Llanol Warnings

Allopurinol Hypersensitivity Syndrome: Allopurinol should be withdrawn immediately at the first sign of a skin rash or if other evidence of allergic reaction or hypersensitivity occurs. It should be withdrawn immediately and permanently at the first sign of intolerance.
Allopurinol may cause a rare but potentially life-threatening allopurinol hypersensitivity syndrome (AHS) which consists of an erythematous maculopapular rash with desquamation, fever, nephritis, eosinophilia, and worsening or renal function.
Severe hypersensitivity reactions (e.g., exfoliative, urticarial and purpuric lesions) as well as severe cutaneous adverse reactions [e.g., Stevens-Johnson Syndrome (SJS) or erythema multiforme exudativum, Toxic Epidermal Necrolysis (TEN) or Lyell's Syndrome, and/or generalized vasculitis], which may be fatal (deaths associated with allopurinol have been rare and almost always as a result of generalized hypersensitivity), have been reported following the appearance of skin rash. Very rarely, acute anaphylactic shock has been reported. If such reactions occur, which may be at any time during treatment, allopurinol should be withdrawn immediately and permanently. When generalized hypersensitivity reactions occur and a renal and/or hepatic disorder is present, the outcome could be fatal