What Causes Nausea And Blurred Vision While On Metoprolol And Venlafaxine?

Hi Dr Rynne, I am typing this for my Mom who is 88. She has been hospitalized 2 times for 8 and 7 days since 2/15. She has stage 4 COPD. She was hospitalized on 2/14 for Influenza A, tachacardia 130 bpm and A-fib. she also had a UTI and her white blood count was 18. They shocked her heart back into rhythm. She was released on 2/22. On 2/23 she developed another UTI. SHE went back to the ER on 3/5 with blood pressure of 88/44 and her heart was back in A-Fib with a flutter. She also had celulitis. She was released on 3/10. They put her on amiodarone (200mg oral tablet) Metoprolol tartrate 25mg and took her off cold turkey from Venlafaxine(150mg) which she had been on for 6 yrs. She started getting Nauseous 3/14 with blurred vision, swelling in feet and ankles, numbness and tingling in hands and feet. Blood pressure dropping heart rate over 100. I called the cardiologist and they said to discontinue the amiodarone which we did 3/15. She is not getting any better. I am concerned she is dehydrated or sepsis. She does not want to go back to the ER. My question is if she is dehydrated, can she drink water to re hydrate or does she need an IV?