Amatol

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Amatol

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Medically reviewed

Marina Burgos

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 Amatol

Quick Facts

Property Description
Active ingredient Mebendazole
Form Oral tablet, Oral suspension
Pharmacological class Benzimidazole Anthelmintic
General purpose Eliminates intestinal parasitic worms
Origin Synthetic organic compound

What is Amatol? Defining the Anthelmintic Class

Amatol is a specific trade name for a medication whose active ingredient is Mebendazole, a drug universally recognized for combating parasitic infections. Mebendazole is officially categorized as an anthelmintic agent and belongs to the benzimidazole derivative pharmacological class. This classification places it within a chemically distinct group of compounds supported by pharmacological studies for their efficacy against internal parasites.

This medication is typically intended for use in both adults and children, providing a broad therapeutic reach against various helminth infestations. Mebendazole is a synthetic organic compound, which is a type of medicine often classified as prescription-only in many major jurisdictions. Mebendazole is a medication for treating infections caused by various helminths, representing a critical public health resource.


Composition, Forms, and General Purpose

The foundation of Amatol is the active component, Mebendazole, which is formulated for effective oral administration. The drug is distinguished by being offered in multiple dosage form(s) designed to simplify ingestion, commonly including the chewable tablet alongside the traditional oral tablet and the oral suspension (liquid form).

The final formulation is a single-ingredient product, combining the active drug with either solid excipients (for tablets) or an aqueous vehicle (for suspensions). The medication's general purpose is to provide control over parasitic organisms in a scenario such as a confirmed diagnosis of pinworm or roundworm infection. By targeting and eliminating the parasites, it addresses the root cause of the infestation.

What side effects are possible with Amatol?

Possible Side Effects and Safety Information

The official safety documentation for Amatol (Amobarbital) outlines the documented adverse reactions and necessary safety restrictions, focusing heavily on its effects on the central nervous and respiratory systems.

Commonly Documented Adverse Reactions

Adverse reactions classified as Common (with an estimated incidence of 1–3%) in regulatory labeling primarily involve the nervous system, such as somnolence (drowsiness). Reactions categorized as Less than Common (occurring in less than 1% of patients) span multiple system-organ classes, including agitation, confusion, ataxia, nausea, vomiting, constipation, and various skin rashes.

Serious Adverse Reactions and Constraints

The most significant risks documented in the regulatory profile include respiratory depression, apnea, and laryngospasm (airway closure). The medication is formally contraindicated in patients with marked hepatic impairment (severe liver function issues), certain respiratory diseases, and a history of porphyria. Furthermore, the drug is classified as habit forming due to its potential for developing psychological and physical dependence with continued use.

Duration-Related and Population-Specific Safety

Official labeling warns that prolonged exposure can lead to the development of tolerance and dependence, resulting in severe, potentially fatal withdrawal symptoms if the medication is stopped abruptly. Specific constraints exist for certain populations, including documented risks of fetal damage and neonatal withdrawal syndrome if used during pregnancy, and the potential for paradoxical excitement in patients with pain.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdosage with Amatol (amobarbital) constitutes a life-threatening medical emergency due to its classification as a barbiturate. Officially documented manifestations of overdose primarily involve profound central nervous system (CNS) and respiratory depression. Symptoms may progress from severe drowsiness, sluggishness, and confusion to deep coma, accompanied by neurological signs like slurred speech and loss of reflexes.

Physiological signs listed in regulatory information include critical respiratory depression, apnea (cessation of breathing), and vasodilation which leads to severe hypotension (a dangerous drop in blood pressure). The most serious documented outcomes are death, secondary complications such as pneumonia from aspiration, and potential permanent kidney injury.

Governmental guidance mandates that individuals seek immediate medical attention by calling emergency services (such as 911 or a local poison control center) if an overdose is suspected, especially if the patient exhibits breathing problems or seems extremely tired. Management is strictly supportive, as no specific antidote is known for barbiturate toxicity. Interventions officially described involve maintaining the patient's airway, providing mechanical ventilation, and using procedures like activated charcoal under intensive hospital monitoring.

