Incidence Greater Than 1%
The following adverse reactions were observed in clinical trials and included observations from more than 2,700 patients, 594 of whom were treated for one year and 248 for at least two years.
Gastrointestinal: The most frequently reported adverse reactions associated with meclofenamate sodium involve the gastrointestinal system. In controlled studies of up to six months duration, these disturbances occurred in the following decreasing order of frequency with the approximate incidences in parentheses: diarrhea (10% to 33%), nausea with or without vomiting (11%), other gastrointestinal disorders (10%), and abdominal pain . In long-term uncontrolled studies of up to four years duration, one third of the patients had at least one episode of diarrhea some time during meclofenamate sodium therapy.
In approximately 4% of the patients in controlled studies, diarrhea was severe enough to require discontinuation of meclofenamate sodium. The occurrence of diarrhea is dose related, generally subsides with dose reduction, and clears with termination of therapy. The incidence of diarrhea in patients with osteoarthritis is generally lower than that reported in patients with rheumatoid arthritis.
Other reactions less frequently reported were pyrosis, flatulence, anorexia, constipation, stomatitis, and peptic ulcer. The majority of the patients with peptic ulcer had either a history of ulcer disease or were receiving concomitant anti-inflammatory drugs, including corticosteroids which are known to produce peptic ulceration.
Dermatologic: rash, urticaria, pruritus
Central Nervous System: headache, dizziness
Special Senses: tinnitus
Incidence Less Than 1%—Probably Causally Related
The following adverse reactions were reported less frequently than 1% during controlled clinical trials and through voluntary reports since marketing. The probability of a causal relationship exists between the drug and these adverse reactions.
Gastrointestinal: bleeding and/or perforation with or without obvious ulcer formation, colitis, cholestatic jaundice
Renal: renal failure
Hematologic: neutropenia, thrombocytopenic purpura, leukopenia, agranulocytosis, hemolytic anemia, eosinophilia, decrease in hemoglobin and/or hematocrit
Dermatologic: erythema multiforme, Stevens-Johnson Syndrome, exfoliative dermatitis
Hepatic: alteration of liver function tests
Allergic: lupus and serum sickness-like symptoms
Incidence Less Than 1%—Causal Relationship Unknown
Other reactions have been reported but under conditions where a causal relationship could not be established. However, in these rarely reported events, that possibility cannot be excluded. Therefore, these observations are listed to alert physicians.
Central Nervous System: malaise, fatigue, paresthesia, insomnia, depression
Special Senses: blurred vision, taste disturbances, decreased visual acuity, temporary loss of vision, reversible loss of color vision, retinal changes including macular fibrosis, macular and perimacular edema, conjunctivitis, iritis
Gastrointestinal: paralytic ileus
Dermatologic: erythema nodosum, hair loss