What are some of the dangers of zanaflex (tizanidine)?

Allergic reactions: Zanaflex (tizanidine) commonly causes dry mouth and constipation, but in some people there are some dangerous potential effects, many of which are allergies (rash, hives, itching, and swollen airways causing breathing difficulties). Other dangers include potential liver damage and psychological effects such as hallucinations. If you have any side effect from any medication inform your doctor.