I think there are cultural differences here. Your English is fine, as are Naomi's examples. But, ..
Personally, I'd discuss the reasons with a doctor, rather than dictate what you want as the solution. You should jointly come to a solution about what to do.
Naomi's answers are from the perspective of someone who knows what the problem is and knows what the answer is: that is someone who is effectively self-medicating. Hence
I have a question or two regarding my medication.
I have recently ..... had headache, .....
Perhaps the dose needs adjusting.
or Could we experiment with a changed dose?
This medication is quite expensive, is there a cheaper generic brand available?
Perhaps this present medication has an alternative?