Usage
Lindane is a prescription medication primarily indicated for the treatment of scabies and lice infestations (head lice and pubic lice, also known as crab lice) in patients who cannot tolerate or have failed first-line treatment with safer medications.
It belongs to the pharmacological classification of ectoparasiticides, specifically, it is an organochlorine insecticide.
Lindane works by disrupting the nervous system of the parasites, leading to their paralysis and death. It also kills the eggs (nits) of lice.
Alternate Names
- Gamma benzene hexachloride (former name)
- Kwell (brand name)
- Thionex (brand name)
- Gamasol (brand name)
- Gamascab (brand name)
How It Works
Pharmacodynamics: Lindane acts on the nervous system of parasites (scabies mites and lice) by interfering with the GABA-gated chloride channels in the nerve cell membrane. This disrupts nerve signaling, leading to convulsions, paralysis, and death of the parasites.
Pharmacokinetics:
- Absorption: Lindane is absorbed slowly and incompletely through intact skin. Absorption is increased if applied to broken, irritated, or inflamed skin.
- Distribution: After absorption, it is distributed throughout the body and can cross the placenta and enter breast milk.
- Metabolism: Lindane is primarily metabolized in the liver.
- Elimination: It is excreted through urine and feces, with an elimination half-life of approximately 18 hours.
Dosage
Standard Dosage
Adults:
Scabies: Apply 30 mL (1 ounce) of lotion thinly to the entire body from the neck down. For larger adults, up to 60 mL (2 ounces) may be necessary. Wash off thoroughly with warm water after 8-12 hours. Apply only once and do not retreat even if itching persists.
Head or Pubic Lice: Apply 30-60 mL (1-2 ounces, not to exceed 2 ounces) of shampoo to dry hair. Leave on for 4 minutes, lather, and rinse thoroughly. Remove nits with a fine-toothed comb. A single application is usually sufficient. If necessary, another pediculicide can be used after one week.
Children:
Lindane use in children should be carefully considered due to the increased risk of neurotoxicity. Dosages are similar to adults but should be adjusted based on body weight and surface area, not exceeding the maximum adult dose. Strict adherence to application instructions and duration of treatment is crucial. Pediatric patients should be closely monitored for signs of toxicity.
Special Cases:
- Elderly Patients: Increased risk of neurotoxicity. Use with caution and consider lower doses.
- Patients with Renal Impairment: Dosage adjustments may not be necessary, but close monitoring is recommended.
- Patients with Hepatic Dysfunction: Use with caution due to impaired metabolism.
- Patients with Comorbid Conditions: Use cautiously in patients with a history of seizures, CNS tumors, HIV/AIDS, head trauma, liver disease, or psoriasis.
Clinical Use Cases
Lindane is not recommended for use in clinical settings like intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations. Safer alternatives are preferred.
Side Effects
Common Side Effects:
- Skin irritation (itching, burning, dryness)
- Rash
- Numbness or tingling of the skin
- Dizziness
- Drowsiness
Rare but Serious Side Effects:
- Seizures
- Aplastic anemia
- Cardiac arrhythmias
- Pulmonary edema
- Hepatitis
Long-Term Effects:
Chronic complications are rare with proper use, as it’s a single application treatment. However, misuse can cause persistent neurologic issues.
Adverse Drug Reactions (ADR):
Contraindications
- Premature infants
- History of uncontrolled seizures
- Crusted (Norwegian) scabies
- Skin conditions that enhance absorption (e.g., atopic dermatitis, psoriasis)
- Hypersensitivity to lindane
Drug Interactions
Lindane can interact with drugs that lower the seizure threshold, including:
- Antipsychotics
- Antidepressants
- Certain antibiotics (e.g., penicillins, imipenem)
- Theophylline
- Isoniazid
- Alcohol
Pregnancy and Breastfeeding
- Pregnancy: Lindane is classified as Pregnancy Category C. It’s not recommended during pregnancy due to potential risks of neural tube defects and developmental problems.
- Breastfeeding: Lindane passes into breast milk. Discontinue breastfeeding for at least 24 hours after application. Pump and discard breast milk during this time.
Drug Profile Summary
- Mechanism of Action: Disrupts parasite nerve function by interfering with GABA-gated chloride channels.
- Side Effects: Skin irritation, rash, dizziness, seizures (rare).
- Contraindications: Premature infants, seizure disorders, crusted scabies.
- Drug Interactions: Drugs lowering seizure threshold (e.g., antipsychotics, antidepressants).
- Pregnancy & Breastfeeding: Not recommended during pregnancy; discontinue breastfeeding for 24 hours after use.
- Dosage: Apply once, wash off after 8-12 hours (lotion) or 4 minutes (shampoo).
- Monitoring Parameters: Observe for signs of CNS toxicity (e.g., dizziness, seizures).
Popular Combinations
Lindane is not typically used in combination with other drugs for scabies or lice treatment.
Precautions
- Avoid contact with eyes, nose, and mouth.
- Do not use on open wounds or irritated skin.
- Use with caution in children, the elderly, and individuals weighing less than 50 kg.
- Avoid retreatment.
- If applying to others, wear nitrile, latex with neoprene, or sheer vinyl gloves. Do not use natural latex gloves.
- Patients with preexisting conditions that increase seizure risk should be monitored closely.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Lindane?
A: For scabies in adults, apply 30 mL (1 ounce) of lotion, or up to 60mL for larger individuals, to the entire body from the neck down, washing it off after 8-12 hours. For head lice, apply 30-60 mL of shampoo to dry hair, lather after 4 minutes, and rinse. Pediatric dosages should be adjusted for weight and surface area.
Q2: How does Lindane work?
A: Lindane is an insecticide that disrupts the nervous system function of scabies mites and lice, causing paralysis and death.
Q3: Can Lindane be used during pregnancy?
A: Lindane is not recommended during pregnancy due to potential fetal risks. Safer alternative treatments should be considered.
Q4: Is Lindane safe for breastfeeding mothers?
A: Lindane passes into breast milk. Breastfeeding should be discontinued for at least 24 hours after application. Pump and discard milk during this time.
Q5: What are the common side effects of Lindane?
A: Common side effects include skin irritation (itching, burning, dryness), rash, and mild dizziness.
Q6: Are there any serious side effects associated with Lindane?
A: Seizures are a rare but serious side effect, particularly with misuse or in high-risk individuals. Other serious but rare side effects include aplastic anemia and cardiac arrhythmias.
Q7: What should I do if Lindane gets into my eyes?
A: Immediately flush the eyes with water and seek medical attention if irritation persists.
Q8: Can Lindane be used on broken skin?
A: No, Lindane should not be applied to open wounds, cuts, or severely irritated skin.
Q9: How long does itching persist after using Lindane for scabies?
A: Itching may persist for several weeks even after successful treatment. This does not indicate treatment failure and is not a reason to reapply Lindane.
Q10: What are the contraindications to using Lindane?
A: Lindane is contraindicated in premature infants, individuals with a history of uncontrolled seizures, those with crusted scabies, and individuals with hypersensitivity to lindane.
Please note: This information is current as of February 16, 2025, and may be subject to change. Always consult with a qualified medical professional for the most up-to-date information and personalized advice.
