The primary objectives of this trial is to evaluate the changes from baseline (Visit 2) in the 24-hour Ambulatory Blood Pressure Monitoring mean (relative to dose time) for diastolic blood pressure and systolic blood pressure after 8 weeks of treatment with Telmisartan 80mg/Amlodipine 5mg in patients with moderate to severe hypertension

Inclusion criteria:

1. Aged at least 18 years at the date of signing the consent form
2. For treatment-naïve patients: hypertension defined by a mean seated diastolic blood pressure (DBP) equal or more than 100 mmHg measured by manual cuff sphygmomanometry at visit 1 and 2; For pretreatment patients: hypertension defined by a mean seated diastolic blood pressure equal or more than 90 mmHg at visit 1 and equal or more than 100 mmHg at visit 2 measured by manual cuff sphygmomanometry
3. 24-hour mean diastolic blood pressure equal or more than 85 mmHg at baseline Ambulatory Blood Pressure Monitoring

Exclusion criteria:

1. mean seated systolic blood pressure equal or more than 200 mmHg and/or mean seated diastolic blood pressure equal or more than 120 mmHg
2. any clinically significant hepatic impairment
3. severe renal impairment
4. bilateral renal artery stenosis or renal artery stenosis in a solitary kidney or post-renal transplant
5. current treatment with any antihypertensive agents, whether or not prescribed for this indication, that cannot be safely stopped
6. other conditions or situations that could put potential participants at unacceptable risk due to participation in this study

8 weeks