General Information

Zipsor (diclofenac potassium) liquid filled capsule is a benzeneacetic acid derivative non-steroid anti-inflammatory drug. The mechanism of action of Zipsor, like that of other NSAIDs, is not completely understood but may involve inhibition of the cyclooxygenase (COX-1 and COX-2) pathways. Diclofenac’s mechanism may also be related to prostaglandin synthetase inhibition.

Zipsor is specifically indicated for the relief of mild to moderate acute pain in adults (18 years of age or older).

Zipsor is supplied as a 25mg liquid capsule designed for oral administration. The recommended initial dose is 25 mg four times a day.

Mechanism of Action

Zipsor (diclofenac potassium) liquid filled capsule is a benzeneacetic acid derivative non-steriod anti-inflammaotry drug. The mechanism of action of Zipsor, like that of other NSAIDs, is not completely understood but may involve inhibition of the cyclooxygenase (COX-1 and COX-2) pathways. Diclofenac’s mechanism may also be related to prostaglandin synthetase inhibition.

Side Effects

Adverse events associated with the use of Zipsor may include, but are not limited to, the following:

• Abdominal pain
• Constipation
• Diarrhea
• Dyspepsia
• Nausea
• Vomiting
• Dizziness
• Headache
• Somnolence
• Pruritus
• Increased sweating

The Zipsor drug label come with the following Black Box Warning: Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. Zipsor is contraindicated in the setting of coronary artery bypass graft (CABG) surgery. NSAIDs cause an increased risk of serious gastrointestinal (GI) adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These events can occur at any time during use and without warning symptoms. Elderly patients and patients with a prior history of peptic ulcer disease and/or GI bleeding are at greater risk for serious GI event.

Clinical Trial Results

The FDA approval of Zipsor was based on the results of two clinical studies. These multicenter, randomized, double-blind, placebo- controlled, parallel arm, multiple-dose clinical trials compared Zipsor 25 mg and placebo in patients with pain following bunionectomy with osteotomy. Once the criteria for randomization (pain intensity >4 on a 0-10 numerical pain rating scale) was met, the subjects received their initial dose of study medication followed by a re-medication dose when requested, and were then dosed every six hours over four days. Pain intensity was recorded at 3 and 6 hours postdose during the fixed dosing period. . In Study 1, mean baseline pain intensity scores were 6.9 in the Zipsor group (range: 4 to 10) and 7.3 in the placebo group (range: 4 to 10). In both studies, subjects treated with Zipsor had a lower mean pain intensity score over the 48-hour inpatient period following the first remedication dose.. The median time to onset of pain relief was less than one hour for Zipsor 25 mg across the clinical trials. The results from Study 2 were similar.