Therapeutic Uses of Amatol

Quick Facts

  • May be administered for short-term management of insomnia.
  • Used to support sedation before a procedure (preanesthetic).
  • Has been used in the acute management of refractory tonic-clonic seizures.

Amatol (amobarbital) is a compound that acts on the central nervous system. In supervised clinical settings, it may be used to address specific medical conditions. The therapeutic applications primarily focus on its sedative and hypnotic properties.

Historically, Amatol has been administered for the short-term management of insomnia, which relates to its ability to support the induction of sleep. It may also be used to promote sedation as part of preanesthetic care before surgical procedures. Additionally, the compound has seen use in the acute management of certain types of seizures, including refractory tonic-clonic episodes.

Due to its potential for tolerance and dependence, its current use is typically limited to clinical settings and short durations. Usage must always be determined by a qualified healthcare professional, who will assess the individual patient's condition and needs.

Regulatory References

  1. NIH MedlinePlus guidance

Eligibility and Restrictions for Use

Eligibility Map: Who can and cannot use Amatol

Official regulatory documents strictly define the populations that may or may not use this medicine (Amobarbital/Amatol).

Eligibility Scope Official Regulatory Status
Populations for whom use is contraindicated Patients with a history of manifest or latent porphyria. Patients with marked impairment of liver function or severe respiratory disease where obstruction is evident. Patients with hypersensitivity to barbiturates or any formulation component.
Age-related eligibility rules Safety and effectiveness are not established in children under 6 years of age. Use in older adults (geriatric) is generally avoided due to heightened risk of CNS effects, dependence, and potential for overdose.
Condition-specific eligibility rules Use requires caution in patients with renal impairment, acute or chronic pain, or a history of drug or alcohol use disorder. Contraindicated in marked impairment of liver function.
Pregnancy and lactation eligibility status Pregnancy: Barbiturates are associated with the risk of fetal damage, and withdrawal symptoms may occur in infants. Use is generally avoided. Lactation: Caution is recommended as the drug is excreted into human milk.

Official Eligibility Classifications

The regulatory profile mandates Absolute Contraindication for specific metabolic and organ conditions. It is classified as a DEA Schedule II controlled substance, which denotes a high potential for abuse and severe physical or psychological dependence, further restricting its use to defined clinical circumstances.

What should I know about interactions with other medicines?

Documented Interaction Profile

The official regulatory documentation for Amatol establishes specific interaction patterns based on metabolic and pharmacodynamic mechanisms.

Metabolic and Exposure Alterations

Amatol is a known inducer of hepatic microsomal enzymes. This interaction increases the metabolic clearance of several co-administered medicinal products, which can lead to reduced plasma concentrations and diminished therapeutic effects. This exposure-reducing effect has been officially documented for Oral Contraceptives, Corticosteroids, and the anticoagulant Warfarin. Conversely, co-administration with substances that inhibit Amatol’s own metabolism, such as Valproic Acid or Monoamine Oxidase Inhibitors (MAOIs), results in increased plasma exposure and prolonged effects of Amatol. Co-use with MAOIs is therefore subject to official restriction.

Pharmacodynamic and Substance Interactions

A primary pharmacodynamic interaction involves combining Amatol with other Central Nervous System (CNS) depressants, including Opioid Analgesics and Sedating Antihistamines. This co-administration produces a notable additive CNS depressant effect. Similarly, the consumption of Ethanol (Alcohol) results in an enhanced depressant effect.

Population Considerations

Official labeling notes that patients with hepatic impairment may experience reduced clearance of Amatol, which can potentiate the effects of co-administered CNS depressants. Elderly or debilitated patients are also cited as being more susceptible to these additive CNS effects.

