Gammexane

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Gammexane

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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 Gammexane

Gammexane is a trade name for a medicine containing the active substance Lindane, which is a highly potent agent classified as an ectoparasiticide. Its primary function is the control and elimination of ectoparasites, such as mites and lice, that infest the skin or hair.

Property Description
Active ingredient Lindane (gamma-Hexachlorocyclohexane)
Form Topical preparations (Lotion, Cream, Shampoo)
Pharmacological class Ectoparasiticide, Scabicide
General purpose Clearance of external parasitic infestations
Origin Synthetic organochlorine compound

Gammexane: Active Ingredient and Pharmacological Classification

The core chemical entity in Gammexane is Lindane, a highly purified version of the synthetic compound gamma-hexachlorocyclohexane. It is clinically recognized for its potent parasiticidal action. Due to its neurotoxic properties directed specifically at pests, it is formally classified as an ectoparasiticide and scabicide. This classification confirms the drug's therapeutic purpose is limited to addressing parasitic skin conditions. Several other trade names, such as Kwell and Scabene, utilize this same formulation, indicating a recognized standard.

Form, Composition, and General Therapeutic Purpose

Lindane is manufactured as a single-ingredient topical preparation, exclusively designed for surface application. It is typically prepared as an aqueous-based lotion, a cream, or a shampoo, suitable for targeted cutaneous delivery to the affected area. The drug works by acting as a neurotoxin to the parasites, causing their nervous systems to become rapidly hyperexcited. This effect is known to be robust against both adult pests and their eggs (ovicide effect), a mechanism essential for achieving complete and lasting clearance of the infestation.

Lindane’s Position as a Restricted Second-Line Agent

As a potent synthetic organochlorine compound, Lindane belongs to a class of chemicals with inherent differences from newer treatments. Due to this potency, the medication is generally reserved as a second-line therapy. Its prescription-only status further distinguishes it, ensuring that its use is restricted to patients who cannot tolerate or have failed to respond to initial, less potent therapeutic options.

What side effects are possible with Gammexane?

Official Safety Profile and Adverse Reactions

The regulatory safety profile for Lindane (Gammexane) is characterized by documented risks of neurotoxicity and specific warnings concerning systemic absorption. This classification necessitates that the medicine be generally reserved as a second-line therapy, as noted in official guidelines.

Serious Adverse Reactions and Neurotoxicity

Regulatory documentation includes the potential for seizures and, in rare instances, death, associated with its use. These serious adverse events are linked to the systemic absorption of the product, which primarily impacts the Nervous System Disorders organ class. These reactions have been reported following both a single proper application and after repeated or prolonged exposure.

Common Adverse Reactions

The most frequently observed adverse reactions are generally dermatological and are classified as common in official documents:

  • Pruritus (itching)
  • Burning skin sensation
  • Dry skin and skin rash (dermatitis)

These effects fall under the Skin and Subcutaneous Tissue Disorders system-organ class. Itching, which is a symptom of the underlying condition, may persist for one to several weeks following successful treatment, as documented in the label.

Population-Specific Safety Considerations

Official labeling identifies specific populations at greater risk of serious neurotoxicity and resultant adverse events. This increased risk is noted for infants, children, the elderly, and individuals whose body weight is below approximately 50 kilograms (110 lbs). Due to the heightened risk of absorption, the medication is contraindicated in premature neonates and those with existing conditions that increase systemic absorption, such as Crusted (Norwegian) Scabies or extensive inflammatory skin disorders.

Overdose and Emergency Response

Overdose Manifestations and Severity

Overexposure to Gammexane (Lindane) is officially documented in regulatory sources as primarily presenting with signs of neurotoxicity. The clinical manifestations associated with overdose may include seizures (convulsions), uncontrolled body shaking, confusion, dizziness, and headache. The most severe, life-threatening outcomes formally listed in official labeling include grand mal seizures, coma, and death, establishing the need for immediate intervention. Systemic complications such as cardiac arrhythmias and pulmonary edema are also cited in the official profile.

Mandated Emergency Actions

Immediate medical attention is required upon the onset of any severe symptoms. The official regulatory instruction is to call emergency services (911) immediately if the individual collapses, has a seizure, has trouble breathing, or cannot be awakened. If the product is accidentally swallowed or gets into the mouth, the Poison Control Center must be contacted right away. Management is restricted to symptomatic and supportive care, as officially documented in prescribing information.

