Frego

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Frego

Method of action: Other Nervous System Drugs

Treatment option:

Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Frego

Quick Facts: Frego (Flunarizine)

Property Description
Active Ingredient Flunarizine
Form Tablets or Capsules (Oral)
Pharmacological Class Selective Calcium Channel Blocker (CCB)
General Purpose Prophylactic Agent / Maintenance Therapy
Origin Synthetic Compound (Piperazine Derivative)

What is Frego and What is its Core Composition?

Frego is an oral prescription medication whose active substance is Flunarizine, which is chemically classified as a piperazine derivative and pharmacologically categorized as a selective calcium channel blocker (CCB). The drug is a synthetic, single-ingredient product.

The medication's fundamental identity is defined by the sole active pharmaceutical ingredient, Flunarizine, delivered with inert solid oral excipients necessary for the tablet or capsule form. Flunarizine is categorized as an antivertigo preparation with an established chemical structure and therapeutic recognition.


Flunarizine's Pharmacological Class and Prophylactic Role

Flunarizine functions as a highly selective Ca^2+-entry blocker within the CCB class. The primary overall purpose of Frego is to act as a prophylactic agent for maintenance therapy.

This selectivity allows the drug to focus on inhibiting the excessive influx of calcium ions into cells, especially those of vascular smooth muscle, protecting them under conditions of cellular stress or reduced oxygen supply. The medication is designated as a selective voltage-dependent calcium channel inhibitor, which indicates that the medicine is designed to stabilize physiological conditions over time.


The Principle of Selective Cellular and Vascular Stabilization

Flunarizine's high-level mechanism centers on Vascular Protection and Cellular Overload Prevention. The compound prevents undue vasoconstriction and stabilizes cell membranes, which helps to maintain the integrity of the vascular system and improves microcirculatory function.

This specialized stabilizing property, which is distinct from many first-generation CCBs due to its moderate antihistaminic and serotonin receptor blocking activity, allows the drug to function as a cerebrovascular agent, protecting tissue viability throughout the duration of maintenance treatment.

Regulatory References

  1. World Health Organization (WHO)
  2. WHO Model Lists of Essential Medicines

What side effects are possible with Frego?

Possible Side Effects and Safety Information

The description of possible side effects and safety characteristics for Flunarizine (Frego) is based strictly on classifications and frequency data detailed within official governmental regulatory documentation. This information is organized by system-organ class and documented frequency.


Officially Documented Adverse Reactions

Adverse reactions are categorized by regulatory authorities to reflect their likelihood of occurrence. Weight increase is documented as a very common side effect. Common reactions include effects on the central nervous system, such as drowsiness/somnolence, depression, and insomnia.

Less frequent, uncommon reactions may involve the gastrointestinal and musculoskeletal systems, with reported instances of gastric pain, nausea, and myalgia (muscle pain). Fatigue is also classified within the uncommon category.


Serious and Contextual Safety Considerations

Regulatory documents highlight the potential for certain serious adverse reactions, particularly involving the nervous system and mood:

  • Serious Adverse Reactions: The medication is associated with the potential for extrapyramidal symptoms (movement disorders like parkinsonism) and the development of severe depression.

  • Duration-Related Risk: The official label notes that the risk of extrapyramidal symptoms and weight increase is higher with long-term treatment. Conversely, effects like drowsiness are more commonly observed at the beginning of treatment.

  • Population-Specific Safety: An increased risk of extrapyramidal symptoms is specifically noted for older adults (over 65 years of age). Furthermore, the regulatory label explicitly states that Flunarizine should not be used in individuals with severe hepatic (liver) impairment.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory documentation for Frego (Flunarizine) specifies the clinical manifestations and the mandatory emergency actions required in the event of an overdose. The reported clinical profile, observed in cases of acute overdosage, primarily involves the Central Nervous System (CNS) and the Cardiovascular System.

Documented Manifestations and Outcomes

The recognized signs and symptoms documented in regulatory sources include sedation, severe drowsiness, confusion, and agitation. Other documented findings are tachycardia (fast heartbeat) and general weakness or asthenia. The presence of profound CNS effects indicates a potential for Severe CNS Depression, particularly in reports involving single intakes up to 600 mg.

Mandated Emergency Action and Management

Regulatory guidance mandates that medical help must be sought immediately upon the suspicion of an overdose. The situation requires urgent hospital treatment, and contacting emergency services without delay is required. As no specific antidote is known for Flunarizine, the management is strictly symptomatic and supportive.

Procedures described in official labeling include decontamination measures such as charcoal administration and potentially gastric lavage or the induction of emesis, followed by continuous clinical observation and supportive care.

