Sulfite Oxidase Deficiency and Molybdenum Cofactor Deficiency Medication

Updated: Feb 18, 2019
  • Author: Reena Jethva, MD; Chief Editor: Luis O Rohena, MD, PhD, FAAP, FACMG  more...
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Medication Summary

Cyclic pyranopterin monophosphate (cPMP) has shown promise in the treatment of molybdenum cofactor deficiency type A. The FDA has granted breakthrough therapy designation to cPMP replacement.

Various other drug treatments have been attempted. Doses are experimental and are not listed in this article. Attempt drug therapy with the assistance of a metabolic specialist or a neurologist. No drug treatments have proven effective in reversing profound brain damage in individuals with sulfite oxidase deficiency.

Betaine has been used to increase remethylation of homocysteine back to methionine, thus decreasing cysteine and, ultimately, sulfite levels (see the image below).

Sulfite oxidase deficiency and molybdenum cofactor Sulfite oxidase deficiency and molybdenum cofactor deficiency in the metabolism of sulfated amino acids.

High-dose thiamine has been used to replace thiamine destroyed by sulfite.

Cysteamine and penicillamine have been used to chelate sulfite. Cysteamine has been shown to have some biochemical effect; however, no clinical effect has been observed with use of this drug.

Supplementation with sulfate, molybdenum cofactor, tetrahydrobiopterin, and uric acid has been proposed in order to replace body stores. Molybdenum cofactor is not sufficiently stable for administration, and tetrahydrobiopterin supplementation has not been effective. Currently, no reports of effectiveness of sulfate and uric acid administration are available.


Enzymes, Metabolic

Fosdenpoterin (Nulibry)

Fosdenopterin is a substrate replacement therapy that provides an exogenous source of cPMP. This source converts to molybdopterin and eventually to molybdenum cofactor, which is necessary for the activation of molybdenum-dependent enzymes, including sulfite oxidase. It is the first FDA-approved therapy indicated to reduce the risk of mortality in patients with MoCD Type A.