I have had diabetes for the past few years. I was taking Janumet 50 milligrams/500 milligrams and Vobit 0.3 milligrams to control diabetes, and Olmy 20 milligrams to control high blood pressure. However, my doctor has changed the medicine to Glycomet 500 SR. Is it normal, and can I take Glycomet with Vobit 0.3 milligrams? Also, my performance has degraded. I am not able to perform well at my workplace. Why so?