BESIFLOXACIN
Dr.F.Dutta Majumder,
Asst Prof,Department of Pharmacology, Sri Balaji Medical College and Hospital,Chennai
Besifloxacin, a newer fluoroquinolone has been devloped for the topical treatment of ophthalmic infections. It has been anticipated to have a number of advantages over available therapies based on its structure, unique usage profile and antimicrobial properties.
In June 3, 2009, The US Food and Drug Administration (FDA) have approved besifloxacin 0.6% ophthalmic suspension for the treatment of bacterial conjunctivitis.
Fig: Chemical structure of Besifloxacin
Cilnical Pharmacology:
Emma Hittz showed that besifloxacin ophthalmic suspension (0.6%) has clinical equivalent to moxifloxacin opthalmic solution (0.5%) in the treatment of bacterial conjunctivitis. Both the drugs were administered 3 times a day for 5 days in 533 patients with bacterial conjuntivitis. Patients were evaluated over 3 study visits on day 1, 5 and 8. No significant difference in clinical resolution or bacterial eradication was observed between treatment groups on day 5 or 8. On day 8, approx. 84% of culture positive eyes in both groups demonstrated complete clinical resolution. Difference was only seen in adverse effect. Headache occurred in 1.2% of the besifloxacin group and 1.6% of the moxifloxacin group. Eye irritation was observed in 0.3% in besifloxacin and 1.4% in moxifloxacin group.
Mechanism of action:
Inhibits both bacterial DNA gyrase and topoisomerase IV. Present study ( Jin-Zhong Zhang and Keith W. Ward, 2007) shows Besifloxacin significantly inhibits cytokine production in human THP – 1 monocytes at very low concentrations. E.g, a significant inhibitory effect of besifloxacin was seen as low as 0.1mg/l on IL - 1α and at 1mg/l on G-CSF, IL-1α and IL-6.
Kinetics:
Average elimination half life following multiple dosing was estimated to be 7hrs.
Antimicrobial activity:
Active against both gram positive and gram negative bacteria, viz, Cornebacterium pseudodiptheriticum, Corynebacterium striatum, Haemophilus influenzae, Moraxella lacunata, Staphylococcus aureus, Staphylococcus epidermis, Staphylococcus hominis, Staphylococcus lugdunensis, Streptococcus mitis group, Streptococcus oralis, Streptococcus pneumoniae, Streptococcus salivarius.
Adverse effects:
Most frequently reported ocular adverse in 2% of patients was conjuntival redness. Others include blurred vision, eye pain, eye irritation, eye pruritius and headache.
Pregnancy:Placed in category C drug. Oral doses of besifloxacin upto 1000mg/kg/day were not associated with viseral or skeletal malformations in rat pups in a study of embryo-foetal development, although this dose was associated with maternal toxicity( reduced body weight gain and food consumption) and maternal mortality.
Nursing mother:Besifloxacin has not been measured in human milk, although it can be presumed to be excreted in human milk.
Paediatric use:The safety and effectiveness in infants below one year of age have not ben established.
Geriatric:No overall differences in safety and effectiveness have been observed between elderly and younger patients.
Dosage and administration:
Instill one drop in the affected eye 3 times a day, 4-12hrs X 7days.
Dosage form:
7.5ml bottle filled with 5ml of besifloxacin ophthalmic suspension, 0.6%
Precautions:
- Topical Ophthalmic use only
- Growth of resistant organisms with prolonged use
- Avoidance of contact lenses
References:
- Zhang J Z and Ward K W. Besifloxacin, a novel fluoroquinolone antimicrobial agent, exhibits potent inhibition of pro-inflammatory cytokines in humanTHP-1 monocytes. Journal of Antimicrobial Chemotherapy. October, 2007
- Besifloxacin Comparable to Moxifloxacin for Bacterial Conjunctivitis: Presented at AAO Abstract PO076
- Bausch and Lomb product monogram.
