sinusitis
"Took Amox/KClav for sinusitis. After 3 days caused severe back pain radiating through right side. Pain became so bad that I stopped med after 3.5 days. Was told by nurse and pharmacist likely due to kidneys' being adversely affected. Called dr who ordered lowered dose who believes GI affected. Pain still so bad and refuse to take any meds until pain subsides as symptoms of med is far worse than sinusitis."