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Zydol SR 50 mg prolonged-release Tablets

Active Ingredient:
tramadol hydrochloride
Grunenthal Ltd See contact details
ATC code: 
About Medicine
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine.
Last updated on emc: 31 May 2024

Below is a text only representation of the Patient Information Leaflet (ePIL).

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on {phone} 0800 198 5000. The product code(s) for this leaflet is: PL 50414/0023.

Zydol SR 50mg Tablets

Package leaflet: Information for the user

ZYDOL SR 50 mg, prolonged-release tablets

Tramadol hydrochloride

Read all of this leaflet carefully before you start taking this medicine because it contains important information for you.
  • Keep this leaflet. You may need to read it again.
  • If you have any further questions, ask your doctor or pharmacist.
  • This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.
  • If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet (see section 4).

What is in this leaflet:

1. What ZYDOL SR is and what it is used for
2. What you need to know before you take ZYDOL SR
3. How to take ZYDOL SR
4. Possible side effects
5. How to store ZYDOL SR
6. Contents of the pack and other information

1. What ZYDOL SR is and what it is used for

Tramadol - the active substance in ZYDOL SR - is a painkiller belonging to the class of opioids that acts on the central nervous system. It relieves pain by acting on specific nerve cells of the spinal cord and brain.

ZYDOL SR is used for the treatment of moderate to severe pain.

2. What you need to know before you take ZYDOL SR
Do not take ZYDOL SR
  • if you are allergic to tramadol or any of the other ingredients of this medicine (listed in section 6);
  • in acute poisoning with alcohol, sleeping pills, pain relievers or other psychotropic medicines (medicines that affect mood and emotions);
  • if you are also taking MAO inhibitors (certain medicines used for treatment of depression) or have taken them in the last 14 days before treatment with ZYDOL SR (see "Other medicines and ZYDOL SR");
  • if you are an epileptic and your fits are not adequately controlled by treatment;
  • as a substitute in drug withdrawal.

Warnings and precautions

Talk to your doctor before taking ZYDOL SR, if

  • you suffer from consciousness disorders (if you feel that you are going to faint);
  • you are in a state of shock (cold sweat may be a sign of this);
  • you suffer from increased pressure in the brain (possibly after a head injury or brain disease);
  • you have difficulty in breathing;
  • you have a tendency towards epilepsy or fits because the risk of a fit may increase;
  • you suffer from depression and you are taking antidepressants as some of them may interact with tramadol (see “Other medicines and ZYDOL SR”);
  • you suffer from a liver or kidney disease;

Tolerance, dependence, and addiction

This medicine contains tramadol which is an opioid medicine. Repeated use of opioids can result in the drug being less effective (you become accustomed to it, known as tolerance).

Repeated use of ZYDOL SR can also lead to dependence, abuse and addiction, which may result in life-threatening overdose. The risk of these side effects can increase with a higher dose and longer duration of use.

Dependence or addiction can make you feel that you are no longer in control of how much medicine you need to take or how often you need to take it.

The risk of becoming dependent or addicted varies from person to person. You may have a greater risk of becoming dependent on or addicted to ZYDOL SR if:

  • You or anyone in your family have ever abused or been dependent on alcohol, prescription medicines or illegal drugs (“addiction”).
  • You are a smoker.
  • You have ever had problems with your mood (depression, anxiety, or a personality disorder) or have been treated by a psychiatrist for other mental illnesses.

If you notice any of the following signs whilst taking ZYDOL SR, it could be a sign that you have become dependent or addicted:

  • You need to take the medicine for longer than advised by your doctor
  • You need to take more than the recommended dose
  • You are using the medicine for reasons other than prescribed, for instance, ‘to stay calm’ or ‘help you sleep’
  • You have made repeated, unsuccessful attempts to quit or control the use of the medicine
  • When you stop taking the medicine you feel unwell, and you feel better once taking the medicine again (‘withdrawal effects’)

If you notice any of these signs, speak to your doctor to discuss the best treatment pathway for you, including when it is appropriate to stop and how to stop safely (See section 3, If you stop taking ZYDOL SR.

Sleep-related breathing disorders

ZYDOL SR contains an active substance that belongs to the group of opioids. Opioids can cause sleep-related breathing disorders, for example central sleep apnea (shallow/pause of breathing during sleep) and sleep-related hypoxemia (low level of oxygen in the blood).

The risk of experiencing central sleep apnea is dependent on the dose of opioids. Your doctor may consider decreasing your total opioid dosage if you experience central sleep apnea.

There is a small risk that you may experience a so-called serotonin syndrome that can occur after having taken tramadol in combination with certain antidepressants or tramadol alone. Seek medical advice immediately if you have any of the symptoms related to this serious syndrome (see section 4 “Possible side effects”).