Therapeutic Uses of Frego

Frego (Flunarizine) is a medication generally used for prophylactic maintenance therapy, meaning it is applied long-term to help prevent certain recurrent and disruptive symptom patterns. It is considered relevant for managing conditions like migraine prophylaxis and vertigo of central and peripheral origin. The medication is utilized within these therapeutic domains.


Reducing the Symptom Load in Chronic Conditions

Frego is commonly prescribed for the prevention of migraine headache attacks in patients who experience episodes that are severe in intensity and occur with high frequency, as well as for treating symptoms of chronic dizziness and vestibular disorders. The approach is relevant for managing the impact of throbbing, pulsating pain and may assist with reducing the frequency of attacks. For patients dealing with unsteadiness and spinning sensations, the medication is applied in addressing the need for symptomatic stabilization.

“This therapy plays a role in managing symptoms associated with severe, recurrent episodes, aiming to contribute to improved comfort during symptomatic periods.”


Quick Fact: Relief for Recurrent Symptoms
Main Therapeutic Focus Prevention of frequent, severe migraine and chronic vertigo symptoms.
Symptom Type Addressed Episodic headache pain and persistent balance issues.
Use Classification Supportive, long-term prophylactic management.

Frego is applied in addressing these recurrent and disruptive manifestations. It supports general well-being during symptomatic phases and assists with maintaining functional stability when symptoms are more noticeable.

Regulatory References

  1. National Institutes of Health MeSH Overview

Eligibility and Restrictions for Use

Who can and cannot use Frego (Flunarizine)

The eligibility profile for Frego is strictly defined by regulatory authorities based on age, physiological status, and pre-existing medical conditions.


Populations for Whom Use is Contraindicated

Flunarizine is contraindicated (must not be used) in patients with:

  • Known hypersensitivity to the drug or its components.
  • A history of depressive illness or recurrent depression.
  • Pre-existing symptoms of Parkinson's disease or other extrapyramidal disorders.

Age-Group and Conditional Restrictions

Population Group Regulatory Status
Adults (18+ ) Established population for use.
Pediatrics (<18) Not Recommended. Safety and efficacy have not been established.
Older Adults Use requires Caution. Safety is not established, and this group is at higher risk for movement disorders and depression.
Hepatic Impairment Use requires Caution due to the drug's metabolism by the liver.
Pregnancy Not Recommended. Should not be administered unless benefits clearly outweigh risks.
Lactation Prohibited. Breastfeeding women must not use the medicine as it is excreted into milk.

The official labeling classifies the vast majority of non-eligible users into absolute contraindications or specific use not established categories, ensuring that administration is limited to adults without contraindicating neurological or psychiatric history. The use of formulations containing lactose is also restricted in patients with diagnosed galactose intolerance.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory information for Flunarizine (Frego) documents interactions primarily involving effects on drug exposure and additive central nervous system (CNS) effects.

Interaction Scope

Category Official Regulatory Statement
Medicinal product categories with documented interactions CNS depressants (e.g., hypnotics, tranquilizers), Anti-epileptic drugs (AEDs), Anti-hypertensive drugs.
Specific interacting medicines (if explicitly listed) Carbamazepine, Phenytoin, Topiramate.
Mechanistic basis of interactions Hepatic enzyme induction (Carbamazepine, Phenytoin) reducing Flunarizine exposure; Pharmacodynamic (additive CNS depression); Potential altered oral contraceptive efficacy.
Timing-based interaction rules No mandatory timing separation is formally specified in regulatory documents.
Interaction-related restrictions Use with alcohol is restricted due to the potential for excessive drowsiness.

Official Interaction Statements

  • Co-administration with enzyme-inducing anti-epileptic drugs, such as Carbamazepine or Phenytoin, results in generally lower plasma concentrations of Flunarizine, a pharmacokinetic interaction that reduces the drug's overall exposure.
  • Simultaneous use with alcohol, hypnotics, or tranquilizers may result in excessive sedation due to a documented additive pharmacodynamic effect on the central nervous system.
  • Chronic co-administration with Topiramate may result in a slight increase in the systemic exposure to Flunarizine (up to 16%).
  • Reports exist of galactorrhoea in some female patients on oral contraceptives within the first two months of Flunarizine co-administration.

Connection to the overall interaction profile

Regulatory documents define the product's interaction structure through two main patterns: a pharmacokinetic interaction where specific anti-epileptic drugs reduce its exposure, and a pharmacodynamic interaction leading to enhanced CNS depressant effects when combined with sedating substances. The official label specifies these interacting agents and the resulting exposure or effect modification, defining regulatory constraints for use.

