Types of RTA: Type 4: Hyperkalemic RTA

This form of RTA is most often referred to as type 4. It occurs when blood levels of the hormone aldosterone are low or when the kidneys do not respond to it. Aldosterone directs the kidneys to regulate the levels of sodium, potassium, and chloride in the blood. Type 4 RTA is distinguished by a high blood-potassium level.

Hyperkalemic distal RTA may result from sickle cell disease, urinary tract obstruction, lupus, amyloidosis, or transplantation.

Aldosterone's action may be impeded by drugs, including

• diuretics used to treat congestive heart failure such as spironolactone or eplerenone
  
  
• blood pressure drugs called angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs)
  
  
• the antibiotic trimethoprim
  
  
• an agent called heparin that keeps blood from clotting
  
  
• the antibiotic pentamidine, which is used used to treat pneumonia
  
  
• a class of painkillers called nonsteroidal anti-inflammatory drugs (NSAIDs)
  
  
• some immunosuppressive drugs used to prevent transplant rejection
  
  

For people who produce aldosterone but cannot use it, researchers have now identified the genetic basis for their body's resistance to the hormone. To treat type 4 RTA successfully, patients may require alkaline agents to correct acidosis as well as medication to lower the potassium in their blood.

If treated early, most people with RTA will not develop permanent kidney failure. Therefore, the goal is early recognition and adequate therapy, which will need to be maintained and monitored throughout the patient's lifetime.

source: http://kidney.niddk.nih.gov/kudiseases/pubs/tubularacidosis/index.htm