Do not take Centrax:

• If you are allergic to prazepam or other similar benzodiazepine medicines
• If you suffer from an autoimmune disease called ‘myasthenia gravis’ where you suffer from very weak and tired muscles
• If you have severe breathing difficulties
• If you have severe liver problems
• If you have ‘sleep apnoea’- this is a condition where your breathing becomes irregular, even
  stopping for short periods, while you are asleep.

Warning and precautions

• Talk to your doctor or pharmacist before taking Centrax.
• Your doctor will assess your condition before and throughout your treatment with this medicine.
• Centrax tablets are for short term use only for over a period of 4 to 6 weeks. Your condition will be reviewed if you need more than the recommended duration of treatment. Your dose will be lowered gradually as you progress through the course of this treatment. If you take Centrax for a long period of time, you may need to have regular blood tests.
• Centrax may cause memory loss in some patients several hours after taking the tablets. If you believe that you could have suffered memory loss after taking Centrax tell your doctor. To reduce this risk your doctor may recommend that you take this medicine at a time which ensures you have 7 to 8 hours of uninterrupted sleep.
• Tell your doctor immediately if you notice a change in your behaviour, for example agitation, rage, aggressiveness, false beliefs and hallucinations, inappropriate actions and restlessness, as your treatment may need to be discontinued.
• History of dependence
• If you have a history of alcohol or drugs abuse, your doctor may want to give you special help when you need to stop taking these tablets.

Tell your doctor if you start to experience the following during your treatment with this medicine:

• a decrease in the effects of the medicine
• feeling of dependence on your treatment (withdrawal symptoms) if you delay or miss
  taking your tablets
• lack of sleep and increased anxiety.

Centrax needs to be gradually reduced towards the end of your treatment. Do not stop taking your tablets suddenly, especially if you have been taking a high dose. You may experience withdrawal symptoms (“rebound effects”) like headache, depression, nervousness, feeling stressed or worried, difficulty in sleeping, restlessness, irritability, tension and muscle pain.

Elderly Patients

Centrax may cause the muscles to feel relaxed or weak, therefore elderly patients taking Centrax are more at risk of falling, which may lead to hip fractures. Elderly patients should therefore take care when moving around if they experience any muscles problems.

Other medicines and Centrax

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicine, in particular any of the following medicines, as the effect of Centrax may be stronger when taken at the same time. Sometimes it may be necessary to reduce the dose of Centrax if you are taking:

• any other medicines to treat anxiety or depression or to help you sleep
• strong pain killers (e.g. opioids, morphine or codeine - keep the dosages and duration of both medicines to a minimum as recommended by your doctor). Taking Centrax with these pain killers may make you more sleepy and in rare cases can cause breathing difficulty and death.
• antipsychotic medicines such as clozapine - used to treat mental illnesses like schizophrenia
  which affects the way you think and feel
• medicines to treat epilepsy
• sedative antihistamines for relief of allergies that also make you sleepy
• oral contraceptives (‘the pill’)
• anaesthetics (medicines that aid loss of sensation to prevent pain during surgery).

Centrax with food and drink

Do not drink any alcohol whilst you are taking Centrax, as alcohol increases the effects of this medicine.

Pregnancy

Centrax is not recommended during pregnancy and in women of childbearing potential not using birth control. If you are pregnant, think you may be pregnant or are planning to have a baby ask your doctor or pharmacist for advice before taking this medicine.
If you do become pregnant while taking this medicine, your doctor will advise you of the risks involved and may advise you to stop taking the tablets. Occasionally, your doctor may assess your condition and it may be necessary to give you Centrax during late pregnancy or during labour. In these cases babies may have a low body temperature, floppiness, withdrawal symptoms, breathing and feeding difficulties.

Breast-feeding

Do not breast-feed while taking Centrax, as the drug may pass into breast milk.

Driving and using machines

Centrax can cause blurred vision, drowsiness during the day, lack of coordination, forgetfulness and loss of concentration. It is very important you do not drive or operate machinery until you know how the tablets affect you.

