ZOLACAP powder for injection is commonly well tolerated. The following adverse reactions have been reported in patients who are receiving Omeprazole therapy in clinically controlled situations: Headache, diarrhea, abdominal pain, nausea, vomiting, upper respiratory tract infection, vertigo, rash, constipation, cough, asthenia, low back pain. Most adverse reactions are mild and temporary and do not have any consistent relationship with the treatment.