Nitrous Oxide/ Oxygen

Registered South African indications:

• Analgesia

Contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Abdominal distensions
• Pneumothorax
• Pneumopericardium
• Bullae in the lungs 
• Middle ear surgery

Cautions

• Increased intracranial pressure
• Head injuries
• Space occupying intracranial lesions
• Pulmonary hypertension
• Major bowel surgery or any type of ileus
• Vitamin B12 deficiency
• Dihydropteridine reductase deficiency
• Other nutritional deficiencies
• Bleomycin chemotherapy

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

Analgesia

• Inhaled (gas): Nitrous oxide 50% mixture with oxygen

See adult dosage

Pregnancy

• FDA Pregnancy Category Not Rated (NR)

Breastfeeding

• Compatible

Renal Impairment

• No dose adjustment recommended

Hepatic Impairment

• No dose adjustment recommended 

Elderly

• No dose adjustment recommended

Porphyria Information

• Not yet classified (NC)

Central Nervous System Disorders

• Myeloneuropathies
• Neuropathies 
• Psychosis 

Cardiovascular Disorders

• Arrhythmias
• Hypotension

Immune, Blood and Lymphatic System Disorders

• Folate deficiency
• Myelosuppression 

Sensory Disorders

• Increase in middle ear pressure

Others

• Malignant hyperthermia

• Central nervous system depressants
• St John’s wort

None routine

Nitrous oxide induces opioid peptide release in the brain stem, resulting in activation of opioid receptors and descending GABA and noradrenergic pathways that modulate nociceptive processing at the spinal level. 

COMBINATION PREPARATIONS

Nitrous Oxide/ Oxygen

• Entonox (Afrox)