Treatment of multiple carboxylase deficiency –
Pathogenesis of multiple carboxylase deficiency 

Deficiency of either holocarboxylase synthase or biotinidase impaires biotin metabolism.
Biotin is a cofactor for various carboxylases in the body -
Impaired metabolism of biotin results in multiple carboxylase deficiency.
So, for the treatment of multiple carboxylase deficiency, biotin should be given.
Biotin
Pyridoxine
Thiamine
Folic acid