Urinary tract infections

Drug Store News, Dec 11, 1989

Norfloxacin achieves high prostatic concentrations. In an uncontrolled trial 20 patients with chronic relapsing prostatitis received norfloxacin 400 mg po twice a day for 10 days. Eighty-five percent of the patients had negative cultures 30 days after the conclusion of therapy.

More controlled studies are needed to determine the true role of norfloxacin in chronic prostatitis.

Ciprofloxacin achieves excellent tissue penetration in the kidney and prostate with the drug concentration several times higher than serum.

Ciprofloxacin given 500 mg twice a day for 15 days was successful in eradicating the bacteria in 60 percent or more of the chronic prostatitis patients in which the causative agent was E. coli.

Norfloxacin, the first fluroquinolone antibiotic to be introduced into clinical use in the U.S., has emerged as a safe and effective agent for the treatment of UTI caused by susceptible strains of Enterobacteriaceae and P. aeruginosa. Clinical trials have demonstrated that oral norfloxacin is equivalent to or better than other oral antibiotics in the treatment of uncomplicated and complicated aerobic, nonbacteremic, gram negative UTI.

For uncomplicated UTI, norfloxacin is used in doses of 400 mg po bid for 7 to 10 days. Experience with norfloxacin for the treatment of chronic bacterial prostatitis is promising but remains very limited. In women with acute symptomatic bacterial cystitis or pyelonephritis norfloxacin appears to be as effective as trimethoprim-sulfamethoxazole.

Ciproflaxacin is very effective in the treatment of UTI both complicated and uncomplicated. It is effective for infections produced by a wide range of organisms. A review of 465 UTI treated with oral ciprofloxacin reported organism eradication in 91 percent of the patients in five to nine days after therapy. The dose was 250 mg po bid. UTI from multiply resistant organisms have proved to be susceptible to high-dose, prolonged therapy.

In chronic prostatitis caused by E coli, where clinical cure rates seldom exceed 30 percent ciprofloxacin eradicated the bacteria in 60 percent or more of the patients after one year of follow-up. The ciprofloxacin dose was 500 mg po bid for 15 days. Pharmacists should be aware of the interaction between this promising new drug and theophylline. Serum theophylline levels have been increased by ciprofloxacin. Studies of this interaction have demonstrated a decrease in total theophylline clearance. Patients receiving ciprofloxacin and theophylline should be monitored very closely to avoid theophylline toxicity.

Recurrent Infections

A recurrent infection will occur in 80 percent of all women with UTI within one year of antibiotic treatment. Eighty percent of these are due to a new serotype of E. coli or a new bacterial species. Single dose therapy is effective for infrequent bladder reinfections. An infrequent bladder reinfection would be infections separated by several years. Women experiencing frequent reinfections will usually benefit from prophylactic antibiotic therapy (Table 4), which is not a full dose therapy. This is cost effective in most clinical situations for women experiencing three or more recurrent infections per year.