NALFON ®tablets is a nonsteroidal, anti-inflammatory, antiarthritic drug that also possesses analgesic and antipyretic activities. Its exact mode of action is unknown, but it is thought that prostaglandin synthetase inhibition is involved.
Results in humans demonstrate that fenoprofen has both anti-inflammatory and analgesic actions. The emergence and degree of erythemic response were measured in adult male volunteers exposed to ultraviolet irradiation. The effects of fenoprofen, aspirin and indomethacin were each compared with those of a placebo. All three drugs demonstrated antierythemic activity.
In all patients with rheumatoid arthritis, the anti-inflammatory action of NALFON has been evidenced by relief of pain, increase in grip strength and reductions in joint swelling, duration of morning stiffness and disease activity (as assessed by both the investigator and the patient). The anti-inflammatory action of NALFON has also been evidenced by increased mobility (i.e., a decrease in the number of joints having limited motion).
The use of NALFON in combination with gold salts or corticosteroids has been studied in patients with rheumatoid arthritis. The studies, however, were inadequate in demonstrating whether further improvement is obtained by adding NALFON to maintenance therapy with gold salts or steroids. Whether or not NALFON used in conjunction with partially effective doses of a corticosteroid has a “steroid-sparing” effect is unknown.
In patients with osteoarthritis, the anti-inflammatory and analgesic effects of NALFON have been demonstrated by reduction in tenderness as a response to pressure and reductions in night pain, stiffness, swelling and overall disease activity (as assessed by both the patient and the investigator). These effects have also been demonstrated by relief of pain with motion and at rest and increased range of motion in involved joints.
In patients with rheumatoid arthritis and osteoarthritis, clinical studies have shown fenoprofen to be comparable to aspirin in controlling the aforementioned measures of disease activity, but mild gastrointestinal reactions (nausea, dyspepsia) and tinnitus occurred less frequently in patients treated with fenoprofen than in aspirin-treated patients. It is not known whether fenoprofen calcium causes less peptic ulceration than does aspirin.
In patients with pain, the analgesic action of NALFON has produced a reduction in pain intensity, an increase in pain relief, improvement in total analgesia scores and a sustained analgesic effect.
Under fasting conditions, fenoprofen is rapidly absorbed and peak plasma levels of 50 mcg/mL are achieved within 2 hours after oral administration of 600 mg doses. Good dose proportionality was observed between 200 mg and 600 mg doses in fasting male volunteers. The plasma half-life is approximately 3 hours. About 90% of a single oral dose is eliminated within 24 hours as fenoprofen glucuronide and 4’ hydroxy-fenoprofen glucuronide, the major urinary metabolites of fenoprofen. Fenoprofen is highly bound (99%) to albumin.
The concomitant administration of antacid (containing both aluminum and magnesium hydroxide) does not interfere with absorption of NALFON.
There is less suppression of collagen-induced platelet aggregation with single doses of fenoprofen calcium than there is with aspirin.