Drug Interactions between piroxicam and Synalgos-DC

GENERALLY AVOID: The use of piroxicam in combination with another nonsteroidal anti-inflammatory drug (NSAID) may increase the risk of serious and potentially fatal gastrointestinal (GI) toxicity, including inflammation, bleeding, ulceration, and perforation of the esophagus, stomach, or intestines. These events can occur at any time during NSAID use, with or without warning symptoms, but the incidence may increase with dosage and duration of therapy. Administration of piroxicam at dosages greater than 20 mg per day carries an increased risk of GI side effects, and evidence from observational studies suggests that piroxicam may also be associated with a higher risk of serious GI toxicity relative to other NSAIDs. In clinical trials of several months to two years duration, NSAID-associated upper GI ulcers, gross bleeding, or perforation occurred in approximately 1% of patients treated for 3 to 6 months and in 2% to 4% of patients treated for one year. Patients with a prior history of peptic ulcer disease and/or GI bleeding have a greater than 10-fold increased risk of developing a GI bleed during NSAID use compared to patients without a history. Additional risk factors include advanced age (especially over 70 years), Helicobacter pylori infection, excessive alcohol use, smoking, a history of GI inflammatory conditions, advanced liver disease, coagulopathy, and poor general health status. GI toxicity aside, clinical studies have also failed to demonstrate greater therapeutic benefit from the coadministration of piroxicam with another NSAID than the use of piroxicam alone.

MANAGEMENT: Concomitant use of piroxicam with other NSAIDs, except for low-dose aspirin for cardiovascular prophylaxis, should generally be avoided. Patients treated with a NSAID should be advised to take it with food and to immediately report signs and symptoms of GI ulceration or bleeding such as severe abdominal pain, dizziness, lightheadedness, and the appearance of black, tarry stools. The lowest effective dosage should be used for the shortest possible duration. Selective use of prophylactic anti-ulcer therapy (e.g., misoprostol, proton pump inhibitors) may be considered in high-risk patients.

One study has reported that coadministration of caffeine and aspirin lead to a 25% increase in the rate of appearance and 17% increase in maximum concentration of salicylate in the plasma. A significantly higher area under the plasma concentration time curve of salicylate was also reported when both drugs were administered together. The exact mechanism of this interaction has not been specified. Physicians and patients should be aware that coadministration of aspirin and caffeine may lead to higher salicylate levels faster.