up period.

Azithromycin in DuraSite&amp;reg; for the treatment of blepharitis

Blepharitis is a common inflammatory disease of the eyelid. Posterior blepharitis affects the posterior lamella of the eyelid and involves inflammation of the meibomian glands, whereas anterior blepharitis affects the anterior lamella of the eyelid and the eyelashes; either version can be inflammatory or infectious in nature. Each of these conditions can incite or propagate the other; anterior blepharitis, if not treated, can lead to meibomian gland disease, and vice versa. Blepharitis is typically chronic, and can be associated with a variety of systemic diseases such as dermatitis, as well as ocular diseases such as dry eye, conjunctivitis, or keratitis. The standard treatment regimen historically consists of lid hygiene with warm compresses and eyelid scrubs, although these treatment modalities may have limited efficacy for many patients, especially those with more severe disease. Adjunctive treatment includes systemic and topical antibiotics, topical corticosteroids, and tear replacement therapy. Topical antibiotics are recommended to decrease the bacterial load, and topical corticosteroids may help in cases of severe inflammation. Azithromycin ophthalmic solution 1% in DuraSite((R)) (AzaSite((R)); Inspire Pharmaceuticals, Durham, North Carolina, USA) has been proposed as a novel treatment for posterior blepharitis, based on its well-known anti-infective profile, its anti-inflammatory properties, its excellent tissue penetration, and its regulatory approval for the treatment of bacterial conjunctivitis. This review focuses on an off-label indication for topical azithromycin 1% in DuraSite for the treatment of blepharitis.

Ocular Surface Distribution and Pharmacokinetics of a Novel Ophthalmic 1% Azithromycin Formulation

To investigate the ocular distribution of 1% azithromycin ophthalmic solution and the effect of polycarbophil-based mucoadhesive formulation on ocular tissue levels of azithromycin after single and multiple topical administrations in the rabbit eye. Rabbits were treated with either a single administration of 1% azithromycin solution with or without polycarbophil, or with multiple administrations of 1% azithromycin solution in polycarbophil. Drug concentrations were measured using LC/MS/MS. Conjunctiva, cornea, aqueous humor, and tear samples were analyzed over a period of 144 h after a single administration of azithromycin with or without polycarbophil. Eyelid, conjunctiva, cornea, aqueous humor, and tear samples were collected over a period of 288 h during and after multiple administrations of azithromycin. Azithromycin was rapidly absorbed and distributed in the ocular tissues, reaching within 5 min, concentrations of 10,539 microg/mL in tear film, 108 microg/g in conjunctiva, and 40 microg/g in the cornea. The drug demonstrated tissue-specific half-lives of 15, 63, and 67 h, respectively. Following multiple administrations, the drug gradually accumulated. The polycarbophil formulation increased the bioavailability of the drug, producing peak concentrations that were between 5- and 12-fold higher than those without polycarbophil. Azithromycin also distributed rapidly in the eyelids, reaching peak concentrations of 180 mug/g at the end of the 7-day treatment, and was eliminated with a half-life of 125 h. Six days after treatment was discontinued, eyelid levels of azithromycin were above 40 microg/g. Sustained and high concentrations were encountered with 7-day approved administration of 1% azithromycin formulation (AzaSite, Inspire Pharmaceuticals, Inc., Durham, NC) within all ocular surface tissues, particularly the lids. Many ocular surface disorders involving the tear film, eyelids, and adnexal structures are associated with chronic, low-grade bacterial infection and may potentially lead to decreased vision secondary to corneal scarring. Various topical antibiotic and steroid combinations with or without oral tetracyclines are commonly used with variable clinical response and known potential side effects. The clinical relevance of this study is unknown; however, the long-lasting antibacterial and additional anti-inflammatory properties of topical azithromycin might offer an effective alternative treatment option and should be explored further in clinical studies.

