Peppermint: Contraindications and Precautions. Pregnancy Use

2010

Significant Interactions

Controlled studies are not available; therefore, interactions are based on evidence of activity and are largely theoretical and speculative.

FELODIPINE

Peppermint oil has been shown to increase the oral bioavailability of felodipine in animal studies — use this combination with caution.

SIMVASTATIN

Peppermint oil has been shown to increase the oral bioavailability of simvastatin in animal studies. Observe the patient and monitor drug requirements — possible beneficial interaction.

CYCLOSPORIN

Peppermint oil has been shown to increase the oral bioavailability of cyclosporin in animal studies — avoid concurrent use, unless under medical supervision.

DRUGS METABOLISED BY CYP3A4 LIVER ENZYME

Peppermint may increase the oral bioavailability of certain drugs by inhibition of CYP3A4-mediated drug metabolism, which has been demonstrated in vitro but not in test animals. Although these studies seem to suggest that peppermint may modulate drug metabolising enzymes, the clinical significance of this is unknown and requires further investigation. Caution is advised.

Contraindications and Precautions

Hypersensitivity to peppermint oil.

Non-enteric-coated peppermint may be best avoided in patients with reflux oesophageal symptoms. Avoid chewing enteric-coated capsules as it may cause heartburn. Avoid the use of peppermint oil on the face of infants and small children. Capsules containing peppermint oil are contraindicated in biliary duct occlusion, gall bladder inflammation and severe liver damage.

Pregnancy Use

Safe dosages in pregnant women have not been determined; however, external use is likely to be safe.