Patient leaflet - Zantac tablets 150 mg
1 What Zantac is and what it is used for
Zantac contains a medicine called ranitidine. This belongs to a group of medicines called H2-receptor antagonists. It lowers the amount of acid in your stomach.
For adults (including the elderly) Zantac is used to:
- heal and stop ulcers in the stomach, or the part of the gut it empties into (the duodenum)
help clear up infection in your stomach, when taken with antibiotic medicines
(medicines taken to treat germs)
- stop stomach ulcers when they are a side effect of some medicines
- stop ulcers from bleeding
- improve problems caused by acid in the food pipe (oesophagus) or too much acid in the stomach. Both of these can cause pain or discomfort sometimes known as ‘indigestion’, ‘dyspepsia’ or ‘heartburn’
- stop acid coming up from the stomach while under anaesthetic during an operation.
For children (3 to 18 years) Zantac is used to:
- heal ulcers in the stomach, or the part of the gut it empties into (the duodenum)
- heal and stop problems caused by acid in the food pipe (oesophagus) or too much acid in the stomach. Both of these can cause pain or discomfort sometimes known as ’indigestion’, ’dyspepsia’ or ’heartburn’.
2 What you need to know before you take Zantac
Do not take Zantac if:
- you are allergic to ranitidine or any of the other ingredients of this medicine (listed in section 6).
If you are not sure, talk to your doctor or pharmacist before taking Zantac.
Warnings and precautions
Check with your doctor or pharmacist before taking your medicine if:
- you have stomach cancer
- you have kidney problems. You will need to take a different amount of Zantac
you have had stomach ulcers before and you are taking Non-Steroidal Anti-
Inflammatory (NSAID) medicines
- you have a rare condition called acute porphyria
- you are over 65 years old
- you have lung disease
- you are diabetic
- you have any problems with your immune system.
If you are not sure if any of the above apply to you, talk to your doctor or pharmacist before using this medicine.
Other medicines and Zantac
Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. This includes medicines that you buy without a prescription and herbal medicines. This is because Zantac can affect the way some other medicines work. Also some other medicines can affect the way Zantac works.
In particular tell your doctor or pharmacist if you are taking any of the following medicines:
- Non-Steroidal Anti-Inflammatory (NSAID) medicines, for pain and inflammation
- lidocaine, a local anaesthetic
- propranolol, procainamide or n-acetylprocainamide, for heart problems
- diazepam, for worry or anxiety problems
- phenytoin, for epilepsy
- theophylline, for breathing problems (asthma)
- warfarin, for thinning your blood.
- glipizide, for lowering blood glucose
- atazanavir or delavirdine, for treating HIV infection
- triazolam, for insomnia
- gefitinib, for lung cancer
- ketoconazole, an anti fungal medicine, sometimes used for treating thrush
- erlotinib; for certain types of cancer
- sucralfate, for treating stomach ulcers.
Midazolam is a medicine that may be given to you just before you have an operation. Tell the doctor you are taking Zantac before your operation in case he or she wants to give you midazolam.
If you are taking erlotinib, a drug used for the treatment of certain types of cancer, talk to your doctor before you take Zantac Tablet. Ranitidine contained in Zantac Tablet may decrease the amount of erlotinib in your blood and your doctor may need to adjust your treatment if it is used while you are receiving erlotinib.
If you are not sure if any of the above apply to you, talk to your doctor, pharmacist or nurse before taking Zantac.
Pregnancy, breast-feeding and fertility
If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor, pharmacist or nurse for advice before taking this medicine. You should not take this medicine unless your doctor advises it is essential.
Important information about the contents of Zantac Tablets
300mg Tablets:
This medicine contains less than 1 mmol sodium (23 mg) per dosage unit, that is to say essentially ‘sodium-free’.
3 How to take Zantac Tablets
Always take this medicine exactly as your doctor or pharmacist has told you. You should check with your doctor or pharmacist if you are not sure.
Taking this medicine
- Take this medicine by mouth.
- Swallow each tablet whole with a glass of water.
The usual dose for an adult (including the elderly) is either:
- 150 mg in the morning and 150 mg in the evening, or
- 300 mg at bedtime.
Your exact dose will depend on your particular stomach condition, your doctor will tell you the dose you should take.
Use in children 12 years and over:
The adult dose is given.
Use in children over 30 kg of weight and from 3 to 11 years:
Your doctor will work out the right dose for you based on your child’s weight.
Treatment of stomach or duodenal (small intestine) ulcers:
The usual dose is 2 mg for each kg of body weight, twice a day for four weeks. This dose may be increased to 4 mg for each kg, twice a day. Take each dose about 12 hours apart. The duration of treatment may be increased to 8 weeks.
