Proquin XR (ciprofloxacin hydrochloride) is the first version of ciprofloxacin with nausea and diarrhea listed as “uncommon” adverse events in its label, rather than “common” adverse events. As a class of compounds, ciprofloxacin and other fluoroquinolones are cited in literature as causing nausea and diarrhea and these types of side effects are reportedly the most frequent reason that patients discontinue ciprofloxacin treatment.
According to Depomed’s own dissolution studies, Bayer’s Cipro and generic equivalents release their entire dosage within approximately 30 minutes and even once-daily Cipro XR releases its dosage within approximately two hours, while Proquin XR is designed to gradually release the drug over six hours.
This extended release avoids large quantities of drug remaining in the patient’s intestinal system, where it can cause side effects or interactions with gastrointestinal drugs. In a randomized, double-blind, phase III clinical trial of 1,037 patients with uncomplicated urinary tract infections (UTIs), Proquin XR eradicated the bacteria most commonly responsible for causing UTIs comparably to twice-daily Cipro.
Depomed’s new drug application (NDA) for Proquin XR was submitted in July 2004. The market for ciprofloxacin is estimated at $1.5 billion, with prescriptions for uncomplicated UTI’s representing a significant portion of usage. Depomed is currently in the final stages of negotiations with potential marketing partners for Proquin XR.