Dextromethorphan Combine With Amlodipine Treatment in Patients With Hypertension (DMTA07)

Inclusion Criteria:

1. Male or female patient aged between 50 to 75 years old (both included);

2. Patient with mild to moderate essential hypertension at enrollment, which defined as the following:

   Patient must have mean sitting SBP ≥140 and <180 mmHg or mean sitting DBP ≥90 and <110 mmHg at enrollment;

3. Patient with normal serum potassium;
4. Patient or his/her legally acceptance representative has signed the written informed consent form.

Exclusion Criteria:

1. Patient with severe hypertension (mean sitting DBP ≥ 110 mmHg or mean sitting SBP ≥ 180 mmHg);
2. Patient with secondary hypertension, such as coarctation of aorta, hyperaldosteronism, unilateral or bilateral renal artery stenosis, Cushing's disease, pheochromocytoma, polycystic kidney disease, etc;
3. Patient is under treatment with beta-blocker prior to enrollment;
4. A definite diagnosis or unstable of cardiovascular disease, including angina pectoris, myocardial infarction, coronary artery bypass graft, percutaneous transluminal coronary angioplasty, transient ischemic attack, stroke, arrhythmia and heart failure within 3 months before signing the written informed consent form;
5. Patient with concomitant endocrine diseases or type 1 Diabetes Mellitus;
6. Patient with type 2 Diabetes Mellitus with poor glucose control (glycosylated hemoglobin > 9% or fasting blood sugar > 250 mg/dL at enrollment) or under insulin treatment;
7. Patient with clinically unstable disease such as known collagen or auto-immune disease or other malignant disease requiring current medication;
8. Patient with bilateral renal artery stenosis, solitary kidney or post renal transplant;
9. Patient with clinically relevant hematological disease;

10. Hepatic or renal dysfunction as defined by the following parameters:

    • ALT or AST > 2 times upper limit of normal,
    • Total bilirubin > 2 times upper limit of normal,
    • Serum creatinine >2.0 mg/dl;
11. Female patient who is pregnant or lactating;
12. Patient with substance abuse (including alcohol) history for the past two years;
13. Known or suspected contraindications, including allergy to dextromethorphan or calcium channel blockers;
14. Patient received other investigational drug or device within 30 days before signing the written informed consent form;
15. Patient with any other serious disease considered by the investigator(s) not in the condition to enter the trial.