Mechanism of Action

Selective Calcium Channel Modulation

Frego acts as a selective calcium entry blocker, primarily targeting voltage-dependent calcium channels. This action limits the influx of extracellular calcium ions ( Ca^2+) into smooth muscle cells and neurons, which in turn reduces intracellular calcium levels. This core mechanism limits overactive cellular signaling by decreasing neuronal excitability and promoting the relaxation of smooth muscle. This action influences vascular smooth muscle contraction.


Histamine H1 Receptor Engagement

The drug also exhibits antihistamine properties by engaging and antagonizing the Histamine H1 receptor. By blocking this receptor, Frego modifies a key signaling pathway. This antagonism results in the modulation of mediator signaling.


Dopamine D2 Receptor Antagonism

Frego possesses a minor role as an antagonist at the dopamine D2 receptor. This engagement with the central nervous system's signaling pathways influences mechanisms that regulate overactive or dysregulated processes. This modulatory effect influences signaling within central neurological systems.

Dosage and Administration Information

How to Use Frego

Frego (Flunarizine) administration is governed by specific guidelines that define the route, schedule, and duration of use. The medication is delivered in tablet or capsule form and is consistently intended for oral ingestion.

Dosing Schedule and Timing

Administration is structured around a once-daily pattern, and the dose must be taken at night or before going to bed. The standard initial daily dose for adults under 65 is 10 mg, while older adults (age 65 and above) and pediatric patients typically begin with a lower dose of 5 mg daily.

Administration Pattern Detail
Route Oral (tablet or capsule)
Timing Once daily, at night
Adult Initial Dose 10 mg (Adults < 65) or 5 mg (Adults ≥ 65)

Duration and Maintenance

Treatment begins with a time-bound trial period, usually lasting one to two months, to determine the patient's response. If no significant improvement is observed after this initial period, the administration protocol indicates that use should be discontinued.

For continuous administration, the maintenance phase follows a specific intermittent schedule where the daily dose is taken for five consecutive days, followed by two drug-free days each week. This structured, cyclic approach guides the long-term use of the medication.

Use in Specific Populations

Specific dosage rules are in place for certain groups. Individuals 65 years and older are typically started on the reduced daily dose of 5 mg. Due to its primary metabolism in the liver, the use of Flunarizine requires caution in patients with hepatic impairment, though specific dose adjustments are not universally mandated.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Frego (Flunarizine)

This section provides a factual overview of the clinical research for Flunarizine, based on official regulatory documentation and peer-reviewed scientific literature. This information describes what has been studied and what patterns have been observed, and should not be used as clinical advice or personal prediction.


Evidence for use in research efforts for recurrent migraine attacks

Research exploring Flunarizine in studies exploring recurrent migraine attacks includes Randomized Controlled Trials (RCTs) and comprehensive meta-analyses that consolidate findings from many smaller studies. This body of evidence was evaluated in research exploring conditions characterized by fluctuating or episodic manifestations, particularly the frequency and severity of migraine attacks.

In these trials, researchers primarily monitored outcomes describing episodic or acute changes, such as measurements related to changes in the number of monthly migraine days and the percentage of patients who experienced a pre-defined change. The systematic reviews described a pattern of findings related to metrics of headache frequency change across many of the included trials. The populations observed were typically non-elderly adults.


Evidence for use in research exploring chronic dizziness and vestibular disorders

The research for Flunarizine in conditions associated with acute or disruptive episodes of dizziness or balance issues, including recurrent vertigo, has been explored through a mix of clinical trials and systematic reviews. This evidence was evaluated in studies examining patient-reported experiences related to systemic or functional imbalance. Researchers monitored outcomes such as patient-reported outcomes describing perceived discomfort and the severity of dizziness.

The Study Landscape for Vestibular Migraine

For the specific condition known as Vestibular Migraine, studies explored short-term symptom changes in patients experiencing these attacks. Research focused on episodes where symptoms become more noticeable, measuring the change in the number of dizzy spells and the impact on outcomes reflecting daily functioning or activity level. Evidence so far indicates patterns observed in these studies, but the overall certainty remains low.


What is Still Uncertain About the Research for Frego

Evidence quality varies across studies, particularly for older trials that may not adhere to modern research standards. Sample sizes were modest in many of the key studies, and comparative evidence is lacking for many potential active treatments. Furthermore, the overall data for certain groups, such as long-term users, remain insufficient. Research does not determine individual patient outcomes.

Key Studies & References

  1. National Institutes of Health MeSH Overview: Flunarizine

Frequently Asked Questions (FAQ)

Common questions about Frego (FAQ)


Q: What should I do if I accidentally miss a dose of Frego?

Regulatory guidance suggests that if a dose is missed, taking it as soon as it is noticed may be appropriate. However, if the time for the next scheduled dose is near, skipping the missed dose and continuing the regular schedule is the advised action. To maintain safety, taking a double dose to make up for a missed dose is not recommended.


Q: Can I stop taking Frego suddenly, or does it require tapering?

