Generic Lodosyn drug side effects may include dizziness, nausea, vomit, irregular heartbeat, fainting, easy bleeding/bruising, signs of infection (e.g., fever, persistent sore throat), tingling of the hands/feet, vision changes (e.g., blurred/double vision), chest pain, seizures, vomit that looks like coffee grounds, black/tarry stools, fast/shallow breathing, confusion, severe dizziness/fainting, high fever, muscle stiffness, unusual sweating and allergic reaction. Suddenly stopping or lowering the dose of this medication may seldom cause neuroleptic malignant syndrome.