Though Klonopin can help decrease anxiety, it has its downsides as well. If you’ve been prescribed Klonopin, know that you may experience some side effects, such as fatigue, dizziness, confusion, difficulty remembering certain things, muscle aches, and lack of libido. Other symptoms are more severe, but less common, including inflammation of the face and throat, hives, and breathing difficulties. Not everyone experiences these side effects, however.