Regulatory documents indicate that the official protocol suggests that discontinuation of the medication may occur if no significant improvement is observed by a healthcare provider after the initial trial period, typically one to two months. If treatment is successful, the maintenance phase may also be stopped after six months. While the prescribing information outlines when to stop the medication, it does not always explicitly detail a specific tapering schedule for all situations.


Q: How long does Frego stay in your system after you stop taking it?

According to the drug’s pharmacological profile, Frego (flunarizine) has a long and variable terminal elimination half-life. The half-life typically ranges from several days to over two weeks, particularly after long-term use. This indicates that measurable amounts of the substance can remain in the body for an extended period following the final dose.


Q: Do I need to take Frego with food, or can I take it on an empty stomach?

Official product information suggests that Frego may be taken either with food or on an empty stomach. Regardless of the timing relative to food, the medication is intended to be swallowed whole with fluid.


Q: Are there any specific foods that should be avoided while on Frego?

Regulatory information explicitly warns against the consumption of alcohol while taking Frego. This restriction is imposed due to the potential for the two substances to cause excessive sedation. No specific non-alcoholic food items are listed as formal contraindications in the official documentation.


Q: Can Frego affect the efficacy of birth control pills?

Official regulatory documents indicate that Frego may reduce the effectiveness of oral hormonal contraceptives, particularly when treatment is first started or if the dose is changed. The use of alternative contraceptive measures, such as a barrier method, may be discussed during these periods.


Q: What are some signs that Frego might not be working for me?

Official prescribing information indicates that if a patient’s condition does not show significant improvement after the initial trial period (typically 1–2 months), the medication's use is often re-evaluated or discontinued by a healthcare professional. Lack of a positive change during this period is the formal, regulatory marker of non-response.


Q: Are there any specific lab tests required before starting Frego?

While the medication is primarily processed by the liver, and its use is contraindicated in severe liver impairment, official prescribing information does not universally mandate specific routine baseline lab tests for all patients. Since the medication is primarily processed by the liver, its use requires caution in patients with existing hepatic impairment.


Q: What are the signs of a serious allergic reaction to Frego?

The official label notes that Frego is formally contraindicated in patients with a known hypersensitivity to the drug or any of its components. Hypersensitivity is a contraindication for using Frego and signs of an allergic reaction are a serious safety concern.


Q: What percentage of people experience common side effects from Frego?

The official product information categorizes side effects by their frequency using standard regulatory definitions, such as Very Common or Common. The frequency categories are based on the standard definitions used by regulatory bodies. Specific, exact percentage data for all listed side effects are generally not included in the official patient summary.


Q: Are there any known drug interactions between Frego and common cold/flu medications?

Regulatory documents warn that combining Frego with substances that act as CNS depressants (central nervous system depressants), which can include some common cold and flu relief medications, carries the potential for enhanced sedation. This combined effect may increase drowsiness.


Q: What are the differences between the various strengths of Frego tablets?

Frego is typically available in two different strengths: 5 mg and 10 mg tablets or capsules. The use of these different strengths is intended to allow for flexibility in treatment protocols, including guiding initial treatment and maintenance schedules.


Q: What makes Frego different from similar medications I've heard of?

Frego is primarily classified as a selective calcium channel blocker (CCB). However, official drug information also highlights its secondary actions, which include acting as an antagonist (blocker) at both the Histamine H1 receptor and the Dopamine D2 receptor. This triple mechanism of action gives the medication a distinctive pharmacological profile.


Q: Does Frego interact with common over-the-counter pain relievers?

The official product information explicitly lists interactions with anti-epileptic drugs, CNS depressants, and anti-hypertensive drugs. Common over-the-counter pain relievers are not specifically named as explicit interacting agents in the regulatory documents.


Q: Is it safe to take Frego while also taking my daily vitamins?

Regulatory documents detail interactions with specific drug categories like CNS depressants and anti-epileptic drugs. General daily vitamins and mineral supplements are not explicitly listed in the official interaction profile.

How should Frego be stored and disposed of?

Frego (Flunarizine) must be stored under specific regulatory conditions to maintain stability and effectiveness. The medicine must be stored at room temperature, which means at a temperature not exceeding 30°C.


Storage Requirements

Condition Requirement
Temperature Do not freeze; store below 30°C.
Protection Protect from light and moisture; keep container tightly closed.
Child Safety Keep out of reach of children.

Disposal Instructions

Unused or expired Frego should be disposed of via an authorized drug take-back program. If one is unavailable, remove the tablets/capsules from their original container, mix them with an undesirable substance like used coffee grounds, and place the mixture in a sealed bag or container before discarding it in the household trash. Do not flush the medication down the toilet unless specifically instructed by official labeling.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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