Mixture of clopidogrel bisulfate and magnesium oxide tablets reduces clopidogrel dose administered through a feeding tube

BACKGROUND: In clinical practice, a mixed suspension of clopidogrel bisulfate and magnesium oxide (MgO) tablets is administered frequently via a feeding tube. However, there is no report on the changes occurring when suspensions of these two drugs are combined, including the effects or potential decrease in dose following tube administration. Thus, the purpose of our study was to investigate the (i) changes caused by mixing clopidogrel bisulfate (ion form) and MgO tablets and (ii) effects on the administered clopidogrel dose after passing through a feeding tube. METHODS: The molecular structure of clopidogrel generated in a mixture of clopidogrel bisulfate and a basic compound, such as sodium bicarbonate or MgO tablet, was determined by (1)H-NMR after extraction and purification. The suspension of clopidogrel bisulfate tablet alone and the mixed suspension of clopidogrel bisulfate tablet and MgO tablet were passed through a feeding tube. We compared the yield of the molecular form of clopidogrel from each passed fraction. RESULTS: The substance obtained from the mixture of clopidogrel bisulfate tablet and sodium bicarbonate or MgO tablet was identified as the molecular form of clopidogrel, and chemical degradation did not occur under these conditions. In the tube passage test, the yield of clopidogrel (molecular form) from the mixture of clopidogrel bisulfate and MgO tablets was lower than that from the suspension of clopidogrel bisulfate tablet alone. CONCLUSIONS: The mixture of clopidogrel bisulfate and MgO tablets caused a considerable reduction in the administered dose passed through the feeding tube. Therefore, it is recommended to administer the suspensions of clopidogrel bisulfate and MgO tablets separately for safe and effective pharmacotherapy.