McNEIL CLAIMING "CAFFEINE DOES NOT ENHANCE ANALGESIC EFFICACY

McNEIL CLAIMING "CAFFEINE DOES NOT ENHANCE ANALGESIC EFFICACY of any known analgesic agents" in a submission of four new studies to FDA's Tentative Final Monograph on OTC Internal Analgesics. The Tylenol maker's Nov. 13 submission was made the same week Bristol-Myers filed new clinicals purporting to show greater efficacy of combination acetaminophen/caffeine, the ingredients of Bristol's Excedrin Extra-Strength, versus acetaminophen alone in Extra-Strength Tylenol. The response by Johnson & Johnson subsidiary McNeil contains four previously unsubmitted clinical studies that "provide compelling evidence that the addition of caffeine does not enhance the efficacy of analgesic drugs," McNeil's summary states. One of the studies is a placebo-controlled, double-blind comparison of 1000 mg acetaminophen, acetaminophen 1000 mg with 130 mg caffeine and 130 mg of caffeine alone. The trial involved 164 patients with postoperative oral surgery pain, divided into four treatment groups, who each received a single dose of a treatment. The effectiveness of each treatment was judged by patient ratings of pain intensity and pain relief at a half hour and one, two, three and four hours after receiving medication, using visual and verbal analog scales. The results of the study showed no significant differences between acetaminophen and acetaminophen plus caffeine, according to McNeil. The other three studies all compared ibuprofen 200 mg, ibuprofen 400 mg, ibuprofen 200 mg plus 100 mg caffeine, ibuprofen 400 plus 200 mg caffeine, 100 mg caffeine alone, and placebo. The studies involved: 285 patients after molar extractions; 146 patients following episiotomies; and 376 patients after orthopedic surgery, respectively. Each of the double-blinded, single-dose studies divided the patients into six treatment groups and asked them to rate pain intensity and relief. In all of the studies, McNeil states, ibuprofen plus caffeine showed no advantage over the same amount of ibuprofen without caffeine. "It could be argued," McNeil adds, "that ibuprofen 400 mg and acetaminophen 1000 mg alone may be sufficiently effective that traditional pain models provide insufficient upside sensitivity to demonstrate a caffeine adjuvant effect. These models, however, should provide sufficient upside sensitivity to detect any adjuvant effect of caffeine 100 mg when combined with an ibuprofen 200 mg dose." However, "no superiority" was shown for ibuprofen 200 mg plus caffeine over 200 mg ibuprofen without caffeine, the company states. McNeil last submitted data regarding caffeine and analgesics in May of 1989, when it forwarded to FDA the results of two clinical studies, one in dental pain and one in post episiotomy pain, which the company described as demonstrating that "caffeine could not be shown to enhance the analgesic efficacy of ibuprofen."