You are right Rudi - seek professional medical advice. Unfortunately here in Aus no doctor I spoke to would give you anything unless you are currently suffering an illness. It was very annoying telling my GP my plans and getting no good advice and I had bucklies of getting a script for any meds (remember these drugs are for heart conditions, swelling of the brain, etc - they are not specifically for altitude - try explaining that to a quack). Plus drugs cost bugger all overseas compared to here.
Seek medical advice but if your Dr is unwilling to help (as in my experiences) I believe you have a responsibility to investigate further and procure the knowledge and medications that good save you if things get ugly. On a trip to Pakistan I saw a guy get very sick - stuck for a night at 6700m I was glad he had taken the intative and stocked up on drugs in Islamabad - of course he took them without the presence of a Dr - not ideal but better than the alternative...