Mechanism of Action

How Amatol Works

The mechanism of Mebendazole (Amatol) is characterized by highly selective toxicity, primarily targeting the internal functions of the parasite, initiating a critical energy deficit. This action unfolds through a precise molecular sequence.


Molecular Targeting of Helminth beta-Tubulin

The drug's initial action is a specific inhibitor function, engaging the beta-tubulin component within the parasite's cells. This target is essential for assembling microtubules, which are vital for internal structure and transport. Mebendazole preferentially binds to the helminth's tubulin rather than the host's, allowing the mechanism to proceed.


Cascade of Nutrient Starvation and Energy Failure

The loss of microtubules halts the intracellular transport of essential proteins, blocking the parasite’s ability to absorb glucose and nutrients from the host's gastrointestinal lumen. This rapid nutrient blockade initiates a mechanistic cascade leading to the complete depletion of glycogen reserves and a critical drop in ATP (cellular energy).


Resulting Physiological Effect: Paralysis and Expulsion

The sustained energy crisis and cellular degeneration lead directly to the paralysis of the parasite's musculature. This physiological consequence results in the immobilized and debilitated organism becoming functionally impaired. The reliance on energy depletion dictates a gradual progression of the mechanism's physiological consequences.

Dosage and Administration Information

The administration of Amatol (Mebendazole) is strictly limited to the oral route, defining its use as a short-course treatment for intestinal helminth infections. The medication is typically available as a chewable tablet and an oral suspension, allowing for flexibility in administration. Tablets may be chewed, swallowed whole, or crushed and mixed with food, simplifying intake for various patient needs. No special pre-treatment procedures, such as fasting or purging, are required prior to administration.

The dosing structure is standardized and dependent on the specific infection being addressed. For pinworm infection, the standard regimen is a single 100 mg dose. For infections caused by whipworm, roundworm, or hookworm, the labeled dose is 100 mg twice daily (BID), taken morning and evening, for a fixed duration of three consecutive days.

The standard adult dosage schedule applies consistently to pediatric patients aged two years and older for intestinal infections. The medication may be taken with or without food; however, concurrent administration with a fatty meal may lead to increased systemic absorption. If a dose is missed, the general practice is to take it as soon as it is remembered, unless the next dose is due shortly. If a cure is not achieved within three weeks of the initial course, a second full course of treatment may be utilized.

Recent Clinical Evidence

Evidence for Short-Term Management of Insomnia

Research for managing temporary sleep difficulties largely consists of historical, short-term controlled trials. These studies, typically limited to adult populations, evaluated outcomes such as the time taken to fall asleep (sleep latency) and the total duration of sleep. Studies were used to evaluate whether participants reported a difference in these metrics compared to an inactive substance. However, the evidence is limited by the short follow-up duration (often le two weeks) and the lack of contemporary comparative data.


Evidence for Preanesthetic Sedation

The research base for promoting calm before medical procedures is primarily derived from observational clinical reports and expert data, rather than recent, controlled trials. Studies monitored sedation level and patient apprehension in both adult and pediatric populations. Findings describe patterns related to achieving sedation outcomes, but modern practice often relies on other compounds. Dedicated clinical data for pediatric populations and recent comparative evidence are lacking.


Evidence for Acute Management of Refractory Seizures

Amatol was studied for its role in managing severe, acute seizure episodes that did not respond to initial treatments. Evidence is based on case series and retrospective observational studies of critically ill patients (adults and children). These studies monitored metrics related to seizure activity and the time intervals required to reach a stable state. The compound is used in specific contexts, often where it is considered after initial treatments. Research is limited by small, non-randomized samples, reflecting its use only in refractory cases.


Long-Term Studies and Follow-Up Duration

Across all indications, the evidence is constrained by short-term outcomes and acute management focus. Follow-up durations are limited to a few weeks for insomnia and hours to days for acute conditions. Long-term effects, tolerance development, and durability of response are not fully established by the existing research base.


