Phenazone/ Benzocaine/ Chlorbutol

Registered South African indications:

• Acute otitis media, simple catarrhal otitis, furunculosis and other inflammatory conditions and infections of the ear

Combination products may have additional pharmacological effects not accounted for by the action of the individual ingredients

Contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Administration of phenazone is contraindicated where there is a family history of porphyria

Cautions

Caution in the following patient groups

• Pregnancy
• Breastfeeding
• Elderly
• Epilepsy
• Impaired cardiac conduction
• Shock
• Myasthenia gravis
• Liver damage

Prolonged use

• Avoid applying local anaesthetics to the skin for prolonged periods or over extensive area

Ability to drive and use machines

• Effects on driving and using machines are not known

Forms avail. in SA and covered in this monograph: dro

South African registered indications and dosages

Acute otitis media, simple catarrhal otitis, furunculosis and other inflammatory conditions and infections of the ear

Phenazone/ Benzocaine/ Chlorbutol
750/150/150 (mg/15ml)

• Otic (dro): 5-10 drops (warmed to body temperature), 2hrly and the ear lightly plugged with cotton wool

No information available

Recommendations for this combination product as per highest risk category when comparing individual active ingredients

Pregnancy

• FDA Pregnancy Category C (Phenazone, Benzocaine)

Breastfeeding

• Caution; not recommended (Phenazone)

Renal Impairment

• No dose adjustment recommended (Phenazone, Benzocaine)

Hepatic Impairment

• No dose adjustment recommended (Phenazone, Benzocaine)

Elderly

• Caution; no dose adjustment recommended (Benzocaine)

Porphyria

South African recommendations

• Family history of porphyria: Contraindicated

Combination products may have additional pharmacological effects not accounted for by the action of the individual ingredients

Phenazone
Skin and Subcutaneous Tissue Disorders

• Skin eruptions

Immune disorders

• Hypersensitivity reactions

Benzocaine
Central Nervous System Disorders

• Headache
• Lethargy
• Seizures
• Coma

Cardiovascular Disorders

• Hypotension
• Arrhythmia 
• Myocardial infarction 

Respiratory Disorders

• Apnoea
• Hyperventilation
• Hypoxia 

Gastrointestinal Disorders

• Nausea and vomiting
• Dysgeusia 

Skin and Subcutaneous Tissue Disorders

• Contact dermatitis
• Atopic dermatitis 
• Diaphoresis
• Photosensitivity

Immune, Blood and Lymphatic System Disorders

• Methaemoglobinaemia
• Hypersensitivity

Combination products may have additional pharmacological effects not accounted for by the action of the individual ingredients

Phenazone

• No information available

Benzocaine

• Hyaluronidase
• St John's wort 
• Sulphonamides

None routine

Phenazone
Thought to act primarily in the central nervous system, increasing the pain threshold by inhibiting cyclooxygenase, involved in prostaglandin synthesis.

Benzocaine
Benzocaine binds to sodium channels and reversibly stabilizes the neuronal membrane which decreases the permeability to sodium ions. Depolarization of the neuronal membrane is inhibited thereby blocking the conduction of nerve impulses. 

Chlorbutol
This ingredient has no pharmacological effect.

COMBINATION PREPARATIONS

Phenazone/ Benzocaine/ Chlorbutol
Drops (per 15ml) 750mg/ 150mg/ 150mg

• Aurasept (Adcock)
• Aurone Forte (Pharmacare)