Is Magnesium Chloride Supplement Advisable For A Diabetic Patient?

My husband has just been released from hospital. While in hospital he was given magnesium chloride intravenously because his levels of magnesium were low. He is type II diabetic, he was dehydrated upon admittance, was running low grade fever, and was given saline intravenously for a couple of days to hydrate. He was diagnosed(finally) with having a bacterial infection but could not identify the source of the infection. He was in hospital about 4 days, tests were run and 2 types of antibiotics were administered. He s been released to come home. My question is: will the medication magnesium chloride be safe for him to take? (it was prescribed by the doctor of course) Looking at some of the side effects (swelling of tongue) really scares me and he may not take it if he thinks that it will cause him swelling, especially the tongue. He s had that happen to him once with the drug Lisinipril used for high blood pressure. What do you think?