Evidence in Special Populations and Uncertainty

Research was evaluated in studies including adults and children, but dedicated data for pediatric groups and patients with specific comorbid conditions are not fully established. Overall, the evidence base is historical, comparative evidence is lacking against modern options, and certainty remains low due to limited follow-up and sample sizes.

Key Studies & References Amobarbital Sodium Injection Drug Label: Indications and Usage

Frequently Asked Questions (FAQ)

Common questions about Amatol (FAQ)

Q: How is the action of Amatol described in patient-friendly terms?

In simple terms, the medication works by preventing the targeted parasite from absorbing essential nutrients, primarily glucose (sugar). This action leads to a critical loss of energy that causes the elimination of the organism.

Q: How long does it typically take to feel the general effects of Amatol?

For the oral form of this medication, official prescribing information describes the onset of its sedative and hypnotic action as typically starting within approximately 45 minutes to 1 hour after administration. This time frame is the documented onset for the medication's action.

Q: Is it common to feel tired or fatigued when first starting Amatol?

Official safety documentation indicates that somnolence, which is the medical term for drowsiness, is one of the most commonly reported adverse reactions. The incidence of this effect is officially estimated at 1–10%.

Q: Are there any documented severe side effects associated with Amatol?

Yes, documented serious risks include severe reactions such as respiratory depression (slowed or shallow breathing), temporary cessation of breathing (apnea), and laryngospasm (airway closure).

Q: Does Amatol have any documented interaction with common over-the-counter pain relievers?

Official documents note that the co-administration of this medication with common pain relievers like acetaminophen may alter its effects. This combination may potentially result in liver-related side effects.

Q: Is Amatol generally used in older adults, according to official information?

According to established prescribing guidelines, the use of this medication in older adults (geriatric patients) is generally avoided. This is a caution based on documented risks such as heightened CNS effects, dependence, and potential for overdose in this population.

Q: Do people with kidney issues have specific cautions or contraindications listed for Amatol?

Official documents state that the use of this medication requires caution in patients with known renal impairment (kidney issues).

Q: Does Amatol require regular blood tests or medical monitoring generally?

Regulatory labeling mentions that laboratory tests and blood counts may be monitored in certain clinical contexts. This monitoring is typically used in specific situations, such as prolonged therapy or for certain underlying conditions.

Q: How is the risk of an allergic reaction to Amatol described in regulatory documents?

Official product information states that the drug must not be used in patients with a history of hypersensitivity to barbiturates or any of its components. Additionally, hypersensitivity reactions, including swelling under the skin (angioedema), have been reported as adverse events.

Q: Does Amatol carry a specific regulatory boxed warning or classification?

Official regulatory documents classify this medication as a DEA Schedule II controlled substance. This classification indicates a high potential for abuse and severe physical or psychological dependence.

Q: Do the side effects of Amatol typically decrease or go away over time?

Product information suggests that for certain common effects, such as gastrointestinal discomfort and headache, the symptoms are typically transient. These effects often resolve as the body adjusts to the medication.

Q: Can Amatol be stopped suddenly without issues, based on product information?

Official warnings state that abrupt cessation of the drug after prolonged use in a dependent person may result in serious withdrawal symptoms. These symptoms can include delirium and convulsions.

Q: Are there common foods or beverages that official warnings mention may interact with Amatol?

Official documentation specifically notes that co-use with Ethanol (alcohol) can produce additive central nervous system (CNS) depressant effects.

Q: Does Amatol affect a person's general ability to drive or operate machinery?

Due to the documented risk of dizziness and drowsiness, product warnings state that activities requiring mental alertness should be approached cautiously. For these reasons, the manufacturer recommends exercising caution.

Q: What is the typical duration of action listed for a single dose of Amatol?

The oral form of this medication is categorized as an intermediate-acting barbiturate. Regulatory documents list its typical duration of action for a single dose as ranging from 6 to 8 hours.

