Side effects pretty similar to most drugs...
Serious but rare side effects that have been reported in patients taking VIOXX and/or related medicines have included:
Serious stomach problems, such as stomach and intestinal bleeding, can occur with or without warning symptoms. These problems, if severe, could lead to hospitalization or death. Although this happens rarely, you should watch for signs that you may have this serious side effect and tell your doctor right away.
Heart attacks and similar serious events have been reported in patients taking VIOXX.
Serious allergic reactions including swelling of the face, lips, tongue, and/or throat which may cause difficulty breathing or swallowing and wheezing occur rarely but may require treatment right away. Severe skin reactions have also been reported.
Serious kidney problems occur rarely, including acute kidney failure and worsening of chronic kidney failure.
Severe liver problems, including hepatitis, jaundice and liver failure, occur rarely in patients taking NSAIDs, including VIOXX. Tell your doctor if you develop symptoms of liver problems. These include nausea, tiredness, itching, tenderness in the right upper abdomen, and flu-like symptoms.
In addition, the following side effects have been reported: anxiety, blurred vision, confusion, decreased levels of sodium in the blood, depression, fluid in the lungs, hair loss, hallucinations, increased levels of potassium in the blood, insomnia, low blood cell counts, palpitations, pancreatitis, severe increase in blood pressure, tingling sensation, unusual headache with stiff neck (aseptic meningitis), vertigo.
More common, but less serious side effects reported with VIOXX have included the following:
Upper and/or lower respiratory infection and/or inflammation
Headache
Dizziness
Diarrhea
Nausea and/or vomiting
Heartburn, stomach pain and upset
Swelling of the legs and/or feet
High blood pressure
Back pain
Tiredness
Urinary tract infection.
These side effects were reported in at least 2% of osteoarthritis patients receiving daily doses of VIOXX 12.5 mg to 25 mg in clinical studies.