Proposition of zinc supplementation during levodopa–carbidopa intestinal gel treatment

OBJECTIVES: Levodopa–carbidopa intestinal gel (LCIG) infusion is a useful therapy for the wearing‐off phenomenon of advanced Parkinson's disease (PD) patients. Recently, we found three PD patients that may have had a zinc deficiency after the LCIG infusion, possibly due to the zinc‐chelating action of levodopa. This study aims to evaluate changes in serum zinc levels in three patients that received LCIG treatment and to determine possible remedies for zinc deficiency during treatment. MATERIALS AND METHODS: We performed a prospective blood analysis of serum zinc levels before, when possible, and after LCIG treatment in our three PD patients. RESULTS: The serum zinc levels of the first patient before treatment and 4 months after beginning LCIG treatment were 69 and 58 μg/dl, respectively. For the second patient, serum zinc levels before treatment and two months after starting LCIG treatment were 87 and 46 μg/dl, respectively. The baseline serum zinc level for the third patient was not examined, but was 48 μg/dl 5 months after starting the LCIG infusion. CONCLUSIONS: Levodopa–carbidopa intestinal gel infusion might have caused a zinc deficiency through levodopa zinc chelation. Zinc deficiency with LCIG infusion has not yet been reported, though preventing zinc deficiency may be an important factor in future LCIG treatment strategies.