Q: Does Amatol interact with common herbal supplements like St. John's Wort?

Official interaction information states that combining this medication with the herbal supplement St. John's Wort may increase the risk or severity of central nervous system (CNS) depression.

Q: Is it true that Amatol can cause trouble sleeping or insomnia?

While the medication is used for sedation, regulatory adverse event reports include insomnia (trouble sleeping) as a possible, albeit less frequently reported, side effect.

Q: What does it mean for Amatol to be 'indicated' for a specific condition?

A drug's indication means that the manufacturer has submitted evidence of its safety and effectiveness for that specific condition. The regulatory authority has subsequently determined its safety and effectiveness for that use.

Q: Can Amatol be taken with common over-the-counter cold and flu medicines?

Warnings highlight the documented risk that combining this medication with other Central Nervous System (CNS) depressants, often found in cold and flu medicines, could result in an enhanced depressant effect.

Q: Are there any documented side effects related to weight changes from Amatol?

Adverse event reports associated with the active ingredient have included instances of weight loss. However, the frequency of weight change is generally not consistently established across all official product documentation.

Q: Is Amatol considered a relatively new or established medication?

The nature of the evidence base, which includes historical studies and expert data, indicates that the medication is an established presence in clinical use.

Q: Does the official labeling mention specific lifestyle changes while using Amatol?

For the specific treatment of intestinal infections, official guidance includes information on specific hygiene and cleaning measures. This includes actions like thorough hand washing and cleaning bedding to help prevent reinfection.

Q: Why is Amatol sometimes described as an 'adjunctive' treatment?

The term indicates that the drug is used in addition to a primary or other therapy in specific clinical situations, such as when describing its role in the postoperative surgical period.

Q: Does Amatol cause any change in appetite?

Adverse event reports associated with the drug's active ingredient have included instances of loss of appetite. This information is based on patient reports, and the frequency of this change is not consistently established in the documentation.

Q: Is Amatol described as having any risk of dependency or withdrawal symptoms?

Yes, the medication is classified as habit forming due to the potential for developing psychological and physical dependence with continued use. Official warnings detail the potential for severe withdrawal symptoms if the drug is stopped abruptly.

Q: Are there specific warnings about Amatol use during pregnancy or breastfeeding?

Official warnings cite the risk of fetal damage if the medication is used during pregnancy, and infants may experience withdrawal symptoms after birth. Caution is also advised during breastfeeding because the drug is excreted into human milk.

Q: What do studies say about the long-term effectiveness of Amatol?

Across all approved indications, the official research base is generally constrained by its focus on short-term outcomes. Information on long-term effects, tolerance development, and durability of response is not fully established by the existing studies.

Q: What are the key points to know about the safety profile of Amatol?

The safety profile highlights the classification as a Schedule II controlled substance due to its potential for abuse and dependence. Key contraindications are for patients with marked liver impairment or severe respiratory disease.

How should Amatol be stored and disposed of?

How to Store and Dispose of Amatol (Amobarbital)

The official storage and disposal requirements for Amatol (Amobarbital) are defined by regulatory agencies to maintain product stability and ensure public safety.


Official Storage Requirements

  • Temperature: Store the product at Controlled Room Temperature, typically ranging from 15 C to 30 C (59 F to 86 F).
  • Protection: The medication must be kept in its original, tightly closed container and protected from light and moisture.
  • Child Safety: It is mandatory to store the product out of the sight and reach of children.
  • Stability: For the injectable form, the reconstituted solution must be used within 30 minutes of preparation.

Official Disposal Instructions

  • Method: Due to its classification as a controlled substance, disposal should be managed through an official drug take-back program.
  • Restriction: If a take-back program is unavailable, the medication must be mixed with an unpalatable substance (like dirt) and sealed in a bag for disposal in household trash; do not flush it down the toilet or pour it down a drain.

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

Equivalent of Amatol found in:

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