Treatment of heartburn due to too much acid:
The usual dose is 2.5 mg for each kg of body weight, twice a day for two weeks. This dose may be increased to 5 mg for each kg, twice a day. Take each dose about 12 hours apart.
If you take more Zantac than you should
Zantac is not normally harmful if you take more than you should, unless you take many tablets at once. If this applies to you (or someone else taking this medicine), you should go to your nearest hospital casualty department straight away.
Take the medicine pack or any remaining medicine with you so that the doctor knows what you have taken.
If you forget to take Zantac
- If you forget a dose, take it as soon as you remember it, unless it is nearly time for your next dose.
- Do not take a double dose to make up for a forgotten dose.
If you stop taking Zantac
After a few days of taking the tablets you should start to feel much better. Do not stop taking the tablets without talking to your doctor or pharmacist first, otherwise the original pain and discomfort may come back.
If you have any further questions on the use of this product, ask your doctor or pharmacist.
4 Possible side effects
Like all medicines, this medicine can cause side effects, although not everybody gets them.
The following side effects may happen with this medicine.
Stop taking Zantac and see a doctor straight away, if you notice any of the following serious side effects, you may need urgent medical treatment:
allergic reactions, the signs may include:
- rash, itching or hives on the skin
- swelling of your face, lips, tongue or other parts of the body
- chest pain, shortness of breath, wheezing or having trouble breathing
- unexplained fever and feeling faint, especially when standing up
- kidney problems, which can lead to back pain, fever, pain when passing urine, blood in the urine and changes in blood tests
- severe stomach pain, this may be a sign of something called ‘pancreatitis’
- a slow or irregular heartbeat
Check with your doctor at your next visit if you notice any of the following:
Uncommon (may affect up to 1 in 100 people)
- stomach pain
- constipation
- feeling sick (nausea)
Rare (may affect up to 1 in 1,000 people)
- skin rash
Rare side effects that may show up in blood tests:
- increase of serum creatinine in the blood (kidney function test)
- changes to liver function
Check with your doctor as soon as possible if you notice any of the following: Very rare (may affect up to 1 in 10,000 people)
- there can be changes in the level of certain substances in your blood. This can lead to you feeling unusually tired or short of breath and being more likely to bruise or get an infection
feeling depressed, confused, seeing or hearing unexplained things
(hallucinations)
- headache (sometimes severe)
- feeling dizzy or having blurred vision
- your joints or muscles are painful or swollen or you cannot control their movement
- your small blood vessels can become swollen (known as ‘vasculitis’). Signs of this can include: a rash, swollen joints or kidney problems
your liver can become swollen. This can lead to: nausea (feeling sick) or vomiting
(being sick), loss of appetite or generally feeling unwell, itching, fever, yellowing of the skin and eyes or dark coloured urine
- flushing or marks on your skin that look like targets
- unexplained hair loss
- diarrhoea
- impotence
- breast tenderness and/or breast enlargement
- breast discharge
- awareness of the heart beat and/or increased heart rate
Not known (frequency cannot be estimated from the available data)
- shortness of breath
Reporting of side effects
If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at:
www.mhra.gov.uk/yellowcard
By reporting side effects you can help provide more information on the safety of this medicine. 
5 How to store Zantac
- Keep this medicine out of the sight and reach of children.
- Do not use this medicine after the expiry date which is stated on the label. The expiry date refers to the last day of that month.
- Store below 25oC. Store in the original package in order to protect from moisture
- Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help to protect the environment.
6 Contents of the pack and other information
What Zantac contains:
- The active substance is ranitidine (as the hydrochloride) 150 mg or 300 mg
- The other ingredients are microcrystalline cellulose, magnesium stearate, methylhydroxypropyl cellulose (E464), titanium dioxide (E171) and triacetin. 300 mg tablets also contain croscarmellose sodium.
What Zantac looks like and contents of the pack
Zantac Tablets 150 mg are round, white tablets.
Zantac Tablets 300 mg are white, capsule-shaped tablets.
Cartons contain aluminium foil strips or push through double foil blisters. 150 mg strength cartons contain 60 tablets in strips of 10 and 300 mg strength cartons contain 30 tablets in strips of 5.
Marketing Authorisation Holder and Manufacturer
Product licence held by Glaxo Wellcome UK Ltd, Stockley Park West, Uxbridge, Middlesex UB11 1BT
Manufactured by Glaxo Wellcome S.A., Avenida de Extremadura 3, 09400 Aranda de Duero, Burgos, Spain
The information provided applies only to Zantac Tablets 150 mg and 300 mg
Other sources of information
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0800 198 5000 (UK Only)
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Product name Zantac Tablets 150 mg
Zantac Tablets 300 mg
Reference number 10949/0042
This is a service provided by the Royal National Institute of Blind People.
This leaflet was last revised in August 2019.
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