The attempt of present course work was to study the drug monitoring in hypertensive and diabetic patients, prescribing pattern, drug interaction and adverse drug reactions and there should be close observation for the patients receiving these medicines. They are considered as co morbidities because they occur together and share the same physiology and risk factors. Hence the early and correct diagnosis and treatment is needed. The most of the anti hypertensive and antidiabetics drugs have many drawbacks on many systems if they used for long time and these medicines have to be taken for long period only.