Hypersensitivity: Bisphosphonates may rarely cause hypersensitivity reactions such as angioedema, urticaria, and pruritus. A possibly drug-related rash has also been reported in a patient receiving alendronate. Other cutaneous reactions reported with alendronate include urticaria, erythematous papules and petechiae, gyrate erythema, and drug-induced lichen planus; licensed product information states that Stevens-Johnson syndrome has been reported.