Tolerability and compliance with risedronate in clinical practice
This study by Hamilton B and others is the first that I've seen on risedronate (Actonel) showing adverse upper GI events. See: PMID: 12730745 for details. As everyone taking one of the bisphosphonates knows, when they are ingested it is supposed to be on an empty stomach (preferably before breakfast), with a full glass of water, and you are to remain upright for a minimum of one-half hour before eating--I recommend waiting longer to get the full benefit of the medication. What Hamilton and others found is that despite counseling, 25% of the patients didn't follow those instructions for taking the risedronate. And, these patients were more likely to have adverse upper GI events. Perhaps the most significant factor for those having upper GI disturbance was a history of upper GI symptoms (44% of those having problems). Of the 42 people who stopped risedronate due to symptoms, about 50% were able to continue therapy after being rechallenged with the risedronate. The authors suggest that clinic staff be assigned the duty of patient follow up to assure proper compliance with recommended procedures for taking the medication. Some points of interest: 1) Upper GI events occurred in 21% of patients. This figure is important because it almost exactly duplicates the number of people having upper GI disturbances in the clinical trial of risedronate for patients who had previously been intolerant of alendronate (Fosamax). See PMID: 11820707 by Adachi and others for details. In this study, when people unable to take Fosamax were given risedronate, 5-mg a day, for three months or given a placebo, 19.4% in the placebo group and 20% in the risedronate group had upper GI problems. When placebo and test medication give the same results, you have to conclude it isn't the test medication that is causing the problem--even though it is potentially capable of doing it. 2) Hamilton and others got a 50% improvement when patients were rechallenged after they first suffered GI problems. I don't know what percentage of the people were noncompliant when first having problems, but this could have been a significant number. And, an interesting thought would be how many people would get improvement if they were rechallenged a second or third time? I hope future trials will test that, since the results would be interesting and important. Also, there appeared to be no placebo group during the rechallenge phase. Adding that group would surely provide interesting findings in future studies.
Editor's thoughts on this issue: If you feel you are having upper GI problems due to any of the bisphosphonates, talk to your physician about that immediately. If he/she agrees, I would suggest going off the medication for two to four weeks to see if all symptoms completely subside. If they don't, have an evaluation to determine what is causing the problem, since it isn't the bisphosphonate. If the pain goes away, then I would take the medication again, keeping an open mind because the upper GI problems could have been related to many other things. If the pain returns again, I would notify my physician, and look for another medication such as Forteo or I.V. bisphosphonates to treat the osteoporosis.