Hi ! My Kris had relentless hiccups which stopped him breathing at times. They lasted for 10 days post Cisplatin and nothing stopped them. We tried Chlorpromazine plus Haloperidol, plus Lorazepam plus . I ended up giving Kris a tablet of some kind every 2 - 3 hours... It made the hiccups more manageable , but did not relieve them.
Best of luck.
Tammy

Caregiver/advocate to Husband Kris age 59@ diagnosis
DX Dec '10 SCC BOT T4aN2bM0 HPV+ve.Cisplatin x3 35 IMRT.
PET 6/11 clear.
R) level 2-4 neck dissection 8/1/11 to remove residual node - necrotic with NED
Feb '12 Ca back.. 3/8/12 total glossectomy/laryngectomy/bilat neck dissection/partial pharyngectomy etc. clear margins. All nodes negative for disease. PEG in.
March 2017 - 5 years disease free. Woohoo!