Senna for constipation

This leaflet is about the use of Senna for constipation.

This leaflet has been written for parents and carers about how to use this medicine in children. Our information sometimes differs from that provided by the manufacturers, because their information is usually aimed at adult patients. Please read this leaflet carefully. Keep it somewhere safe so that you can read it again.

Name of drug

Senna
Brand names: Manevac®, Senokot®

Why is it important for my child to take this medicine?

When a child is constipated, their stools (poo) are hard and painful to pass. Sometimes a child may try to hold the stool in because of previous pain when going to the toilet . Constipation can also make the child feel quite poorly.

Your doctor will probably prescribe a type of medicine called an osmotic laxative (e.g. lactulose, polyethylene glycol [Laxido, Movicol]) to give to your child first. This will soften the stool (poo). Senna is then used to help your child to pass the softened stool.

It is important that your child takes senna regularly, as it may take some time for the constipation to get better.

• You can find more information about constipation in children and young people produced by NICE (National Institute for Health and Care Excellence).

What is senna available as?

• Tablets: 7.5 mg
• Granules: 400 g; these contain sugar
• Liquid medicine: 7.5 mg in 5 mL

When should I give senna?

Senna is usually given once each day. You can give it either before the evening meal (which should help your child to do a poo in the morning), or in the morning (before breakfast). 

Give the medicine at about the same time each day so that this becomes part of your child’s daily routine, which will help you to remember.

How much should I give?

Your doctor will work out the amount of senna (the dose) that is right for your child. The dose will be shown on the medicine label.

It is important that you follow your doctor’s instructions about how much to give.

How should I give senna?

Tablets should be swallowed whole with a glass of water, milk or juice. Your child should not chew the tablet.

Liquid medicine: Measure out the right amount using a medicine spoon or oral syringe. You can get these from your pharmacist. Do not use a kitchen teaspoon as it will not give the right amount.

Granules: Mix the granules into a cold or warm drink. Your child should swallow it all straight away. (The granules will swell when they come into contact with the liquid, so the mixture should be drunk straight away.) If you prefer, you can sprinkle the granules onto a small amount of food (such as yogurt, honey or jam). 

Your child should drink a full glass of water afterwards.

When should the medicine start working?

Your child should be able to do a poo 8–12 hours after taking a dose of senna. However, if the constipation is bad, it may be a few days before they do a poo. Continue to give the medicine each day. Your child should not strain to do a poo.

What if my child is sick (vomits)?

• If your child is sick less than 30 minutes after having a dose of senna, give them the same dose again.
• If your child is sick more than 30 minutes after having a dose of senna, you do not need to give them another dose. Wait until the next normal dose.

What if I forget to give it?

• If you normally give it in the morning: Give your child the missed dose when you remember during the day. This should be at least 12 hours before the next normal morning dose is due.

• If you normally give it in the evening: You do not need to wake your child up to give the missed dose. Give it in the morning before breakfast. This should be at least 12 hours before the next normal evening dose is due.

What if I give too much?

If you give too much senna, your child may get stomach ache or diarrhoea.

If you think you may have given your child too much senna, contact your doctor or local NHS services (111 in England and Scotland; 0845 4647 in Wales). Have the medicine packet with you if you telephone for advice.

Are there any possible side-effects?

We use medicines to make our children better, but sometimes they have other effects that we don’t want (side-effects).

• Your child may get stomach cramps. This usually wears off after a few doses. If it is still a problem when your child has been taking senna for a week, contact your doctor.
• If your child gets diarrhoea, contact your doctor, as they may want to reduce the dose of senna.
• If your child has bad or watery diarrhoea, or seems tired  and weak, contact your doctor.

There may, sometimes, be other side-effects that are not listed above. If you notice anything unusual and are concerned, contact your doctor. You can report any suspected side-effects to a UK safety scheme at http://www.mhra.gov.uk/yellowcard.

Can other medicines be given at the same time as senna?

• You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.
• Senna should not be taken with some medicines that you get on prescription. Tell your doctor and pharmacist about any other medicines your child is taking before giving senna.
• Check with your doctor or pharmacist before giving any other medicines to your child. This includes herbal or complementary medicines.

Is there anything else I need to know about senna?

Do not give senna without plenty of water. It will not work properly and you risk causing dehydration.

• Senna belongs to a group of drugs called stimulant laxatives. Before giving senna, it is important to soften your child’s stools. You can do this by increasing the amount of high-fibre foods such as fruit, vegetables, bran and high-fibre cereals that they eat, and encouraging them to drink plenty of water. Or you might have been prescribed an osmotic laxative – another type of laxative that works by softening the stools.
• Encouraging your child to be active will also help their constipation. Your pharmacist, doctor or health visitor will be able to give you advice and support.
• Your child may get stomach cramps. This usually wears off after a few doses. If it is still a problem when your child has been taking senna for a week, contact your doctor.
• If your child has diarrhoea, contact your doctor, as they may want to reduce the dose of senna.
• If your child has bad or watery diarrhoea, or seems tired and weak, contact your doctor.

General advice about medicines 

• Try to give medicines at about the same times each day, to help you remember.
• Only give this medicine to your child. Never give it to anyone else, even if their condition appears to be the same, as this could do harm. 
• If you think someone else may have taken the medicine by accident, contact your doctor for advice.
• Make sure that the medicine you have at home has not reached the ‘best before’ or ‘use by’ date on the packaging. Give old medicines to your pharmacist to dispose of.

Where should I keep this medicine? 

• Keep the medicine in a cupboard, away from heat and direct sunlight. It does not need to be kept in the fridge.
• Make sure that children cannot see or reach the medicine.
• Keep the medicine in the container it came in.

Who to contact for more information 

Your child’s doctor, pharmacist or nurse will be able to give you more information about senna and about other medicines used to treat constipation.