Glycerin

Indications

Glycerol (also called glycerin) is used as a suppository to relieve occasional constipation and to empty the bowel. It is also used on the skin as a moisturiser for dry or cracked skin, and as a soothing ingredient in some cough syrups and throat products. Doctors sometimes use special glycerol preparations for other purposes, which are given as prescribed.

How It Works

In the rectum, glycerol draws water into the bowel and mildly irritates the lining, which softens the stool and triggers a bowel movement, usually within 15 to 30 minutes. On the skin it attracts and holds moisture.

Dosage and Administration

• Suppository, adults and children over 12 years: one 4 g suppository when needed. Children: smaller suppositories (2 g for children, 1 g for infants), only as advised by a doctor.
• Moisten the suppository with a little water, insert it gently into the back passage, and stay lying down for a few minutes. Do not swallow suppositories.
• Skin: apply a thin layer to dry areas as needed.

Interactions

No important interactions are known with suppositories or skin use.

Contraindications

Suppositories should not be used if there is a blocked bowel, unexplained stomach pain, nausea or vomiting, or bleeding from the back passage, or by people allergic to glycerol.

Side Effects

Suppositories may cause mild discomfort, burning or irritation in the back passage and stomach cramps.

Get urgent medical help for severe or persistent stomach pain, bleeding from the back passage, no bowel movement with a swollen tummy and vomiting, or signs of a severe allergic reaction.

Pregnancy and Lactation

Glycerol suppositories are generally considered suitable for occasional use in pregnancy and breastfeeding. Speak to a doctor or midwife if constipation continues.

Precautions and Warnings

• For occasional use only; regular use for a long time should be under medical advice.
• See a doctor if constipation lasts more than a week, keeps coming back, or comes with weight loss, blood in the stool or a change in bowel habit.
• Drink enough fluids and eat fibre-rich food to help prevent constipation.

Overdose

Using too many suppositories may cause diarrhoea and cramps. If glycerol is swallowed in large amounts, it may cause headache, nausea, vomiting, thirst and diarrhoea; seek medical advice.

Therapeutic Class

Osmotic and stimulant laxative (rectal); emollient for the skin.

Storage

Store below 30°C in a cool, dry place, away from light and out of the reach of children. Suppositories may soften in heat; if so, cool them in the fridge briefly before use.