Unexpected side effects symptoms and conditions

Prescribed Avelox 400 mg for 10 days, to combat sinusitis and lung congestion bordering on pneumonia. Dr. suggested taking it with Mucinex to increase impact on sinuses. Took first pill Monday, 4/13 and didn't have any unexpected side effects. Took 2nd pill Tuesday morning along with Mucinex, pretty much on an empty stomach, with too little liquid. I was having slight headaches, jitters, mild inability to focus, and some buzzing in my ears. After a few hours, I thought it would be safe to take an Aleve to work on the headache. BAD MOVE on my part. Within 10 - 15 minutes, I was violently ill, vomiting everything from an essentially empty stomach. I called my Dr. but he didn't return my call for a few hours. When we talked, I related the episode, and he advised that we should change medications. As we talked, I thought that maybe I had not been careful enough. Maybe there was a magnifier effect from the Avelox, the empty stomach, too little water, the Mucinex, and then adding the Aleve to the mixture. Bottom line, we decided that I'd take it again today, and be careful to avoid the combination issue. So far, it seems to be working. I'm still experiencing the buzzing ears, slight agitation/nervousness, and slight headache, but nothing scary.

There is one thing, though, that also concerns me. I have a recurring inflammation of my right Achilles heel tendon, and this illness or drug treatment brought it on big-time. My right Achilles is extremely painful and is throbbing like crazy. I normally take a Motrin (anti-inflammatory) and it goes away, but I'm not taking a chance with that until I stop the Avelox. My Patient Prescription Information makes a big deal about possible Tendon damage for those over 60, and I'm just about there.

Interesting counter-effect is that instead of not being able to sleep, I slept much better even after the first pill.

Here is an example of the fact that the medical community recognizes that there are gene based drugs. Because Singulair is modeled to be a receptor antagonist to the cysLT1 receptor and the cysLT1 receptor is a gene, I'd say that Singulair should be described as a gene based drug. I don't really care how anybody wants to play with the definition. CysLT1 is a gene with known variations. Why isn't there just an "across the board" warning for all gene based drugs that unexpected side effects are possible???? And, that doctors should watch out for individual reactions.

WMJ. 2005 Aug;104(6):61-6.Links
Gene-based drug prescribing: clinical implications of the cytochrome P450 genes.Musana AK, Wilke RA.
Department of General Internal Medicine, Marshfield Clinic, WI, USA.

The Institute of Medicine recently mandated an increased effort to improve patient safety and reduce medical error. With the description of genetic polymorphisms in the drug metabolizing enzymes, the field of pharmacogenetics may improve medical care through a reduction in both therapeutic failure and adverse drug reaction. Investigators at the Marshfield Clinic in central Wisconsin are piloting the process of gene-based drug prescribing in a variety of contexts. This paper reviews the field of cytochrome P450 (CYP) genetics and explores factors that impact the utility of this information in clinical practice.

PMID: 16218319