Antibacterial drugs

Lomefloxacin hydrochloride is administered orally. Lomefloxacin hydrochloride may be administered without regard to meals. Food decreases the rate of GI absorption of the drug, but only decreases the extent of absorption by 12%. Dosage of lomefloxacin, which is available for oral use as the hydrochloride, is expressed in terms of lomefloxacin.

Gemifloxacin is used for the treatment of acute bacterial exacerbation of chronic bronchitis caused by susceptible strains of Streptococcus pneumoniae, Haemophilus influenzae, H. parainfluenzae, or Moraxella catarrhalis. In several randomized, double-blind, active-controlled studies in patients with acute exacerbation of chronic bronchitis, clinical response (defined as sufficient improvement in or resolution of signs and symptoms at day 13-24 without further need for anti-infectives) was achieved in 86-94% of those receiving oral gemifloxacin (320 mg once daily for 5 days) and in 93, 85, or 85% of those receiving oral amoxicillin and clavulanate potassium (500 mg of amoxicillin 3 times daily for 7 days), oral clarithromycin (500 mg twice daily for 7 days), or oral levofloxacin (500 mg once daily for 7 days), respectively. In several controlled and uncontrolled studies in patients with clinically and radiographically documented CAP, clinical response was achieved in 89-92% of patients receiving oral gemifloxacin (320 mg once daily) for 7 days.

Pharmacokinetic interaction (decreased absorption of gemifloxacin). Gemifloxacin should be taken at least 2 hours before or 3 hours after antacids that contain aluminum or magnesium. (See Dosage and Administration: Administration.) Antacids containing calcium or calcium supplements have no clinically important pharmacokinetic interaction with gemifloxacin. Didanosine Pharmacokinetic interaction; didanosine chewable/dispersible buffered tablets, buffered powder for oral solution, or pediatric powder for oral solution prepared as an admixture with antacid may substantially decrease gemifloxacin absorption.

Gemifloxacin Mesylate: Cautions. Musculoskeletal Effects, Nervous System Effects, Sensitivity Reactions, Major Toxicities Dermatologic Reactions, Hepatic Effects, Specific Populations Pregnancy Category C. Lactation.

The oral LD50 of the drug is greater than 5 g/kg in mice and rats and approximately 2.5 g/kg in rabbits. In mice, rats, rabbits, and dogs, significant toxicity (including tonic/clonic convulsions) was observed with IV ciprofloxacin doses between 125 and 300 mg/kg.

In vitro on a weight basis, the activity of ciprofloxacin is approximately equal to or slightly greater than that of ofloxacin against most susceptible organisms and is at least 2 times greater than that of norfloxacin against most susceptible organisms. Ciprofloxacin is active in vitro against most gram-negative aerobic bacteria, including Enterobacteriaceae and Pseudomonas aeruginosa. Ciprofloxacin also is active in vitro against many gram-positive aerobic bacteria, including penicillinase-producing, nonpenicillinase-producing, and oxacillin-resistant staphylococci (previously known as methicillin-resistant staphylococci), although many strains of streptococci are relatively resistant to the drug. The drug generally is less active against gram-positive than gram-negative bacteria.

Ciprofloxacin generally is well tolerated, and adverse effects of the drug are similar to those reported with other quinolone anti-infectives (e.g., norfloxacin, ofloxacin). Adverse effects have been reported in 5-14% of patients receiving ciprofloxacin, and have been severe enough to require discontinuance in 2-3.5% of patients.

Ciprofloxacin also is used orally for the treatment of acute sinusitis, uncomplicated cervical and urethral gonorrhea, typhoid fever, and GI infections caused by susceptible bacteria. Ciprofloxacin is used in conjunction with metronidazole for the treatment of complicated intra-abdominal infections caused by E. coli, Ps. aeruginosa, P. mirabilis, K. pneumoniae, or Bacteroides fragilis. Because ciprofloxacin is inactive against most anaerobic bacteria, the drug is ineffective in and should not be used alone if a mixed aerobic-anaerobic bacterial infection is suspected. IV ciprofloxacin is used in conjunction with IV piperacillin sodium (no longer commercially available in the US as a single-entity preparation) for empiric anti-infective therapy in febrile neutropenic patients.

Adverse effects reported with ticarcillin disodium and clavulanate potassium are similar to those reported with ticarcillin alone. For information on adverse effects reported with ticarcillin and other extended-spectrum penicillins, see Cautions in the Extended-Spectrum Penicillins General Statement 8:12.16.16. Rash, pruritus, urticaria, and fever have been reported with ticarcillin disodium and clavulanate potassium.

Vials of ticarcillin disodium and clavulanate potassium labeled as containing a combined potency of 3.1 g of the drugs are reconstituted by adding approximately 13 mL of sterile water for injection or sodium chloride injection to provide a solution containing approximately 200 mg of ticarcillin per mL and 6.7 mg of clavulanic acid per mL. The vial should be shaken until the drug is dissolved.