Red man syndrome is due to:
Vancomycin has the potential to release histamine by direct action on mast cells. Rapid i.v. injection has caused chills, fever, urticaria and intense flushing-called ' Red man syndrome'.
Reference: Essentials of Medical Pharmacology Eighth Edition KD TRIPATHI page no 806
Vancomycin
Polymyxin
Rifampicin
Teicoplanin