I have found some interesting information on the BHF Website, I was already a member years before my condition presented and raised a few £'s, Ironically selling cakes!
bhf.org.uk/informationsuppo...
After a couple of weeks taking Amlodipine I think that I must be a Codeine Phosphate Junky and that this is the cause of my Headaches, most mornings.
Please do not reply and tell me to see my doctor I am and I will but I have just bought a new batch. They are very effective for me apart from the side effects!