Primary Distal Renal Tubular Acidosis

The treatment for primary distal renal tubular acidosis (primary dRTA) focuses on managing the pH levels of the blood using medicines to make the blood less acidic and a keep it more neutral by keeping the pH between 7.35 to 7.45. This is called alkali therapy and usually involves giving sodium bicarbonate or sodium citrate several times a day. To understand alkali therapy it helps to understand pH and the body a little better.

Organs in the body, such as the lungs and kidneys, work as a team to keep the acid-base balance in their blood stable over the course of the day. The balance is affected by many factors inside and outside the body ranging from how fast we breath out carbon dioxide to how well the kidneys are working. The acid-base balance is the medical term for how acidic (low pH) or alkaline (high pH) the blood is at point in time as measured on the pH scale. The pH scale, ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0, in the middle of this scale, is neutral. Blood is normally slightly basic, with a normal pH range of 7.35 to 7.45.

A doctor measures a person's acid-base balance by measuring the pH and levels of carbon dioxide (an acid) and bicarbonate (a base) in the blood. In primary dRTA, the blood is usually acidic and treatment to improve the acid-base balance is alkali therapy using sodium bicarbonate or sodium citrate.

Dosage and timing of doses depends on the age and weight of the person living with primary dRTA. Children require higher and more frequent doses (around 4-8 meq/kg/day) than adults. Adults require lower doses at around 1-2 meq/kg/day. Potassium replacement with potassium citrate is necessary for some patients with low potassium levels (hypokalemia). That dose depends on the severity of hypokalemia.

About 17-30% of treated patients have progressive chronic kidney disease particularly if there are recurrent kidney stones or severe calcium deposits in the kidneys. Kidney failure does happen and is treated with dialysis and kidney transplant, but when the patient is treated with alkali therapy this problem is rare.

Unlike kidney disease, alkali treatments do not appear to help stop or decrease hearing loss in primary dRTA. Accordingly, it is important to have regular hearing (audiologic) assessments to monitor hearing in people living with primary dRTA. Frequent testing can identify hearing loss early and move them quick to hearing support options as hearing aids and cochlear implants that have both been found to be successful in the management of hearing loss in children with primary dRTA.

With treatment, there is no decrease in life expectancy for patient diagnosed with primary dRTA; however, there can still be health issues such as hearing loss or kidney problems that requires close monitoring by an experience doctor.

As of 2018, there is not a cure for primary distal renal tubular acidosis (primary dRTA); however an extended release form of alkali therapy (Advicenne's ADV7103) is in clinical trials to examine its safety and effectiveness in maximizing alkali therapy over a 12-hour period and decreasing treatment to twice a day.