Obesity is one of the cause for hypertension. But it is not the only cause for hypertension. Primary hypertension
is one which is commonest where actual cause of hypertension can't be identified. Even though you have reduced weight, hypertension could be due to genetic cause also. So the controlled blood pressure what you are having now might be due to the amlodipine
. If you stop the drug, BP may shoot up. So i suggest you to consult physician and have regular BP monitoring, then if physician is willing you can skip the drug..