Risk Considerations

The risk of severe neurotoxicity is heightened in specific populations identified in official labeling, including infants, children, elderly persons, and individuals weighing less than 50 kg (110 lbs). Patients with a history of seizure disorders, head trauma, CNS tumors, or severe hepatic cirrhosis are also noted as being at a heightened risk for systemic toxicity following exposure. The official overdose profile strictly defines the high risk of systemic toxicity and mandates urgent, specific actions based on the presentation of neurological symptoms.

Therapeutic Uses of Gammexane

Gammexane (Lindane) is an agent applied across domains where additional symptomatic support is needed for specific parasitic skin conditions. Its therapeutic application is generally used in situations where initial, less potent treatments have failed to achieve clearance or when they cannot be tolerated.

Management of Persistent Parasitic Organisms

The medication's primary use is applied in addressing the infestation in its various stages, which supports the overall management of the condition in conditions where symptoms may intensify temporarily or become persistent. Its primary indications include managing infestations of scabies and pediculosis (head lice, body lice, and pubic lice).

Support in Addressing Symptoms Related to Physical Discomfort

By helping to eliminate the parasitic source, Gammexane is applied in addressing symptom clusters related to physical discomfort, specifically the pruritus (itching) that interferes with daily functioning and associated skin irritation. This action contributes to easing the overall symptom load, and supports the patient during difficult episodes by easing distress.


Quick Fact: Relief for Pruritus Gammexane helps resolve the underlying cause of symptoms related to physical discomfort, providing supportive relief in contexts involving heightened systemic burden where pruritus (itching) that creates noticeable physiological strain significantly interferes with comfort and sleep.

Regulatory References

  1. NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

The eligibility for Gammexane (Lindane) is heavily restricted by regulatory agencies, classifying it as a second-line treatment reserved for individuals who cannot tolerate or have failed safer, initial therapies. These restrictions are based on the risk of serious systemic neurotoxicity, including seizures.

Eligibility Scope

Classification Population/Condition
Absolutely Contraindicated Premature infants; individuals with known uncontrolled seizure disorders; patients with crusted (Norwegian) scabies; patients with damaged, broken, or inflamed skin.
Conditional/Restricted Use Infants, children, the elderly, and individuals weighing less than 110 pounds (50 kg).

Eligibility-Related Restrictions

Lindane is contraindicated in any person with a known hypersensitivity to the drug or its components. Use is highly restricted in patients with conditions that increase the risk of seizures, such as HIV infection, a history of head trauma, or severe hepatic cirrhosis. For pregnant individuals, use is avoided unless necessary. Regulators advise that breastfeeding mothers should interrupt nursing for at least 24 hours following application.

What should I know about interactions with other medicines?

Gammexane Interactions with other medicines and products

The official interaction profile for Gammexane (Lindane) is defined by two primary documented risks: Pharmacodynamic Reinforcement of Neurotoxicity and Systemic Exposure Enhancement, as outlined in regulatory documents.

Interacting Medicinal Products and Substances

Co-administration with medicinal products known to lower the seizure threshold may result in an additive neurotoxic effect. This pharmacodynamic risk involves numerous drug classes, including antipsychotics, antidepressants, quinolone antibiotics, theophylline, and certain immunosuppressants. The prescribing information explicitly cites specific agents, including Isoniazid, Imipenem, and Centrally Active Anticholinesterases, as posing this risk. Furthermore, the use of oil-based hair dressings, creams, or ointments is documented to enhance the systemic absorption of Lindane through the skin, increasing the potential for adverse neurological outcomes.

Interaction-Related Restrictions and Constraints

Regulatory documents impose specific restrictions based on interaction risk. The product is prohibited (contraindicated) in patients with uncontrolled seizure disorders or conditions like crusted (Norwegian) scabies where systemic absorption is significantly enhanced. To mitigate the risk of enhanced exposure, a timing-based administration restriction requires that topical oil-based products be avoided immediately before and after application. The risk of a neurotoxic interaction outcome is also formally documented as heightened in specific populations, including patients with severe hepatic cirrhosis, HIV infection, CNS tumor, and in both pediatric and elderly patients.

Mechanism of Action

How Gammexane Works: Mechanism of Action

1. Primary Mechanism: Non-Competitive Neuroreceptor Blockade

Gammexane (Lindane) exerts its mechanism by targeting the GABA A receptor complex, which functions as a GABA-gated chloride ion channel in the nervous system of susceptible arthropods. The molecule acts as a non-competitive antagonist by binding to the picrotoxin site located within the channel pore. This specific molecular interference prevents the normal influx of chloride ions ( Cl^-), which is essential for mediating neuronal inhibition.

