Flunarizine has been used in medical practice for over 25 years. It was initially introduced as a medicine to improve blood flow and is a medicine known as a calcium channel blocker. It has been mainly used in the treatment of dizziness, vertigo and prevention of migraine.
Flunarizine is effective in reducing attack in all forms of migraine but is particularly effective in migraine with severe and disabling neurological symptoms (for instance, migraine with aura or one-sided weakness) with dizziness or vertigo.
Although this medicine is widely used by headache specialists around the world and is licensed in many countries for the prevention of migraine, it should be noted that flunarizine is not marketed nor licensed in the UK. The medicine has to be imported from abroad by a licensed pharmaceutical import company under the brand name Sibelium®.
Medicines are often used ‘off licence’ in children for a number of reasons, however limited data is often available for a specific use in children. This is not necessarily hazardous but should be explained and agreed before use. Your doctor will explain this further to you.
How is flunarizine given?
Flunarizine should be taken at night-time starting with a low dose. This may then be increased as recommended by the doctor.
You should encourage your child to continue with the medicine as it may not take full effect for about eight to 12 weeks. If beneficial, the medicine will usually be used for at least six months but you will be advised further about this by your doctor.
Who should not take flunarizine?
People with the following conditions should discuss taking flunarizine with their doctor.
- hypersensitivity to flunarizine or any of its ingredients
- depression or previous episodes of serious depression
- Parkinson’s disease or a family history of Parkinson’s disease
- liver damage
What are the side effects of flunarizine?
The main side effects of flunarizine are tiredness, drowsiness, weight gain and low mood.
- Tiredness and drowsiness can be reduced by starting with a low dose and taking it at night. The dose will then be increased gradually once your child becomes tolerant to these effects. Some patients experience a second wave of tiredness after several weeks or months and it would be advisable to either try a lower dose or use the medicine on alternate days. This should be discussed with your doctor
- Possible weight gain is caused by an increase in appetite and can be avoided by your child following his or her usual diet without any increase in portion size. In our experience, this happens in one in ten children taking the medicine.
- If your child develops low mood or depressive symptoms, the medicine should be discontinued. You should take advice from your family doctor (GP) whether specific treatment may be necessary for the treatment of depression if the symptoms do not disappear within one month.
There have also been reported cases of flunarizine causing symptoms as seen in Parkinsons’s Disease (extrapyramidal symptoms) which usually disappear when flunarizine is stopped. Other side effects that have been reported include: sickness and upset stomach, insomnia, dry mouth, weakness and muscles aches, and a skin rash. If you are concerned about any of these, please tell your doctor.
Flunarizine and other medicines
Always check with your doctor or pharmacist before giving your child any other medicines, including herbal or complementary medicines. The following are known to interact with flunarizine.
- anti-anxiety medicines
- muscle relaxants
- anti-seizure medicines
Important information about flunarizine
- Keep medicines in a safe place where children cannot reach them.
- The tablets should be kept in a cool, dry place out of direct sunlight and heat.
- As flunarizine has to be imported from abroad, it can take longer to supply than other medicines. Always remember to ask your doctor for a repeat prescription in plenty of time.
- If you forget to give your child a dose and it is within a few hours of when the dose was due, give it as soon as you remember. Otherwise, do not give this dose but give the next dose when it is due. Do not give a double dose.
- If your doctor decides to stop treatment or the tablets pass their expiry date, return any unused tablets to the pharmacist. Do not flush them down the toilet or throw them away.
Please read this information sheet from GOSH alongside the patient information leaflet (PIL) provided by the manufacturer. If you do not have a copy of the manufacturer’s patient information leaflet please talk to your pharmacist. A few products do not have a marketing authorisation (licence) as a medicine and therefore there is no PIL.
For children in particular, there may be conflicts of information between the manufacturer’s patient information leaflet (PIL) and guidance provided by GOSH and other healthcare providers. For example, some manufacturers may recommend, in the patient information leaflet, that a medicine is not given to children aged under 12 years. In most cases, this is because the manufacturer will recruit adults to clinical trials in the first instance and therefore the initial marketing authorisation (licence) only covers adults and older children.
For new medicines, the manufacturer then has to recruit children and newborns into trials (unless the medicine is not going to be used in children and newborns) and subsequently amend the PIL with the approved information. Older medicines may have been used effectively for many years in children without problems but the manufacturer has not been required to collect data and amend the licence. This does not mean that it is unsafe for children and young people to be prescribed such a medicine ‘off-licence/off-label’. However, if you are concerned about any conflicts of information, please discuss with your doctor, nurse or pharmacist.