indication

For the treatment of initial and recurrent urinary tract infections in adults caused by the following susceptible microorganisms: Escherichia coli, Proteus mirabilis, Proteus vulgaris, Klebsiella species (including K. pneumoniae), and Enterobacter species.

pharmacology

Cinoxacin is a synthetic antibacterial agent with in vitro activity against many gram-negative aerobic bacteria, particularly strains of the Enterobacteriaceae family. Cinoxacin inhibits bacterial deoxyribonucleic acid (DNA) synthesis, is bactericidal, and is active over the entire urinary pH range. Cross resistance with nalidixic acid has been demonstrated.

mechanism of action

Evidence exists that cinoxacin binds strongly, but reversibly, to DNA, interfering with synthesis of RNA and, consequently, with protein synthesis. It appears to also inhibit DNA gyrase. This enzyme is necessary for proper replicated DNA separation. By inhibiting this enzyme, DNA replication and cell division is inhibited.

toxicity

Oral, subcutaneous, and intravenous LD₅₀ in the rat is 3610 mg/kg, 1380 mg/kg, and 860 mg/kg, respectively. Oral, subcutaneous, and intravenous LD₅₀ in the mouse is 2330 mg/kg, 900 mg/kg, and 850 mg/kg, respectively.Symptoms following an overdose of cinoxacin may include anorexia, nausea, vomiting, epigastric distress, and diarrhea. The severity of the epigastric distress and the diarrhea are dose related. Headache, dizziness, insomnia, photophobia, tinnitus, and a tingling sensation have been reported in some patients.

biotransformation

Hepatic, with approximately 30-40% metabolized to inactive metabolites.

absorption

Rapidly absorbed after oral administration. The presence of food delays absorption but does does not affect total absorption.

half life

The mean serum half-life is 1.5 hours. Half-life in patients with impaired renal function may exceed 10 hours.