G e m i f l o x a c i n 320mg
Each film coated tablet contains
Gemifloxacin (as Mesylate).........320mg
Gemix (Gemifloxacin) is a synthetic broad spectrum antibacterial agent for oral administration. Gemifloxacin is related to the fluoroquinolone class of antibiotics available as the mesylate salt in the sesquihydrate form. Chemically, gemifloxacin is (R,S)-7-[(4Z)-3-(aminomethyl)-4-(methoxyimino)-1pyrrolidinyl]-1 1-Cyclopropy-6-fluoro-1,4-dihydro-4oxo-1,8-naphthyridine-3-carboxylic acid (C18H20FN504CH4O3S.)
Its unique structure confers enhanced activity against gram +ve pathogens without significant compromising gram -ve & atypical pathogens activity as compare to other fluoroquinolones.
Mechanism of Action
Gemix inhibits two specific anzymes, DNA gyrase and DNA topoisomerase IV, which aid in bacterial DNA replication. Gemix displays strong binding affinity at both of these target sites, which helps maintain high potency against resistant S, Pneumoniae, This dual targeting with Gemix is achievable at therapeutic drug levels.
The pharmacokinetics of Gemix are approximately linear over the dose range from 40mg to 640mg. There was minimal accumulation of Gemix following multiple oral doses up to 640mg a day for 7 days (mean accumulation ≤20%). Following repeat oral administration of 320mg Gemix once daily, steady-state is achieved by the third day of dosing.
Absorption and Bioavailability
Gemix is rapidly absorbed from the gastrointestinal tract. Peak plasma concentrations of Gemix were observed between 0.5 and 2 hours following oral tablet administration and the absolute bioavailability of the 320mg tablet averaged approximately 71% (95% CI 60%-84%). Following repeat oral doses of 320mg to healthy subjects, The mean ± SD maximal Gemix plasma concentrations (Cmax) and systemic drug exposure (AUC(0-24) were 1.61± 0.51µg/ml (range 0.70-2.62 µg/ml) and 9.93 ± 3.07 µg/ml (range 4.71-20.1 µg/ml). respectively. In patients with respiratory and urinary tract infections (n=1423), similar estimates of systemic drug exposure were determined using a population pharmacokinetics analysis (geometric mean AUC (0-24). 8.36 µg/ml; range 3.2-47.7 µg/ml. The pharmacokinetics of Gemix were not significantly altered when a 320mg dose was administered with a high-fat meal. Therefore Gemix tablet may be administered without regard to meals
In vivo, plasma protein binding in healthy elderly and young subjects ranged from 55% to 73% and was unaffected by age. Renal impairment dose not significantly affect the protein binding of Gemix. The blood-to-plasma concentration ratio of Gemix wa 1.2:1 Gemix is widely distributed throughout the body after oral administration. Concentrations of Gemix in bronchoalveolar lavage fluid exceed those in the plasma. Gemix penetrates well into lung tissue and fluids. After five daily doses of 320mg Gemix concentrations in plasma, bronchoalveolar macrophages, epithelial lining fluid and bronchial mucosa at approximately 2 hours.
Tissues Concentration (Mean ±SD) Ratio vs Plasma (Mean ±SD)
Plasma 1.40(0.442)µg/ml -------
Bronchoalveolar Macrophages 107 (77)µg/g 90.54(106.3)
Epithelial Lining fluid 2.69(1.96)µg/mL 1.99(1.32)
Bronchial Mucosa 9.52 (5.15)µg/g 7.21(4.03)
Gemix is metabolized to a limited extent by the liver. The unchanged compound is the predominant drug-related component detected in plasma (approximately 65%) up to 4 hours after dosing. All metabolites formed are minor (