 [ Symptoms ] i can take an antihistamine or any medicine while using flonase amoxicillin and sudafed [ Disease ] hi this may be due to slipped disc in the lumbar spine this may be compressing the nerve that causes radiating pain in the legs you should get a mri of lumbar spine done to confirm the diagnosis use lumbosacral belt take anti inflammatory tablets hot fomentation local gel consult a orthopedist thanks