2. Mechanistic Cascade and Physiological Effect

By disrupting the flow of chloride ions, Gammexane suppresses the entire GABAergic inhibitory pathway. This loss of inhibition leads directly to a state of neuronal hyperexcitation throughout the central nervous system. The continuous, uncontrolled firing of neurons initiates a cascading overstimulation that results in unchecked motor neuron activation and excessive muscle stimulation. This systemic neurotoxicity culminates in paralysis and motor failure, which are the final physiological consequences of the drug's molecular action.

Dosage and Administration Information

How to Use Gammexane: Official Administration Guidelines

Gammexane (Lindane) is a highly restricted medication with specific administration protocols, designed for a single course of treatment only. The administration method is strictly topical (applied to the skin or hair) using the 1% lotion or 1% shampoo formulations.

Official Dosing and Application Rules

The usage protocol is strictly time-bound and based on a single application only, with re-treatment not being recommended under any circumstances. Dosing recommendations typically follow the regimens outlined below.

Administration Protocol Lotion (Scabies) Shampoo (Lice)
Route of Administration Topical to skin (neck down) Topical to hair/scalp
Dosing Amount 30 mL (1 oz.); max. 60 mL (2 oz.) 30 mL (1 oz.); max. 60 mL (2 oz.)
Contact Duration Leave on for 8 to 12 hours Leave on for exactly 4 minutes
Post-Treatment Wash off thoroughly after contact time Rinse immediately and thoroughly

Administration Conditions and Restrictions

Application Preconditions: Before use, the skin or hair should be clean, dry, and cool. The lotion or shampoo must be applied directly without dilution or mixing. Caregivers administering the product are advised to use protective gloves.

Population Rules: The medication is generally intended for adults and children weighing at least 110 pounds (50 kg). Use in premature infants is specifically contraindicated. It must not be applied to broken skin, open wounds, or severely irritated skin areas. The treated area should not be covered with occlusive or plastic dressings.

Recent Clinical Evidence

Evidence for Use in Scabies Infestation

The clinical research for Lindane was evaluated in Randomized Controlled Trials (RCTs) and comparative studies, where researchers examined responses against other medications used for mite infestations, such as permethrin. These studies included both general adult and pediatric populations, focusing on measuring study endpoints defined as the absence of mites and outcomes related to physical discomfort. Follow-up periods were typically short-term, set at two to four weeks. The evidence base includes data for patient groups where initial treatments were previously studied but not utilized.

Studies reported varying cure rate measurements when Lindane was evaluated against other treatments utilized in the same study design. Research also highlights changes measured during the study period concerning parasite resistance, where observations documented resistance patterns in specific regions where the compound had seen extensive use.

Evidence for Use in Pediculosis (Lice Infestation)

The research landscape for Lindane in addressing pediculosis (lice infestation) was evaluated in RCTs and systematic reviews, where researchers examined patterns against other pediculicides. These studies monitored responses in school-aged children and adults, with primary endpoints measuring the clearance of live lice and the ovicidal effect (killing of the eggs). Follow-up assessments typically occurred at one and two weeks.

Findings in the context of comparative trials were sometimes mixed, with some research describing varying clearance rate patterns for Lindane when compared against alternative agents in treatment-naïve populations.


Study Limitations and Research Gaps

Research provides context but not individual predictions, and the certainty of long-term effects is not fully established. The duration and maintenance of clinical clearance in the long term (beyond one month) are not extensively characterized in existing randomized studies. Similarly, research exploring outcomes in infants (under two years of age) is limited, and the overall evidence base for pubic lice is smaller compared to the research available for head lice. These limitations, coupled with documented resistance patterns, highlight areas where further research is needed.

Frequently Asked Questions (FAQ)

Common questions about Gammexane (FAQ)

Q: How quickly does Gammexane usually start working for the intended purpose?

A: Gammexane is administered as a single application intended to address the infestation. However, official information suggests that itching, which is a symptom of the underlying condition, may persist for one to several weeks even after successful treatment has cleared the parasites.


Q: Are there any common over-the-counter supplements that can interact with Gammexane?

A: Regulatory information indicates that a healthcare provider should be informed about all medicines, including prescription and non-prescription products, vitamins, nutritional supplements, and herbal products. This precaution is taken because certain supplements may increase the risk of seizures when used alongside Lindane (Gammexane).


Q: How does Gammexane compare to similar-sounding medicines that treat the same thing?

A: Gammexane (Lindane) is officially designated as a second-line treatment by regulatory authorities. This means the medicine is generally reserved for individuals who cannot tolerate or have failed to respond to initial therapies.


Q: Does Gammexane cause drowsiness or affect my ability to drive?

