Abdominal pain, asthenia, constipation, diarrhea, dyspepsia, flatulence, nausea, headache, dizziness. 20-mg tab: Upper resp tract infections, skin rashes, blurred vision, insomnia & dysgeusia. 40-mg tab: Pruritus, alopecia, muscle cramps, myalgia, pancreatitis, paraesthesia, peripheral neuropathy, vomiting & anemia.