Generic Acyclovir side effects include but are not limited to nausea, back and side pain, extreme tiredness, and a possible life threatening disorder in patients with a weakened immune system. Serious allergic reactions are rare but could include swelling to the face, tongue, and throat. Cheap Acyclovir online is available and can be beneficial to many patients. Depending on the treatment that you buy Acyclovir from, the dose will change. There are short and long term administrations as well as dosing charts for shingles and chicken pox. Severe reactions include breathing difficulty, hallucinations, bruising of fever, blood in the urine, yellowing of the skin or eyes, vision changes, and hoarseness. Indications in changes of gastrointestinal function, renal failure or pain, and fatigue were also reported.