Actonel drug use, side effects, for osteoporosis and bone thinning September 24 2017 by Ray Sahelian, M.D. Actonel is a prescription medication used for the treatment of postmenopausal osteoporosis. Actonel side effects, danger. Side effects for risedronate sodium tablets may include back, muscle, bone or joint pain, stomach pain or upset, or constipation. Sometimes a doctor who prescribes it does not tell their patient all the potential bad side effects. A very serious long term Actonel side effect is osteonecrosis of the jaw.