The Management of Resistant Hypertension in Kidney Transplant Patients Using Chlorthalidone

The study involves transplant recipients presenting to the transplant Clinic Gateway 7th
floor with resistant hypertension. The initial contact will take place in the transplant
clinic study consist of approximately eight out patient visits over a 8 week period:
Screening, and follow-up visits will be conducted at the Clinical Research Services (CRS)
Unit. The Baseline (Week 1), Visit 1 Enrollment (Week 1) Day 1 and 2, Visit 2, (Week 3) Day
1 and 2, and Visit 3 End of Study, (Week 7) Day 1 and 2. Additional visits maybe required to
accommodate adverse reactions. The study will require approximately four (4) time points
where blood pressure, pulse and weight is obtained, safety blood collections approximately
2-3 tablespoons drawn by venipuncture and 24 hour urine collection periods. Home blood
pressure readings will be required at two (2) time points during the study. The subject will
be required to stop taking current medications for seven weeks, take study medication for 6
weeks and report adverse reactions and concomitant medications at each visit.

During the Enrollment visit, the subject will be identified, informed consent obtained,
demographic characteristics, past medical history, co-morbid illnesses, current medications,
and home and office blood pressures will be recorded to assess for eligibility criteria.
This data will be collected prospectively by the investigators.

Initial clinical assessment at the time of the patient's screening visit will be performed
at the outpatient testing center in the transplant clinic. A three day window will be
allowed for all visits. The following measurements will occur at this visit: Biometric
measurements: vitals ( blood pressure and pulse) body weight, EKG, Arm circumference,
confirmation of hypertension by 24-h ABPM , urine studies: 24 hour urine collection and
evaluation, safety, 8-10AM sitting upright Plasma Aldosterone/Renin Ratio, clinical safety
laboratory test: bone morphogenetic protein, Mg/phosphorus level, Parathyroid hormone,
vitamin D level and HbA1c, review and document concomitant medications, including current
furosemide prescription. Subjects who meet the inclusion criteria and none of the exclusion
criteria will start Baseline (Week 1) Measurements.

At Baseline (Week 1) the current furosemide prescription will be documented and
discontinued. This will begin the washout period. The washout period will continue for one
week. At the end of the washout period the subject will be instructions to return to the CRS
unit for Visit 1 Enrollment measurements.

Visit 1 Enrollment Measurements Week 1, Day 1, include the following measurements: Biometric
measurements: Body Weight, confirmation of hypertension by 24-h ABPM Urine studies: start 24
hour Urine collection, safety laboratory evaluations: bone morphogenetic protein , document
concomitant medications, and adverse reactions. Visit 1 Enrollment Measurements Week 1 Day 2
the subject will return the 24-hour urine collection and the 24 hour ABPM will be removed.
The study medication chlorthalidone will be started. The subject will take study medication
for 3 weeks before returning for the next study visit: Visit 2 (Week 3) Day 1 . A three day
window will be allowed.

At Visit 2 (Week 3) Day 1 and 2. Biometric measurements: Body Weight and home B/P
recordings, start 24 hour Urine collection. Review pill count for compliance, concomitant
medications and adverse reactions will be obtained. Day 2: the subject will return the
24-hour urine collection. Review study removal criteria After taking the study medication
for three weeks, the subject will return to the CRS unit for Visit 3 End of Study, (Week 7)
Day 1 and 2 Visit 3 End of Study, (Week 7) Day 1 and 2. On day 1, Biometric measurements:
Body Weight, start 24-h ABPM , Urine studies: start 24 hour Urine collection, safety
laboratory evaluations: 8-10AM sitting upright Plasma Aldosterone/Renin Ratio, collect
safety labs: bone morphogenetic protein, Mg/phosphorus level, parathyroid hormone, vitamin D
level and HbA1c, document pill count, concomitant medications, home blood pressure readings
and adverse Reactions. Day 2: the subject will return the 24-hour urine collection and the
24 hour ABPM will be removed If blood pressure is adequately controlled on study medication
subject may continue study medication. If blood pressure not adequately controlled on study
medication the subject may return to pre-study medication or a medication prescribed by
physician.

Inclusion Criteria:

1. Agree to participate in study

2. Patients after kidney transplantation> 6 months post-transplant.

3. Age>18 years

4. Home or office Systolic Blood pressure >140 confirmed with daytime 24-h ABPM of
average systolic blood pressure >140.

5. Tacrolimus/Cyclosporine therapy with therapeutic trough level based upon historical
values

6. Stable renal function for at least 3 months before enrollment.

7. Historical Baseline estimated Glomerular Filtration Rate >30mL/min

8. No more than trace edema on physical examination at time of initial assessment.

9. Receiving optimal doses of ≥ 3 anti-hypertensive medications including furosemide at
≤80mg/d.9.

10. 8-10 in morning sitting Plasma aldosterone Concentration < 15ng/dL and Plasma Renin
Activity <0.6ng/mL/h

Exclusion Criteria:

1. Serum sodium<135meq/L based upon historical values

2. Serum potassium<3.5meq/L based upon historical values

3. Poorly controlled diabetes mellitus with HbA1c>9% based upon historical values

4. Already on thiazide

5. Arm circumference >42cm

6. Clinically significant hepatic dysfunction based upon medical history or historical
values

7. Two (2) Unsuccessful baseline ABPMs

8. Poor adherence in run-in period as suggested by an unsuccessful 24-h urine
collection.

9. DBP≥110 or SBP≥200

10. Allergy to Chlorthalidone