CAPTOPRIL RENAL SCAN

This is very simple. You just do nuclear renograms, the first one as per usual, and the second one after you've given Captopril.
If there's a difference in the before and after clearance curves then there's a RAS.

There's a number of medications that need to be stopped before the captopril study:
5 days before - all ACEI and ARB's and all CCB's apart from nifedipine & verapamil
2 days before - nifedipine, verapamil