Epileptic fits have been reported in patients taking tramadol at the recommended dose level. The risk may be increased when doses of tramadol exceed the recommended upper daily dose limit (400 mg).

Please note that ZYDOL SR may lead to physical and psychological addiction. When ZYDOL SR is taken for a long time, its effect may decrease, so that higher doses have to be taken (tolerance development). In patients with a tendency to abuse medicines or who are dependent on medicines, treatment with ZYDOL SR should only be carried out for short periods and under strict medical supervision.

Please also inform your doctor if one of these problems occurs during ZYDOL SR treatment or if they applied to you in the past.

Tramadol is transformed in the liver by an enzyme. Some people have a variation of this enzyme and this can affect people in different ways. In some people, they may not get enough pain relief but other people are more likely to get serious side effects. If you notice any of the following side effects, you must stop taking this medicine and seek immediate medical advice: slow or shallow breathing, confusion, sleepiness, small pupils, feeling or being sick, constipation, lack of appetite.

Talk to your doctor if you experience any of the following symptoms while taking ZYDOL SR:

Extreme fatigue, lack of appetite, severe abdominal pain, nausea, vomiting or low blood pressure. This may indicate that you have adrenal insufficiency (low cortisol levels). If you have these symptoms, contact your doctor, who will decide if you need to take hormone supplement.

Other medicines and ZYDOL SR

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.

ZYDOL SR should not be taken together with MAO inhibitors (certain medicines for the treatment of depression).

The pain-relieving effect of ZYDOL SR may be reduced and the length of time it acts may be shortened, if you take medicines which contain

  • carbamazepine (for epileptic fits)
  • ondansetron (prevents nausea).

Your doctor will tell you whether you should take ZYDOL SR, and which dose.

The risk of side effects increases,

  • if you are taking other pain relievers such as morphine and codeine (also as cough medicine), and alcohol while you are taking ZYDOL SR. You may feel drowsier or feel that you might faint. If this happens tell your doctor.
  • Concomitant use of ZYDOL SR and tranquillizers or sleeping pills (e.g. benzodiazepines) or gabapentin or pregabalin to treat epilepsy or pain due to nerve problems (neuropathic pain) increases the risk of drowsiness, difficulties in breathing (respiratory depression), coma or may be life-threatening. Because of this, concomitant use should only be considered when other treatment options are not possible. However, if your doctor prescribes ZYDOL SR together with sedating medicines the dose and the duration of concomitant treatment should be limited by your doctor. Please tell your doctor about all sedating medicines you are taking, and follow your doctor’s dose recommendation closely. It could be helpful to inform friends or relatives to be aware of the signs and symptoms stated above. Contact your doctor when experiencing such symptoms.
  • if you are taking medicines which may cause convulsions (fits), such as certain antidepressants or antipsychotics. The risk having a fit may increase if you take ZYDOL SR at the same time. Your doctor will tell you whether ZYDOL SR is suitable for you.
  • if you are taking certain antidepressants, ZYDOL SR may interact with these medicines and you may experience serotonin syndrome (see section 4 “Possible side effects”).
  • if you are taking coumarin anticoagulants (medicines for blood thinning), e.g. warfarin, together with ZYDOL SR. The effect of these medicines on blood clotting may be affected and bleeding may occur.

ZYDOL SR with food and alcohol

Do not drink alcohol during treatment with ZYDOL SR as its effect may be intensified. Food does not influence the effect of ZYDOL SR.

Children and adolescents

Use in children with breathing problems:

Tramadol is not recommended in children with breathing problems, since the symptoms of tramadol toxicity may be worse in these children.

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 or pharmacist for advice before taking this medicine.

There is very little information regarding the safety of tramadol in human pregnancy. Therefore you should not use ZYDOL SR if you are pregnant.

Chronic use during pregnancy may lead to withdrawal symptoms in newborns.

Tramadol is excreted into breast milk. For this reason, you should not take Zydol SR more than once during breast-feeding, or alternatively, if you take Zydol SR more than once, you should stop breast-feeding. Based on human experience tramadol is suggested not to influence female or male fertility.

Driving and using machines

ZYDOL SR may cause drowsiness, dizziness and blurred vision and therefore may impair your reactions. If you feel that your reactions are affected, do not drive a car or other vehicle, do not use electric tools or operate machinery.

This medicine can affect your ability to drive.

Do not drive whilst taking this medicine until you know how this medicine affects you.

It may be an offence to drive if your ability to drive safely is affected.

There is further information for patients who are intending to drive in Great Britain - go to

ZYDOL SR contains lactose

If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicinal product. This is because the tablets contain lactose.

3. How to take ZYDOL SR

Always take this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure.

