Indications
Levomenthol (the natural form of menthol) is mainly found in cough and cold syrups, together with ingredients such as Diphenhydramine, Guaifenesin or Dextromethorphan. It helps relieve cough, throat irritation and the feeling of a blocked nose. It is also used in some inhalation products for nasal and chest congestion.
How It Works
Levomenthol acts on the cold-sensing nerve endings in the nose, mouth and throat. This gives a cooling, soothing feeling, makes breathing through the nose feel easier and calms the urge to cough. It eases symptoms but does not treat the cause of the cold or cough.
Dosage and Administration
- The dose depends on the combination product. Follow the label or the doctor’s advice; for many adult cough syrups this is 5 to 10 ml three or four times a day.
- Children: use only products and doses meant for children, as advised by a doctor. Do not use in children under 2 years.
- Do not use for more than 7 days without medical advice.
Interactions
Levomenthol itself has few interactions. The other ingredients matter more: Diphenhydramine adds to drowsiness with alcohol, sleeping tablets and other sedatives; Dextromethorphan must not be used with MAO inhibitors (such as Selegiline) and may interact with Fluoxetine and similar antidepressants. Do not take two cough and cold products together.
Contraindications
- Allergy to menthol or peppermint.
- Babies and young children under 2 years; menthol near the face of an infant can cause breathing problems.
- Any condition in which the other ingredients of the product are not allowed.
Side Effects
Usually mild: stomach upset, heartburn or nausea. Combination syrups may also cause drowsiness, dizziness or dry mouth.
Get urgent medical help for: trouble breathing (especially in a young child), signs of an allergic reaction such as rash, swelling of the face or lips, or extreme drowsiness or confusion.
Pregnancy and Lactation
The amount of levomenthol in these products is small, but the other ingredients may not be suitable. Ask a doctor or pharmacist before use in pregnancy or while breastfeeding.
Precautions and Warnings
- Combination syrups can cause drowsiness; do not drive if affected.
- Use with care in asthma, as strong menthol may rarely trigger wheezing.
- Syrups may contain sugar; people with diabetes should check the label.
- See a doctor if cough lasts more than a week, or comes with high fever, chest pain or blood.
Overdose
Swallowing a large amount can cause nausea, vomiting, stomach pain, dizziness, drowsiness, confusion and, rarely, fits. Overdose of the other ingredients can also be serious. Seek medical help straight away.
Therapeutic Class
Cooling agent and counter-irritant; ingredient of cough and cold preparations.
Storage
Store below 30°C in a dry place, away from light, with the cap tightly closed, out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.