peppermint oil: clinical use

Prescribing considerations

• Confirm symptoms are consistent with IBS and assess new, changed or unexplained symptoms.
• Review reflux or hiatus hernia because peppermint oil may worsen heartburn.
• Check the selected brand's age, weight, pregnancy, breastfeeding and excipient restrictions.

Contraindications and cautions

• Hypersensitivity to peppermint oil, menthol or formulation excipients.
• Buscomint: liver disease, cholangitis, achlorhydria, gallstones or other biliary disorders.
• Buscomint: children younger than 12 years and people weighing under 40 kg.
• Colpermin: peanut allergy; people with soya allergy should also avoid it because it contains arachis oil.

Monitoring

• Monitor symptom response and reassess persistent, deteriorating or changed symptoms.
• Monitor for worsening reflux, gastrointestinal intolerance and hypersensitivity.
• During breastfeeding, where use is clinically appropriate, monitor the infant for feeding, weight gain, gastrointestinal disturbance, irritability and rash.

Clinical pharmacology

Gastro-resistant delivery delays release until the distal small bowel. Peppermint oil acts mainly locally, relaxing gastrointestinal smooth muscle; interference with calcium-ion mobilisation contributes to its antispasmodic effect.

Formulation and product differences

• Colpermin is a sustained-release, enteric-coated gastro-resistant capsule containing arachis oil and should be avoided in peanut or soya allergy; its product information reports no experience in children under 15.
• Buscomint is a gastro-resistant soft capsule without arachis oil listed; it has explicit restrictions for biliary disease, age and body weight.
• Pregnancy and breastfeeding wording differs between products, so decisions must use the leaflet for the exact brand.