What should I do if my husband has been sweating and vomiting after injecting 30 units of lantis insulin?

Proximity to admin. Since lantus (insulin glargine) is a long acting insulin analog with onset of action starting about 1 hr after administration, it is possible to have an effect, but this would be unusual since one of its benefits is the lack of a peak. Therefore, it is advisable to carefully monitor his glucose level before and each hour after and discuss with your PCP. There are reports of low glucose levels and must be ruled out.
Sugar and fluids. Your husband has possibly hypoglycemia, you want to check his blood glucose and if is low, give him to drink fruit juice.If he holds it ,continue to monitor his sugar very frequent for the next 12 hours. If he can not hold fluids, call 911, he needs to be treated with IV fluids and sugar and monitored .