Amlodipine and Lisinopril have different mechanisms of action... These medications are prescribed depending on the status of the patient(co-morbidities or other diseases)... For example, Beta-Blockers(a class/group of anti-hypertensives) is not given to a hypertensive patient with asthma since this may exacerbate/worsen the asthma... Better a consult your doctor...
I'm assuming that your Doctor did the switching, and he/she know if there is a possibility of a problem. If you do have concerns however, ask your pharmacist. They know more about this than the doctors sometimes.