Before starting treatment and regularly during treatment, your doctor will discuss with you what you may expect from using ZYDOL SR, when and how long you need to take it, when to contact your doctor, and when you need to stop it (see also section 2).

The dosage should be adjusted to the intensity of your pain and your individual pain sensitivity. In general the lowest pain-relieving dose should be taken. Do not take more than 400 mg tramadol hydrochloride daily, except if your doctor has instructed you to do so.

Unless otherwise prescribed by your doctor, the usual dose is:

Adults and adolescents from the age of 12 years

One or two ZYDOL SR 50 mg prolonged-release tablets twice daily (equivalent to 100 mg - 200 mg tramadol hydrochloride per day), preferably in the morning and evening.

Your doctor may prescribe a different, more appropriate dosage strength of ZYDOL SR if necessary.

If necessary, the dose may be increased up to 150 mg or 200 mg twice daily (equivalent to 300 mg – 400 mg tramadol hydrochloride per day).


ZYDOL SR is not suitable for children below the age of 12 years.

Older people

In older people (above 75 years) the excretion of tramadol may be delayed. If this applies to you, your doctor may recommend prolonging the dosage interval.

Severe liver or kidney disease (insufficiency)/dialysis patients

Patients with severe liver and/or kidney insufficiency should not take ZYDOL SR. If in your case the insufficiency is mild or moderate, your doctor may recommend prolonging the dosage interval.

How and when should you take ZYDOL SR?

ZYDOL SR prolonged-release tablets are for oral use.

Always swallow ZYDOL SR prolonged-release tablets whole, not divided or chewed, with sufficient liquid, preferably in the morning and evening. You may take the tablets on an empty stomach or with meals.

How long should you take ZYDOL SR?

You should not take ZYDOL SR for longer than necessary. If you need to be treated for a longer period, your doctor will check at regular short intervals (if necessary with breaks in treatment) whether you should continue to take ZYDOL SR and at what dose.

If you have the impression that the effect of ZYDOL SR is too strong or too weak, talk to your doctor or pharmacist.

If you take more ZYDOL SR than you should

If you have taken an additional dose by mistake, this will generally have no negative effects. You should take your next dose as prescribed.

After taking very high doses, pin-point pupils, vomiting, fall in blood pressure, fast heart beat, collapse, disturbed consciousness up to coma (deep unconsciousness), epileptic fits, and difficulty in breathing up to cessation of breathing may occur. In such cases a doctor should be called immediately!

If you forget to take ZYDOL SR

If you forget to take the tablets, pain is likely to return. Do not take a double dose to make up for forgotten individual doses, simply continue taking the tablets as before.

If you stop taking ZYDOL SR

If you interrupt or finish treatment with ZYDOL SR too soon, pain is likely to return. If you wish to stop treatment on account of unpleasant effects, please tell your doctor.

You should not suddenly stop taking this medicine unless your doctor tells you to. If you want to stop taking your medicine, discuss this with your doctor first, particularly if you have been taking it for a long time. Your doctor will advise you when and how to stop, which may be by lowering the dose gradually to reduce the chance of developing unnecessary side effects (withdrawal symptoms).

Generally there will be no after-effects when treatment with ZYDOL SR is stopped. However, on rare occasions, people who have been taking ZYDOL SR prolonged-release tablets for some time may feel unwell if they abruptly stop taking them. They may feel agitated, anxious, nervous or shaky. They may be hyperactive, have difficulty sleeping and have stomach or bowel disorders. Very few people may get panic attacks, hallucinations, unusual perceptions such as itching, tingling and numbness, and noise in the ears (tinnitus). Further unusual CNS symptoms, i.e. confusion, delusions, change of perception of the own personality (depersonalisation), and change in perception of reality (derealisation) and delusion of persecution (paranoia) have been seen very rarely. If you experience any of these complaints after stop taking ZYDOL SR, please consult your doctor.

If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

You should see a doctor immediately if you experience symptoms of an allergic reaction such as swollen face, tongue and/or throat and/or difficulty swallowing or hives together with difficulties in breathing.

The most common side effects during treatment with ZYDOL SR are nausea and dizziness, which occur in more than 1 in 10 people.

Very common: may affect more than 1 in 10 people

  • dizziness.
  • nausea.

Common: may affect up to 1 in 10 people

  • headaches, drowsiness.
  • fatigue.
  • constipation, dry mouth, vomiting.
  • sweating (hyperhidrosis).

Uncommon: may affect up to 1 in 100 people

  • effects on the heart and blood circulation (pounding of the heart, fast heartbeat, feeling faint or collapse). These adverse effects may particularly occur in patients in an upright position or under physical strain.
  • urge to vomit (retching), stomach trouble (e.g. feeling of pressure in the stomach, bloating), diarrhoea.
  • skin reactions (e.g. itching, rash).

