Adverse Reactions: Nausea, headache, GI distress, vomiting, syncope, hypotension, and other signs of hypersensitivity, cardiac arrest, basilar artery ischemia, severe shock, convulsions, death (rare), hives, itching, bronchospasm, anaphylaxis, pyrexia, transient dyspnea, angioneurotic edema, and slight dizziness. Some of these may be related to the site of injection, but the potential for these kind of side effects does not sound nontoxic to me.