A: Official safety documents indicate that side effects of Lindane may include feeling sleepy or dizzy, as well as having body shaking that cannot be controlled. These are generally categorized as Nervous System Disorders. Regulatory documents note that individuals using the medicine may experience these potential effects.


Q: What should I do if I accidentally get Gammexane in my eye or mouth?

A: According to official product information, if the topical product contacts the eyes, official instructions state they should be rinsed immediately with water. If the product is swallowed, regulatory documents direct users to contact a poison control center immediately and seek emergency medical attention.


Q: Does Gammexane contain any common allergens, like peanut oil or latex?

A: Official medication guides advise checking the list of all inactive ingredients included with the specific Gammexane product. Reviewing this list is important for identifying potential allergens in the preparation.


Q: Are there any specific foods or drinks that should be avoided while using Gammexane?

A: Regulatory sources indicate that patients typically continue their normal diet, unless otherwise advised by a healthcare professional. No specific food restrictions are typically documented for this medication.


Q: Is Gammexane known to affect fertility in men or women?

A: Animal studies have indicated potential reproductive effects, such as changes to sperm count or ovarian cycling, with high-level exposure. Official human data concerning fertility is limited but suggests potential hormonal changes may occur.


Q: What are the long-term safety data themes for Gammexane use?

A: Due to its classification as a potent synthetic organochlorine compound, regulatory reports indicate that chronic exposure to Lindane has been associated with effects on the liver, blood, and nervous system in occupational settings. The duration and maintenance of clinical clearance in the long term (beyond one month) are not extensively characterized in existing randomized studies.


Q: Does Gammexane interact with alcohol?

A: Official documents cite heavy alcohol drinking as a pre-existing condition that could increase the chances of getting a seizure when using Lindane. This risk is related to the drug's effect on the nervous system.


Q: Is it safe to use Gammexane if I have kidney or liver problems?

A: Regulatory documents list a history of severe cirrhosis of the liver as a risk factor that may increase the chances of getting a seizure and is a condition that often restricts use. Animal studies also note potential effects on the kidneys.


Q: What is the physical appearance of Gammexane (color, texture, form)?

A: The active substance Lindane is described as a colorless or white, crystalline solid in its pure, isolated form. The final product is prepared as an aqueous-based topical lotion, cream, or shampoo.


Q: How long after stopping Gammexane does it stay in the body?

A: The active substance is systemically absorbed into the body after dermal application. Studies have measured the highest concentration in the body in the hours following use, and it is eliminated, though trace amounts may persist.


Q: Can people with certain chronic diseases use Gammexane?

A: Regulatory information indicates that those with chronic conditions like HIV or AIDS or a history of problems that could increase the chance of seizure, such as previous head injury or a CNS tumor, should inform their doctor before use.


Q: Is the benefit of Gammexane supported by Level 1 evidence?

A: Official documents confirm that the medicine's use was evaluated in Randomized Controlled Trials (RCTs) and systematic reviews. These are recognized sources of high-level evidence used to establish the benefit of the medicine.


Q: Are there specific instructions for what to do if an allergic reaction is suspected?

A: The official labeling emphasizes that users should seek immediate emergency help if a seizure occurs while the product is being used. This guidance is provided due to the risk of serious adverse neurotoxic events.


Q: Does Gammexane affect mood or mental health?

A: The regulatory safety profile is primarily focused on the risk of severe neurotoxicity that can lead to seizures and death. There is no official information in the label about common mood or mental health side effects such as anxiety or depression.


Q: What are the key findings from recent clinical studies on Gammexane?

A: Clinical studies have documented varying cure rate measurements when the drug was evaluated against other treatments for parasitic infestations. Official research also highlights observations of parasite resistance patterns in specific regions where the compound has seen extensive use.

How should Gammexane be stored and disposed of?

Official Storage and Disposal Requirements for Gammexane (Lindane)

Requirement Type Official Regulatory Condition
Temperature Store at controlled room temperature, 15 to 30 C (59 to 86 F).
Environmental Protection Keep the product in its original container, tightly closed. Store away from excess moisture, direct light, and do not allow it to freeze.
Child Safety The medication must be kept strictly out of the sight and reach of children and pets.
Stability/Leftovers Any portion of the lotion or shampoo must be immediately discarded after a single application and should not be saved for subsequent use.
Disposal Disposal should follow local regulations. Do not release the substance into the environment, as it is classified as toxic to aquatic life. Unused product may be disposed of in household trash only after mixing it with an unappealing material, securing it in a sealed bag, and discarding it.

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

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