A pharmaceutical dosage system comprising (a) an effective amount of one or more of Doxylamine, an analog thereof, a derivative thereof, a prodrug thereof, a metabolite thereof and/or a salt thereof; (b) an effective amount of one or more of (i) Pyridoxine, (ii) an analog thereof, (iii) a derivative thereof, (iv) a prodrug thereof, (v) a metabolite thereof and (vi) a salt of any of (i)-(v); and (c) an effective amount of one or more compounds of formula (I)wherein R is H, PO3− orThe system exhibits an improved pharmacokinetic profile relative to the current Diclectin®/Diclegis® formulation and is useful for example for the alleviation of the symptoms of nausea and vomiting, for example in the case of nausea and vomiting of pregnancy (NVP).