03/23/2014

#112 Now that Cytra-K Crystals are not available, how is acidosis treated?

The cause for acidosis is always very helpful in determining the solution. If the patient just started the diet acidosis can be strong but generally corrects itself on its own unless there are other contributing factors such as certain medications, insufficient calories or a metabolic problem. The CO2 level on a Electrolyte panel indicates acidosis if it is lower than normal.

Acidosis should be neutralized with a buffer. Cytra-K Crystals are the lowest carbohydrate citrate buffe available in the US but is currently on “back-order” according to the manufacturer. Another neutralizer is bicarbonate. Baking soda is a combination of bicarbonate and sodium. This salt is effective but should be dosed according to age weight: 0.5-4mEq/kg is the suggested dose for buffering.  This should be dissolved in water and spread out over 10-12 hours – never taken all at once. Water is itself a strong acid neutralizer and should be provided in sufficient amount – again this is based on weight. The water can be flavored with a sugar-free flavoring and/or extract. A typical dose of baking soda and water for a child is 1 teaspoon dissolved in 1 to 1.5 liter of water (4 c- 6 c) water in one day. There is a concern that baking soda can cause low phosphorus levels; for this reason, it is also recommended to supplement with posphorus which is also a buffer and can help to correct acidosis.

Patients receiving a carbonic anyhydrase inhibitor (i.e. topiramate or zonisamide are 2 antiseizure meds) will almost always become acidodic on the diet and are often acidodic beforehand. This is the warning on the package insert of zonisamide: “FDA recommends that healthcare professionals measure serum bicarbonate before starting treatment and periodically during treatment with zonisamide, even in the absence of symptoms and is working.” Typically the dose of zonisamde and  topiramate need to be reduced during ketogenic diet therapy to resolve acidosis.