Muscle in my back. Are there any side effects of zanaflex (tizanidine)?

Sedation. Sedation is the most common side efffect seen. Dry mouth is also an issue. Zanaflex (tizanidine) is a great drug for muscle spasm.
Yes. There are potential side effects from any medication. No med is side effect free. With zanaflex, (tizanidine) the most common side effects are drowsiness and low blood pressure. This does not mean they will always occur but they can occur. I always advise my patients to take the med at home, do not drive when first taking the medication just to see how it affects you.