• Percentage of subjects reaching a BP target of 130/80 mmHg at Week 18 [ Time Frame: Baseline/Randomization to Week 18 ] [ Designated as safety issue: No ]
• Number and doses of anti-hypertensives used in the 2 treatment arms [ Time Frame: Baseline/Randomization to Week 18 ] [ Designated as safety issue: No ]
• Levels of urinary albumin and protein content and estimated glomerular filtration rate (GFR) in the 2 treatment groups [ Time Frame: Baseline/Randomization to Week 18 ] [ Designated as safety issue: No ]
• Early BP reduction from randomization achieved with the starting dose in the 2 treatment arms [ Time Frame: Baseline/Randomization to Week 1 ] [ Designated as safety issue: No ]
• Adverse Events leading to early withdrawal [ Time Frame: Screening to end of study ] [ Designated as safety issue: Yes ]
• All Adverse Events especially, edema [ Time Frame: Screening to end of study ] [ Designated as safety issue: Yes ]
• Change in index of glycemia (HbA1c) [ Time Frame: Screening to Week 18 ] [ Designated as safety issue: No ]

The study consists of a 12 week run-in period when all subjects are stabilized on a single dose of Avalide (300 mg/12.5 mg or 300mg/25mg dose) per day. After this 12 week run-in ends, subjects will be randomly assigned to start the addition of either Adalat XL or Tiazac XC for 18 weeks of treatment. Subjects will have a 1 in 2 chance of receiving the study drug Adalat XL and a 1 in 2 chance of receiving the drug Tiazac XC. An end of treatment visit will be done 18 weeks after start of study drug. The expected duration of the study is 30 weeks. The purpose of this study is to compare the change in proteinuria, through a urine test, while taking study drug until high blood pressure (BP) is reduced to near normal levels in study subjects with diabetic nephropathy and hypertension.

• Diabetic Nephropathies
• Hypertension

• Drug: Adalat XL
• Drug: Tiazac XC

Inclusion Criteria:

• >/= 18 and < 80 years old.
• Diagnosed with hypertension.
• Diagnosed with diabetes mellitus type 2 for at least 6 mths prior to entry and on stable medication for diabetes for at 1 mth prior to screening.
• Treated on ARB, ACE inhibitor with or without hydrochlorothiazide and suitable to receive combination therapy with Avalide at 300mg/12.5mg per day or 300mg/25mg per day.
• Diagnosed with diabetic nephropathy and have proteinuria between 0.8g/day and 5.0g/day at screening and then between 0.8g/day and 3.0g/day at randomization.
• Medically appropriate to receive Adalat XL or Tiazac XC.

Exclusion Criteria:

• History of alcohol or substance abuse.
• Significant CV disorder such as ischemic heart disease, arrhythmias within the last 6 mths, or any history of severe congestive heart failure.
• Myocarditis or pericarditis within last 30 day of screening.
• ECG showing evidence of major arrhythmia or conduction disturbances requiring treatment with anti-arrhythmic medication.
• Females with child-bearing potential or males with a partner of child-bearing potential unless willing to use effective contraception during the study and 3 mths after the end of study.
• Females who are pregnant, lactating or planning pregnancy during the study and for 3 mths after the study end.
• Known hypersensitivity to Adalat XL or Tiazac XC or other calcium channel blockers of the dihydropyridine class.
• Resting heart rate <50 or >110 bpm.
• Presence of secondary or malignant hypertension.
• DBP >/= 180 and/or SBP >/= 110 mmHg.