I use the PDR all the time -- I'd be lost without it -- but this is a book that's easy to MIS-use. Much of the material is tough-going, such as how the medications work and how they may interact. To some extent this is unavoidable, but......even after all these years, the publisher hasn't figured out that some aspects of the format are quite poor. For example, what would be so hard about putting things like "half-lives" of medications in tabular form, or some other "eye-friendly" thing, so they could be seen at a glance??? And in general, if you're looking for a particular thing, even if you land on the right paragraph there's a good chance you won't see it. Also, for some reason, the side effects for any given medication are divided between two or more different sections of the article.
Most astonishingly, despite the fact that the PDR tends to list anything and everything as a possible side effect for every medication, some common side effects are simply not mentioned at all. And, oftentimes some of the major uses for a given medication are not mentioned. These two problems aren't the fault of the publisher; the first reflects failures of the medical literature in general and the second reflects the fact that many correct usages of medications are not officially approved. Also the listed dosage ranges are sometimes too limited; lower or higher dosages may be right for some people.
So, don't regard the PDR as the last word. Above all, don't take too seriously the endless lists of possible side effects. Remember that these aren't necessarily things that WILL happen; they MIGHT happen. And remember that the lists usually include a lot of things that rarely if ever happen -- yet sometimes fail to include things that DO happen. If you are convinced that a medication has done something to you, and the effect is NOT mentioned in the PDR, you're still probably right. But, don't assume that something IS happening just because it IS mentioned in the PDR!