Rare: may affect up to 1 in 1,000 people

  • allergic reactions (e.g. difficulty in breathing, wheezing, swelling of skin) and shock (sudden circulation failure) have occurred in very rare cases.
  • slow heartbeat.
  • increase in blood pressure.
  • abnormal sensations (e.g. itching, tingling, numbness), trembling, epileptic fits, muscle twitches, uncoordinated movement, transient loss of consciousness (syncope), speech disorders.
  • epileptic fits have occurred mainly at high doses of tramadol or when tramadol was taken at the same time as other medicines which may induce fits.
  • changes in appetite.
  • hallucination, confusional state, sleep disorders, delirium, anxiety and nightmares.
  • psychological complaints may appear after treatment with ZYDOL SR. Their intensity and nature may vary (according to the patient's personality and length of therapy). These may appear as a change in mood (mostly high spirits, occasionally irritated mood), changes in activity (usually suppression, occasionally increase) and decreased cognitive and sensory perception (changes in senses and recognition, which may lead to errors in judgment).
  • drug dependence may occur.
  • vision blurred, constriction of the pupil (miosis), excessive dilation of the pupils (mydriasis).
  • slow breathing, shortness of breath (dyspnoea).
  • worsening of asthma has been reported, however it has not been established whether it was caused by tramadol. If the recommended doses are exceeded, or if other medicines that depress brain function are taken at the same time, breathing may slow down.
  • weak muscles.
  • passing urine with difficulty or pain, passing less urine than normal (dysuria).

Very rare: may affect up to 1 in 10,000 people

  • hepatic enzyme increased.

Not known: frequency cannot be estimated from the available data

  • decrease in blood sugar level.
  • hiccups.

Serotonin syndrome, that can manifest as mental status changes (e.g. agitation, hallucinations, coma), and other effects, such as fever, increase in heart rate, unstable blood pressure, involuntary twitching, muscular rigidity, lack of coordination and/or gastrointestinal symptoms (e.g. nausea, vomiting, diarrhoea) (see section 2 “What you need to know before you take ZYDOL SR”).

When treatment is stopped abruptly signs of drug withdrawal syndrome may appear (see “If you stop taking ZYDOL SR”).

Reporting of side effects

If you get any side effects talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via:


HPRA Pharmacovigilance


The Yellow Card Scheme at: or search for MHRA Yellow Card in the Google Play or Apple App Store.

By reporting side effects, you can help provide more information on the safety of this medicine.

5. How to store ZYDOL SR

Keep this medicine out of the sight and reach of children.

Store this medicine in a safe and secure storage space, where other people cannot access it. It can cause serious harm and be fatal to people when it has not been prescribed for them.

Do not use this medicine after the expiry date which is stated on the carton and the blister. The expiry date refers to the last day of that month. This medicinal product does not require any special storage conditions.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away any medicines you no longer use. These measures will help protect the environment.

6. Contents of the pack and other information
What ZYDOL SR contains

The active substance is tramadol hydrochloride.

ZYDOL SR 50 mg, prolonged-release tablets:

Each tablet contains 50 mg tramadol hydrochloride.

The other ingredients are:

Tablet core: microcrystalline cellulose, hypromellose 100 000 mPa·s, magnesium stearate, colloidal anhydrous silica.

Film coating: hypromellose 6 mPa·s, lactose monohydrate (see section 2 “ZYDOL SR contains lactose”), macrogol 6000, propylene glycol, talc, titanium dioxide (E 171), yellow iron oxide (E 172).

What ZYDOL SR looks like and contents of the pack

ZYDOL SR 50 mg prolonged-release tablets are round, biconvex pale yellow coloured film-coated tablets marked with the manufacturer’s logo ♎︎ on one side, marked T0 on the other side.

ZYDOL SR 50 mg prolonged-release tablets are packed in blister strips and are supplied in boxes of 10, 20, 30, 50, 60, 100 and 150 (10x15) tablets.

Not all pack sizes may be marketed.

Marketing Authorisation Holder and Manufacturer

Marketing Authorisation Holder:

Grünenthal Pharma Ltd
4045 Kingswood Road
Citywest Business Park
Co. Dublin


Grünenthal GmbH
Zieglerstr. 6

This medicinal product is authorised in the Member States of the E.E.A. under the following names:

Germany Nobligan retard 50 mg

Ireland Zydol SR 50 mg

United Kingdom (Northern Ireland) Zydol SR 50 mg

This leaflet was last revised in:

May 2024

UK Only

To listen to or request a copy of this leaflet in Braille, large print or audio please call, free of charge:

0800 198 5000

Please be ready to give the following information:

Product name Reference number

Zydol SR 50 mg prolonged-release tablets PL 50414/0023

This is a service provided by the Royal National Institute of Blind People.

Grunenthal Ltd
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