Timur,
There are MANY medications and combinations of medications to try for headaches whether they are tension, migraines, clusters or any combination of those (much less abdominal migraines, mixed migraines, chronic daily headaches, basilar artilery migraines, hemiplegic etc)
It is good to give a medication ample opportunity to work and increase the dosage to see if that will work, but there is also a point to where you will need to get a second opinion and FIRE YOUR DOCTOR if they are not doing enough for you. Also, do research on your own...learn enough about the options available for you so you can make educated suggestions for yourself regarding treatment options and if the doctor is not open to that...walk. You pay for them, they are there to help you and you have to take and live with whatever treatment is AGREED upon. Just remember that.
I had a doctor who kept me on the same thing forever and it did nothing...that was no help...I also had one who shoved every pill in my face and several at a time, and switched them so often I had no idea what worked and what didn't. The medications didn't even have time to work...so see, neither of these were good options....There has to be a "happy medium" Where you try one and stay on it long enough to see if it works and taper off if it doesn't and then move to the next...trying one at a time so you know what works and what doesn't. I always suggest to write everything down so you don't have to try and remember it all later.
Sara