Brief Answer: Explained below. Detailed Answer: Hi, Welcome to Healthcare Magic! Red Bull energy drink contains high amounts of caffeine, taurine, sugar and other substances. There have been some studies on its effects, but there is no scientific data on its interaction with buprenorphine (Subutex). Whatever information is available is what people who have tried the combination themselves have written, and I agree with you that most people say that combining the two is not a good idea. But there are also some people who did not perceive any harmful effects on combining the two. Please try to look back and see if you made any changes to your usual pattern of taking the two things yesterday. Also take into consideration the number of cups of coffee you take in addition to Red Bull. If there was any change, that may explain what happened to you. If nothing is clear, try assessing if you might be in withdrawal from either Red Bull or Subutex. If you are having a craving for one of these, that may be a pointer. Both substances can make you feel low and fatigued during withdrawal. For Red Bull, there is not enough scientific data on dependence and withdrawal but caffeine withdrawal is known to cause depression and anxiety in susceptible people. The weather may have a role too. Perhaps it has made you take more coffee than usual for the last few weeks. It may also alter the body's metabolism to some extent. I hope this helps you to some extent. Please write back and let me know what you feel. Best wishes. Dr Preeti Parakh MD Psychiatry

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