Just to say, from my viewpoint as a nurse, all medication come with side effects and they don't all prove as effective in different people, even if they appear to be exhibiting very similar symptoms or share a diagnosis.
It's vital, when any medicine is taken, to be aware of the common and non-common effects of the medication as well as any interactions it might have with others or areas of the takers lifestyle.
While, ideally, the prescribing doctor should be doing this it is sometimes the case that it is a consultant in isolation from the rest of the person's clinical file that is making a call.
It's no harm asking your trusted GPs opinion also.
And always report something of concern, don't wait.
A medication is seldom the only one available, so there may be more suitable option, but only raising the concern will see the needed changes made.
Lastly, always expect a clinical decision explained in terms you can understand, and don't be fobbed off.
If you or a loved one is expected to take something that important you should expect to be informed as to the positives and negatives, as well as a review period.