My Father 83 Years Old Went To Hospital 2 Weeks

My father 83 years old went to hospital 2 weeks ago with pain in his chest. Immediately they gave him a sublingual dose of nitro and also put a patch on his arm as well. He began to feel much worse and vomited many times... His stay in emerg was 8 hours and he vomited right up until they finally took the patch off.
He has not been feeling well since then.
Can this be a side effect of nitroglycerin ? He was cleared to go home.