Toprol-XL and astra zeneca

Been on Toprol XL for 4 years. I am 64 with SVT and mitral valve prolapse. I was started at 50mg daily and got relief but when breakthrough SVT started the dose went up to 50mg in the AM and 25mg in the evening. I still have breakthroughs but can wait them out. I did notice that my SVT or palpitations seemed to be triggered with an imminent BM. I have been diagnosed with fibromyalgia but coincidentally....it started with severe muscle pain when I started taking Toprol XL. I wasn't told that this could be a side effect.HMMMM When my insurance was discontinued (retirement) I started taking the generic due to cost. I haven't noticed any difference between the two. I also noticed that after a SVT episode I have a increase in urination....Toprol or SVT? I also noticed that I am very aware of an increase in a feeling doom. I have had ekgs etc and my heart is in good shape otherwise.

This website may not have saved my life, but it has certainly saved my sanity. Beginning in May 2007 I was prescribed Toprol XL for a supposed heart condition. I was instructed to begin with 50 mg per day and go to 100 mg per day after 10 days. Since I already had the 50 mg tablets, I simply started taking 2 of them together when I raised the dosage. On July 25 I ran out of the 50 mg tabs and filled a prescription for 100 mg tabs. Immediately upon starting the 100 mg tabs I began experiencing side effects which increased in severity daily. By Monday July 30 I was convinced I was losing my mind. Then I discovered this website, and read that many other people had suffered in the same way. What I have trouble grasping is why the same dosage had different effects. I tolerated the 100 mg/day dose just fine when taking 2 50 mg tabs, but the 100 mg was dreadful. I've checked the pills, and both the 50 mg and 100 mg are Astra-Zeneca products, not generic. The markings, shape and size are consistent with 100 mg tabs, so I haven't been inadvertently given an overdose. I immediately backed off the dosage, and am gradually going to reduce and stop the medication. I urge anyone who is having these problems not to stop at reporting them here, but also to contact Astra-Zeneca at www.astrazeneca.com, and to report them to the FDA's Medwatch website, www.fda.gov/medwatch. It may seem fruitless to contact Astra Zeneca, but they need to be made aware of these problems.