Centrax contains lactose

Centrax contains an ingredient known as lactose which is a type of sugar. If you have been told by your doctor that you have an intolerance to some sugars contact your doctor before taking this medicine.

How to take Centrax

• Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. Your doctor will tell you how many tablets to take and when to take them. This information is also on the label on the carton of the tablets. Do not take your tablets with alcohol.
• Your doctor will have decided on the most suitable dose for you. The recommended dose is 3 tablets a day, either as a single dose or divided into several doses. Your doctor may decide that a different dose is right for you; this will normally be between 1 and 6 tablets a day.
• You may be given half the adult dose if you are elderly (over 65), run down, or have kidney or liver problems.
• Centrax is not recommended for the treatment of children or adolescents under 18 years.

Length of treatment and stopping treatment with Centrax tablets

• Centrax tablets are only used for short-term treatment (not more than 6 weeks). You will be given a prescription for this medicine for a minimum of 4 weeks. Your doctor will assess your condition after this time and may put you on a further 2 weeks of treatment.
• Always see your doctor before you stop taking your tablets as the dose needs to be reduced gradually. If you stop taking the tablets or reduce the dose suddenly you can get ‘rebound’ effects which might cause you to become temporarily more anxious or restless or to have difficulty sleeping. These symptoms will go away as your body re-adjusts.

Reasons to see your doctor immediately

Very occasionally treatment with this medicine may cause serious behavioural or psychiatric effects - for example agitation, restlessness, aggressiveness, irritability, violent anger, false beliefs, nightmares or vivid dreams and hallucinations or other inappropriate behaviour. If you get any of these symptoms see your doctor straight away as treatment will need to be discontinued. Your doctor will then advise how treatment will be stopped.

Dependence and withdrawal symptoms

It is possible to become reliant (‘dependent’) on medicines like Centrax while you are taking them which increase the likelihood of getting withdrawal symptoms when you stop treatment. Tell your doctor if you start to feel dependence on your treatment. Withdrawal symptoms are more common if you stop treatment suddenly, have been taking high doses, have been taking Centrax for longer than recommended or have a history of alcohol or drug abuse. This can cause effects such as headaches, muscle pain, extreme anxiety, tension, restlessness, confusion, mood changes, difficulty sleeping and irritability.

In severe cases of withdrawal you can also get the following symptoms: nausea (feeling sick), vomiting, sweating, stomach cramps, muscle cramps, a feeling of unreality or detachment, being unusually sensitive to sound, light or physical contact, numbness and tingling of the feet and hands, hallucinations (seeing or hearing things which are not there while you are awake), shaking or epileptic fits. Please see your doctor as soon as you can if any withdrawal symptoms get worse or don’t go away.

Other side effects

You can also get the following side effects - but you do not need to stop taking the tablets unless your symptoms are very bad. Talk to your doctor if you are at all concerned about any side effects: drowsiness during the day, numbed emotions, confusion, memory loss (tell your doctor if you think you could have suffered this. Your doctor may
recommend that you take this medicine at a time which ensures you have 7 to 8 hours of
uninterrupted sleep), loss of alertness or concentration, tiredness, headache, dizziness, light-headedness, muscle spasms or muscle weakness , double or blurred vision, shakiness or trembling, slurred speech, awareness of your heart beat (palpitations), hyperactivity, dry mouth, sweating, itching or skin reactions, swollen feet, joint pains, fainting, difficulty urinating or bladder control problems, difficulty in controlling movements (ataxia), stomach or intestinal problems, low blood pressure, increase in weight, abnormal liver function tests, changes in libido.

References

https://www.hpra.ie/img/uploaded/swedocuments/LicenseSPC_PA0822-010-001_29012018131039.pdf

https://www.medicines.ie/medicines/centrax-tablets-31593/patient-info

https://www.hpra.ie/img/uploaded/swedocuments/2195359.PA0822_010_001.220ce75e-d945-4586-a905-74c6841927bc.000001Centrax%20PIL.180129.pdf

https://www.therecoveryvillage.com/centrax-addiction/side-effects/#gref

https://www.drugs.com/international/centrax.html

https://www.galenreasoner.com/monographs/7513/usage