Conjunctival tissue pharmacokinetic properties of topical azithromycin 1% and moxifloxacin 0.5% ophthalmic solutions: A single-dose, randomized, open-label, active-controlled trial in healthy adult volunteers

Background: Effective ocular tissue concentrations and prolonged residence times of antibacterial agents are important in treating both acute and chronic diseases. Conjunctival biopsy allows the determination of specific tissue concentration data for topical ophthalmic agents. Drug concentration analysis at various time points following instillation allows interpretation of the residence time and a rationale for dosing frequency.Objective: This study compared the pharmacokinetic parameters of 2 currently available topical ocular antibiotics—azithromycin ophthalmic solution 1% and moxifloxacin ophthalmic solution 0.5%—in the conjunctiva of healthy volunteers after a single topical administration.Methods: This single-dose, randomized, open-label, active-controlled clinical trial was conducted at ORA Clinical Research and Development, North Andover, Massachusetts. Subjects were randomly assigned to receive a single dose of azithromycin or moxifloxacin and to undergo biopsy sampling at 30 minutes or 2, 12, or 24 hours after administration. Concentrations of azithromycin and moxifloxacin were determined using liquid chromatography tandem mass spectrometry. Adverse events (AEs) were assessed at all visits using visual acuity measurements, slit-lamp biomicroscopy, and direct questioning.Results: Forty-eight subjects (mean age, 40.0 years; 48% female; 96% white, 2% black, and 2% Asian) underwent conjunctival biopsy. Mean (SD) concentrations of azithromycin in conjunctival tissue (lower limit of quantitation [LLOQ], 1 µg/g for 1-mg biopsy specimen) were 131 (89), 59 (19), 48 (24), and 32 (20) µg/g at 30 minutes and 2, 12, and 24 hours, respectively (median values, 117, 69, 46, and 30 µg/g). Mean concentrations concentrations of moxifloxacin in conjunctival tissue (LLOQ, 0.05 µg/g for 1-mg biopsy sample) were 1.92 (2.03), 3.77 (8.98), 0.02 (0.04), and 0.01 (0.02) µg/g at 30 minutes and 2, 12, and 24 hours, respectively (median values, 1.12, 0.12, <0.05, and <0.05 µg/g). Thirteen subjects (6 in the azithromycin group and 7 in the moxifloxacin group) experienced 20 AEs, 11 of which were considered possibly related to study treatment, and 15 of which were ocular (most commonly conjunctival hemorrhage).Conclusions: In this single-dose study of 2 currently available topical ocular antibiotics in healthy volunteers, therapeutic concentrations were achieved with both agents. Both treatments were well tolerated in the population studied. Clinical Trials Identification Number: NCT00564447.

Efficacy of topical azithromycin ophthalmic solution 1% in the treatment of posterior blepharitis

Azithromycin, a broad-spectrum antibiotic with potent anti-inflammatory activities, has the potential to effectively treat blepharitis, an inflammatory disease of the eyelid with abnormal eyelid flora as an etiologic determinant. The present study compared the efficacy of topical azithromycin ophthalmic solution 1% (AzaSite; Inspire Pharmaceuticals, Inc, NC, USA) combined with warm compresses (azithromycin group) to warm compresses alone (compress group) in patients with posterior blepharitis. Twenty-one patients diagnosed with posterior blepharitis were randomized in an open-label study to receive either azithromycin plus warm compresses (10 patients), or compresses alone (11 patients). All patients were instructed to apply compresses to each eye for 5-10 minutes twice daily for 14 days. Each eye in the azithromycin group also received azithromycin solution (1 drop) twice daily for the first 2 days followed by once daily for the next 12 days. Patients were evaluated at study initiation (visit 1) and at end of treatment (visit 2) for the severity of five clinical signs: eyelid debris, eyelid redness, eyelid swelling, meibomian gland (MG) plugging, and the quality of MG secretion. At visit 2, patients also rated their degree of overall symptomatic relief. Twenty patients completed the study. At visit 2, patients in the azithromycin group demonstrated significant improvements in MG plugging, MG secretions, and eyelid redness as compared with the compress group. In the azithromycin group, MG plugging resolved completely in three patients and MG secretion returned to normal in two patients; no such results were seen in the compress group. Furthermore, a higher percentage of patients in the azithromycin group rated overall symptomatic relief as excellent or good. Visual acuity measurements and biomicroscopic evaluation revealed no ocular safety issues. Azithromycin ophthalmic solution in combination with warm compresses provided a significantly greater clinical benefit than warm compresses alone in treating the signs and symptoms of posterior blepharitis.