Indications
Glycyrrhiza glabra is liquorice root, one of the most widely used herbs in Unani, Ayurvedic and traditional medicine. It is found in many cough syrups, lozenges, digestive powders and herbal compounds. Traditionally it is used to soothe cough and sore throat, loosen phlegm, relieve hoarseness, calm acidity and stomach discomfort, and as a mild laxative and flavouring. Scientific evidence supports a soothing effect on the throat and some benefit for indigestion, but evidence for many other traditional uses is limited.
How It Works
Liquorice contains glycyrrhizin and flavonoids. It coats and soothes irritated surfaces of the throat and stomach, helps thin mucus so it is easier to cough up, and has mild anti-inflammatory effects. Glycyrrhizin can also act like the body hormone aldosterone, which makes the body hold on to salt and water and lose potassium. This is the main reason long-term or high-dose use can be harmful.
Dosage and Administration
Use as directed on the label of the specific product or by a registered practitioner. Herbal liquorice products are meant for short-term use, usually not longer than 4 to 6 weeks, unless a doctor advises otherwise. Do not exceed the recommended dose.
Interactions
- Water tablets (diuretics) such as Furosemide or Hydrochlorothiazide, and laxatives: higher risk of low potassium.
- Digoxin and medicines for heart rhythm: low potassium can increase the risk of dangerous heart rhythm problems.
- Blood pressure medicines: liquorice can raise blood pressure and reduce their effect.
- Corticosteroids such as Prednisolone: effects may be increased.
- Warfarin and other blood thinners: effect may be changed.
Contraindications
- High blood pressure that is not well controlled.
- Heart failure, heart rhythm problems, or kidney or liver disease.
- Low blood potassium.
- Pregnancy.
- Allergy to liquorice.
Side Effects
Small amounts for a short time are usually well tolerated. Regular or large amounts can cause raised blood pressure, swelling of the legs and face from fluid retention, headache, tiredness, and low potassium with muscle weakness or cramps. Stomach upset can also occur.
Get urgent medical help if you have severe muscle weakness, a fast or irregular heartbeat, chest pain, sudden severe headache, shortness of breath or marked swelling.
Pregnancy and Lactation
Avoid medicinal liquorice products during pregnancy, as high intake has been linked to preterm birth and other problems. During breastfeeding, avoid regular use unless a doctor advises it.
Precautions and Warnings
- Check blood pressure if using it for more than a couple of weeks.
- Elderly people and those with heart or kidney problems are more sensitive to its effects.
- Use in children only as directed on a product made for children.
- Remember that many herbal cough and digestive products contain liquorice: avoid taking several at once.
Overdose
Large amounts can cause high blood pressure, fluid retention, very low potassium, muscle weakness, paralysis and irregular heartbeat. Stop the product and seek medical help immediately if overdose is suspected.
Therapeutic Class
Herbal medicine (Unani and Ayurvedic): demulcent, expectorant and digestive herb.
Storage
Store below 30°C in a dry place, away from light and 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.