Chapter 2: Table of Contents
Phenol and its derivatives are used as antiseptics, general disinfectants and in cold sterilants. Bisphenols and halogen-substituted phenols are phenol derivatives that are used as antiseptics.
Hexachlorophene is a bacteriostatic bisphenol that only possesses bacteriostatic activity against gram-positive bacteria. Hexachlorophene kills at a slow to intermediate rate but has a residual effect lasting several hours. It is inactivated if contacted with alcohol or other soaps but is not inactivated by organic debris. It can cause photosensitivity and dermatitis to people sensitive to phenols and should not be used on broken skin or mucous membranes due to irritation and absorption into the blood. Many skin preparations are more effective than hexachlorophene, reducing its use in veterinary medicine.
Parachlorometaxylenol (PCMX) is a halogen-substituted phenol that kills gram-positive bacteria by cell wall disruption and enzyme inactivation but has reduced activity against gram-negative bacteria. Like other antiseptics, it has poor activity against spores but does have virucidal activity against enveloped viruses. PCMX is often combined with other agents to potentiate its activity against gram-negative bacteria. Onset of action is slow to intermediate and contact times of a few minutes are recommended. PCMX may be toxic to cats since it requires hepatic glucuronate conjugation for excretion.