Depomed and Esprit Pharma's Proquin XR

Depomed Inc and Esprit Pharma haveentered a license agreement for ProquinXR, a prolonged-release formulation ofciprofloxacin hydrochloride. Proquin XRis indicated for the treatment of uncomplicatedurinary tract infections.¹

Ciprofloxacin and other fluoroquinolonedrugs are noted to cause gastrointestinal(GI) side effects such as nauseaand diarrhea. In some cases, these sideeffects are reported as so severe thatpatients choose to discontinue treatmentwith the medication. Nausea anddiarrhea with Proquin XR, however, weredescribed in clinical trials as uncommon.Depomed credits Proquin XR's lengthydissolution time of 6 hours—comparedwith 30 minutes with regular-releaseciprofloxacin and 2 hours with CiproXR—as being responsible for thedecreased GI side effects. According tothe manufacturer, the extended releasetime results in a gentler effect on thepatient's intestinal system.²

Treatment with Proquin XR consistsof a 3-day regimen of a once-daily 500-mg tablet. Proquin XR is indicated onlyfor uncomplicated urinary tract infectionswith cultures or epidemiologythat suggests Escherichia coli orKlebsiella pneumoniae as the responsibleorganisms. Proquin XR should notbe used to treat pyelonephritis, complicatedurinary tract infections, or otherinfections.³

Mechanism of Action

Proquin XR inhibits the topoisomeraseresponsible for bacterial DNAreplication, transcription, repair, andrecombination. Its resulting activity isbroad-spectrum against both gramnegativeand gram-positive bacteria.³

Clinical Trials

Proquin XR was evaluated in a clinicaltrial of 1037 patients with uncomplicatedurinary tract infections. The randomized,double-blind, phase 3 clinical trial comparedonce-a-day Proquin XR with immediate-release ciprofloxacin 250 mg twicea day for 3 days. Success rates and bacteriologiceradication were comparablein both groups.^2,3

Contraindications,Warnings, andPrecautions

Proquin XR is contraindicated inpatients with a known hypersensitivity tociprofloxacin or any of the fluoroquinoloneagents.

Proquin XR should be avoided inpatients <18 years old, pregnant women,and lactating women, because its safetyin these populations has yet to be established.Ciprofloxacin and other fluoroquinoloneshave been associated withconvulsions, increased intracranial pressure,and toxic psychosis. Cautious use isadvised in patients with known or suspectedcentral nervous system disorders.Some patients using fluoroquinoloneshave experienced tendon ruptures.Elderly patients and/or patients using corticosteroidsmay be at increased risk.

Concurrent use of theophylline withProquin XR should be avoided, becausethe combination has resulted in fatalreactions. Proquin XR also may interactwith antacids, caffeine, calcium products,probenecid, warfarin, glyburide, phenytoin,sucralfate, or didanosine.

The use of Proquin XR in patients withsevere renal failure has not been studied.Dose adjustment, however, is not neededfor patients with mild-to-moderaterenal impairment. Similarly, Proquin XRhas not been evaluated in patients withacute hepatic insufficiency, but patientswith chronic stable cirrhosis do not needan adjusted dose of Proquin XR.³

Patient Counseling

Proquin XR should be taken oncedaily at about the same time for 3 days.Patients should take it with theirevening meal or their largest meal ofthe day. Proquin XR tablets should beswallowed whole and never split,crushed, or chewed. Patients shouldavoid taking this drug at the same timeas aluminum- or magnesium-containingantacids, sucralfate, didanosine(Videx) chewable buffered tablets orpediatric powder, iron or calcium supplements,or zinc preparations.

Additionally, Proquin XR may be associatedwith an increased effect from caffeinedue to caffeine accumulation.Patients may want to avoid or limit caffeineproducts while using Proquin XR.³

The most frequently reported sideeffects with Proquin XR are headache andvaginal yeast infection. Other less commonside effects include nausea, diarrhea,dizziness, and abdominal pain.^2,3

Dr. Holmberg is a pharmacist withPhoenix Children's Hospital, Phoenix,Ariz.

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