Double-blind study of the analgesic activity of fosfosal in patients with musculoskeletal and articular pain: comparison with lysine acetylsalicylate and placebo
Diaz, C.; Gassó, F.C.; Panadés, J.N.
Clinical Therapeutics 4(2): 121-126
1981
ISSN/ISBN: 0149-2918 PMID: 6794911 Document Number: 172853
Fosfosal is a new salicylic acid derivative that is highly soluble in water. Previous experimental and clinical studies have shown that fosfosal has a low toxicity and is well tolerated in the stomach. In a double-blind study, analgesic activity, gastric tolerance and side effects of fosfosal were compared with those of placebo and of acetylsalicylate of lysine (ASA-lysine) in patients with musculoskeletal and articular pain. From a total of 24 outpatients, only 19 finished the study; the other 5 patients abandoned the treatment for reasons unrelated to the medication. Each drug was administered to each patient for 10 days, according to a secret sequence previously established: fosfosal, placebo, ASA-lysine. The daily dose of fosfosal and of ASA-lysine was 1 gm and 0.5 gm, respectively, every 8 h. The patient's opinion, observer's impression, and assessment of pain severity (Huskisson test) were obtained to determine the pain relief and the overall efficacy of each treatment. The results showed a definite analgesic activity of fosfosal and ASA-lysine, clearly distinguishable from placebo. Differences of clinical efficacy between the active drugs were not established, but differences from placebo were statistically significant. The incidence of side effects, including gastric intolerance, was 32% (6 cases) with ASA-lysine but only 5% (1 case) with fosfosal. The excellent gastric tolerability and low toxicity of fosfosal observed in the previous pharmacological and clinical studies were confirmed int he present study.