Post chemo hiccups advice please

Hubby has started radiotherapy this week, had first round of chemo , Cisplatin plus iv Dexamerhasone and Ondansatron, on Tuesday. Sent home with oral Dex and Ondansatron 

Has been very burpy since yesterday am with almost constant hiccups. He’s got a couple of tricks which work at stopping the hiccups but they return within half hour. 

Does anyone have any advice please? Xx