Flunarizine: What is it? Dosage, Side Effects, Interactions, Warnings and Precautions

It is used to prevent migraine headaches with or without aura (warning signs before the headache begins).

This medication should not be used to treat acute migraine headaches (headaches that have already started).

Flunarizine helps reduce the frequency of migraine attacks and, to a lesser extent, the severity of the attacks. It does not seem to affect how long the episodes last, and this may not be seen for several weeks.

Note: Do not stop taking the medication due to lack of effect within the first six to eight weeks.

Flunarizine, a calcium channel blocker drug, was discovered in 1967 at Janssen Pharmaceutica. It is prescribed to patients with peripheral vascular disease, vertigo, and epilepsy.

Mainly, it is used to prevent migraine attacks in those patients with severe and frequent attacks who do not respond adequately to other treatments that cause unacceptable side effects.

It is also indicated for the symptomatic treatment of vestibular vertigo due to functional disorders of the vestibular system.



Flunarizine is a selective calcium entry blocker with Calmodulin-binding properties and histamine H1-blocking activity.

Mechanism of action

Flunarizine inhibits the influx of extracellular calcium through the pores of the vascular membrane and the myocardium by physically obstructing the channel.

The decrease in intracellular calcium inhibits the contractile processes of smooth muscle cells, causing dilatation of the coronary and systemic arteries, and increased oxygen supply to the myocardial tissue.

Also, they decrease the total peripheral resistance, decrease the systemic arterial pressure, and decrease the post-load.

In summary, Flunarizine works by affecting the movement of calcium, relaxing the blood vessels in the process. It also helps increase the oxygen supply to the heart and decreases its workload.

Start of the action and duration of the effect

The effect of this medication is cumulative and may take weeks to show.

The time this medication remains in effect is subject to vary according to the intended use and the form of administration.

How should I use Flunarizine?

Flunarizine is an oral drug that comes in 10 mg capsules. The usual dose for adults is one capsule per day. For young children, the amount should be arranged directly by your doctor.

Those who have side effects can take 5 mg a day at night.

Flunarizine should be taken at night, with or without food. To reduce the chance of losing a dose, take it at about the same time every day.

Many things can affect the dose of medication a person needs, such as body weight, other medical conditions, and other drugs.

If your doctor has recommended a different dose from the ones listed here, do not change how you take the medication without consulting your doctor.

You must take this medication exactly as prescribed by your doctor. It must be taken regularly for maximum effectiveness.

If you miss a dose, take it as soon as possible and continue your usual schedule. If it is almost time for the next one, skip the missed dose and continue with your regular dosing schedule. Do not take a double amount to make up for the one you forgot.

Do not dispose of medications in wastewater (for example, in the sink or the toilet) or household waste. Ask your pharmacist how to get rid of drugs that are no longer needed or have expired.

Migraine prophylaxis:

Initial dose: treatment starts with 10 mg per day (at night) in patients under 65 years of age and 5 mg per day in patients aged 65 or older.

Suppose during the treatment you experience a depressive state. In that case, you have reactions such as abnormal eye movements, tremors, muscle stiffness, uncontrollable movements of hands, neck, and head or legs, or clumsiness.

Also, if you have mental confusion or any other adverse reaction, immediately consult your doctor, who will probably discontinue treatment with this medication.

If no significant improvement is observed after two months of initial treatment, consult your doctor, who will probably recommend stopping treatment.

Maintenance treatment: if you respond satisfactorily and maintenance treatment is needed, your doctor will reduce the daily dose by administering the initial amount in weekly cycles of 5 days and two days of rest.

Even when preventive maintenance treatment is successful and well-tolerated, it should be discontinued after six months and restarted only if necessary (relapse).

Treatment of vertigo:

It will be administered 10 mg a day (at night) in patients under 65 years and 5 mg a day in patients over 65 years. The treatment will not last longer than the time required to achieve symptom control, which usually occurs before two months.

However, suppose that no improvement is observed after one month of treatment for chronic vertigo or after two months of recurrent vertigo. In that case, it is considered that the patient does not respond to treatment and should be suspended.

If you think the effect of the medicine is too strong or too weak, ask your doctor.

If you have further questions about using this product, consult your doctor or pharmacist.

Who should NOT take this medicine?

No one should take Flunarizine with:

  • Allergy to Flunarizine or any of the ingredients it has.
  • History of depression .
  • History of involuntary movement disorders (extrapyramidal symptoms).

What side effects does this medication cause?

At the start of treatment with Flunarizine, you may experience some side effects, which are normal since your system is still adjusting to the medication.

At least 1% of people taking this medication have reported the following side effects. Many of these effects can be controlled, and some may disappear on their own over time.

  • Drowsiness.
  • Constipation.
  • Diarrhea.
  • Dizziness or lightheadedness
  • Dry mouth.
  • Redness and heat sensation
  • Headache.
  • Increase in appetite or weight gain.
  • Sickness.
  • Unusual tiredness or weakness

Although most of the side effects listed below do not happen very often, they can cause severe problems if you do not see your doctor or seek medical attention.

Serious side effects:

  • Bleeding, sensitive, or swollen gums.
  • Difficulty breathing, coughing or wheezing.
  • Chest pain (may appear approximately 30 minutes after the medicine is taken).
  • Depression.
  • Fainting.
  • Irregular or rapid, strong heartbeat.
  • Loss of balance control.
  • Walk shuffling.
  • Acne.
  • The rigidity of the arms or legs.
  • Swelling of the ankles, feet, or lower legs.
  • General tremor or tremor of hands and fingers.
  • Problems speaking or swallowing
  • Unusual secretion of breast milk.

If you feel that your side effects symptoms dominate the positive effects of Flunarizine, call your doctor immediately.

Are there other precautions or warnings for this medicine?

This medicine, in capsules and tablets, contains lactose. If your doctor has told you that you have an intolerance to certain sugars, contact him before taking it.

Before you start using a medication, tell your doctor about any medical conditions or allergies you may have, any medications you are taking, if you are pregnant or breastfeeding, and any other important health information.

These factors can affect the way you should use this medicine.

Depression: If you experience depression (such as depressed thoughts or mood, lack of interest in everyday activities, changes in sleep, or extreme fatigue), contact your doctor or health care professional immediately.

Drowsiness / reduced alertness: do not operate vehicles or equipment until you know how Flunarizine affects you. Avoid drinking alcohol, as it may increase the potential drowsiness caused by flunarizine.

Glaucoma: This medication should be used with caution in patients with glaucoma. Report any impaired vision, pain, or dry eyes to the doctor immediately.

Heart disease: This medicine should be cautioned in patients with active heart or blood vessel disease.

Liver problems: Tell your doctor if you have ever had liver problems.

Pregnancy: There is little information about the use of this medication during pregnancy. Discuss the risks and benefits with your doctor.

Lactation: Flunarizine passes into breast milk. Nursing women should not use it.

Children: The safety and efficacy of this medication have not been established for children under 18 years of age.

Older adults: the effectiveness of this medication for use by older people has not been established.

Alcohol: Avoid or limit your alcohol intake while using this medication. It is recommended to refrain from driving a vehicle or operating heavy machinery while taking this medication.

What other drugs may interact with this medicine?

There may be an interaction between Flunarizina and any of the following:

  • Alcohol.
  • Anticonvulsants
  • Tranquilizers

If you are taking any of these medications, talk to your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • Stop taking one of the medications.
  • Change one of the medications to another.
  • Change the way you are taking one or both medications.
  • Leave everything like this.