Amylmetacresol (AMC) is an antiseptic used to treat infections of the mouth and throat. It is used as an active pharmaceutical ingredient in Strepsils, Cēpacol, Gorpils, Cofsils and Lorsept throat lozenges, typically in combination with dichlorobenzyl alcohol, another antiseptic.

Medical uses

The lozenges are used to treat sore throat and minor mouth and throat infections including pharyngitis and gingivitis. A 2017 meta-analysis found that the combination of AMC with dichlorobenzyl alcohol has a modest advantage over un-medicated lozenges regarding pain relief.

Contraindications

No contraindications are known apart from hypersensitivity to the substance.

Adverse effects

Amylmetacresol sometimes causes soreness of the tongue. Hypersensitivity reactions are very rare and show symptoms such as nausea or dyspepsia, although it is not entirely clear which side effects are caused by AMC and which by dichlorobenzyl alcohol or other ingredients of the lozenges. AMC has a low toxicity with an LD50 of 1500 mg/kg body weight (in rats).

Overdose

No cases of overdosing have been reported. It is not expected to cause symptoms other than gastrointestinal discomfort.

Interactions

No interactions with other drugs are known.

Pharmacology

Mechanism of action

Amylmetacresol is an antibacterial and antiviral substance. It also blocks sodium channels in a manner similar to local anaesthetics. It has a Rideal-Walker coefficient of 250.

Pharmacokinetics

The substance is rapidly absorbed. It is oxidised to a carboxylic acid, glucuronidated, and quickly eliminated via the kidneys.

Chemistry

AMC is a derivative of m-cresol, with a pentyl group attached to the sixth carbon atom. The pure substance melts at 24 °C, and boils between 137 and 139 °C at a pressure of 6.7 kPa. It is soluble in water, ethanol, acetone, diethylether, and oil.