The most common adverse reactions of Soma include drowsiness, irritability, upset stomach, tremor, agitation, dizziness, nausea, insomnia, nervousness, etc. If Soma has taken for a prolonged time period, it might cause severe side effects such as drug dependence, abuse, and seizure. Some adverse reactions of Soma 350mg may happen and that do not require medical treatment. These adverse effects may cure along with your medication treatment since your body responses to the medication.