The primary objective of this trial is to demonstrate that the fixed dose combination of telmisartan 40mg + amlodipine 10mg (T40/A10) or the fixed dose combination of telmisartan 80mg + amlodipine 10mg (T80/A10) is superior in reducing blood pressure at eight weeks compared with amlodipine 10mg monotherapy (A10) in patients who fail to respond to six weeks treatment with A10.

Inclusion Criteria:

• diagnosis of essential hypertension and blood pressure not adequately controlled before informed consent (inadequate control defined as seated diastolic blood pressure (DBP) >= 95 mmHg if on existing antihypertensive treatment or seated DBP >= 100 mmHg if treatment-naïve).
• failure to respond to six weeks treatment with amlodipine 10mg. (Failure to respond defined as seated DBP >= 90 mmHg.)
• able to stop any current antihypertensive therapy without unacceptable risk to the patient.
• willing and able to provide written informed consent.

Exclusion Criteria:

• pregnancy, breast-feeding, unwilling to use effective contraception (if female of child-bearing potential).
• known or suspected secondary hypertension.
• mean seated systolic blood pressure (SBP) >=200 mmHg and/or mean seated DBP >= 120 mmHg during run-in treatment or mean seated SBP >= 180 mmHg and/or mean seated DBP >= 120 mmHg at the randomisation visit or at any time during randomised treatment.
• any clinically significant hepatic impairment or severe renal impairment bilateral renal artery stenosis or renal artery stenosis in a solitary kidney or post post-renal transplant.
• clinically relevant hyperkalaemia.
• uncorrected volume or sodium depletion.
• primary aldosteronism.
• hereditary fructose or lactose intolerance.
• symptomatic congestive heart failure.
• patients who have previously experienced symptoms characteristic of angioedema during treatment with ACE inhibitors or ARBs.
• history of drug or alcohol dependency within the six months prior to signing consent.
• concurrent participation in another clinical trial or any investigational therapy within thirty days prior to signing consent.
• hypertrophic obstructive cardiomyopathy, hemodynamically relevant stenosis of the aortic or mitral valve.
• known allergic hypersensitivity to any component of the formulations under investigation. (Includes known hypersensitivity to telmisartan or other ARBs or amlodipine or other dihydropyridine CCBs.)
• non-compliance with study medication (defined as less than 80% or more than 120%) during the open-label run-in treatment period.
• current treatment with any antihypertensive agents, whether or not prescribed for this indication, that cannot be safely stopped (investigator¿s decision) by the start of the run-in period.
• chronic administration of any medication known to affect blood pressure, other than the trial medication.
• any other clinical condition which, in the opinion of the investigator, would not allow safe completion of the protocol and safe administration of telmisartan and amlodipine.