Usage
- Cetrimide + Gamma Benzene Hexachloride is prescribed for the treatment of scabies (a contagious skin infestation caused by the Sarcoptes scabiei mite) and pediculosis (lice infestation). It is also used as an antiseptic for minor wounds, cuts, and burns to prevent infection.
- Pharmacological classification: Antiparasitic, antiseptic, scabicide, pediculicide.
- Mechanism of action: Cetrimide acts as an antiseptic by disrupting bacterial cell membranes. Gamma benzene hexachloride (lindane) is a neurotoxic agent that disrupts the nervous system of parasites like mites and lice, leading to paralysis and death.
Alternate Names
- Gamma benzene hexachloride is also known as lindane.
- Brand names include Scabex, Scabiped, and Scabigard.
How It Works
- Pharmacodynamics: Cetrimide disrupts the cell membranes of bacteria, fungi, and some viruses. Lindane is absorbed through the parasite’s exoskeleton and acts on the nervous system, causing seizures and death.
- Pharmacokinetics: Cetrimide is poorly absorbed through intact skin. Lindane is absorbed through intact skin, especially when applied for prolonged periods or over large areas. It is metabolized in the liver and excreted primarily through the kidneys.
- Mode of action: Cetrimide acts as a cationic surfactant, disrupting the cell membranes of microorganisms. Lindane interferes with neuronal transmission by blocking GABA receptors, leading to uncontrolled nerve firing in the parasite.
- Elimination: Cetrimide is minimally absorbed and mostly removed by washing. Lindane is primarily excreted in urine, with some fecal elimination.
Dosage
Standard Dosage
Adults: Apply a thin layer of the lotion or cream to the entire body from the neck down, including the soles of the feet. Wash off thoroughly after 8-12 hours. For shampoo, apply to dry hair for 4 minutes, lather with water, and rinse thoroughly.
Children: Use with caution in children, especially those weighing less than 50 kg. The dosage should be determined by a physician based on weight and age.
Special Cases:
- Elderly Patients: Use with caution. They may be more susceptible to neurotoxic side effects.
- Patients with Renal Impairment: Use with caution as lindane is primarily excreted renally. Dosage adjustments may be necessary.
- Patients with Hepatic Dysfunction: Use with caution due to hepatic metabolism of lindane. Dose adjustments may be necessary.
- Patients with Comorbid Conditions: Use with extreme caution in patients with seizure disorders, pre-existing skin conditions (e.g., atopic dermatitis, psoriasis), or a history of neurotoxicity.
Clinical Use Cases
Cetrimide + Gamma Benzene Hexachloride is not typically indicated for use in clinical settings like intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations. It is primarily used for outpatient treatment of scabies and lice infestations.
Dosage Adjustments
Dosage adjustments should be made for patients with renal or hepatic impairment, low body weight (<50 kg), and a history of seizures.
Side Effects
Common Side Effects
- Pruritus (itching)
- Burning sensation
- Skin irritation
- Dry skin
- Rash
Rare but Serious Side Effects
- Seizures
- Neurotoxicity (dizziness, headache, paresthesia)
- Aplastic anemia
- Blood dyscrasias
Long-Term Effects
Chronic exposure to lindane can potentially lead to neurological complications.
Adverse Drug Reactions (ADR)
Severe neurotoxicity, including seizures and death, has been reported, even with single applications, particularly in children, the elderly, and individuals weighing less than 50 kg.
Contraindications
- Hypersensitivity to cetrimide or lindane
- Premature infants
- Uncontrolled seizure disorders
- Pregnancy (except in situations where the benefits outweigh the risks)
- Breastfeeding (should be used with caution)
- Crusted (Norwegian) scabies
- Severe skin conditions (e.g., atopic dermatitis, psoriasis)
Drug Interactions
- Oils and oil-based preparations may enhance absorption and increase the risk of toxicity.
- Medications that lower the seizure threshold should be used with caution.
- No specific drug-food interactions have been noted.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: C (use only if the benefits outweigh the risks)
- Lindane can cross the placenta and has been associated with an increased risk of birth defects.
- Breastfeeding: Lindane is excreted in breast milk. Use with caution and avoid applying to the breast area.
Drug Profile Summary
- Mechanism of Action: Cetrimide: disrupts bacterial cell membranes; Lindane: interferes with neuronal transmission in parasites.
- Side Effects: Pruritus, burning sensation, skin irritation, seizures (rare), neurotoxicity (rare).
- Contraindications: Hypersensitivity, premature infants, seizures, pregnancy, breastfeeding (caution), crusted scabies.
- Drug Interactions: Oils/oil-based products, drugs lowering seizure threshold.
- Pregnancy & Breastfeeding: Use with caution.
- Dosage: Apply thinly to affected area, wash off after 8-12 hours (lotion/cream), or 4 minutes (shampoo).
- Monitoring Parameters: Observe for signs of neurotoxicity (dizziness, headache, seizures).
Popular Combinations
Cetrimide + Gamma Benzene Hexachloride is typically used as a single-agent formulation. There are no established popular drug combinations.
Precautions
- Avoid contact with eyes, mucous membranes, and broken skin.
- Do not use for prolonged periods or over large areas.
- Monitor for signs of neurotoxicity.
- Advise patients about potential side effects and proper application technique.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Cetrimide + Gamma Benzene Hexachloride?
A: Apply a thin layer to affected area, wash off after 8-12 hours (cream/lotion) or 4 minutes (shampoo). Consult a physician for pediatric dosing.
Q2: What are the common side effects?
A: Itching, burning, skin irritation, dryness.
Q3: What are the serious side effects?
A: Seizures, neurotoxicity. Seek immediate medical attention if these occur.
Q4: Can this be used during pregnancy?
A: Only if the benefits clearly outweigh the risks, as lindane can be harmful to the fetus.
Q5: Can this be used while breastfeeding?
A: Use cautiously. Avoid applying to the breast area. Consult a physician.
Q6: What should I do if I accidentally get it in my eyes?
A: Immediately flush the eyes with plenty of water.
Q7: How long does the itching last after treatment?
A: Itching may persist for several weeks as a reaction to dead mites. This doesn’t indicate treatment failure.
Q8: Should I treat my entire family if one member has scabies?
A: Yes, scabies is highly contagious, so treating all close contacts is recommended, even if asymptomatic.
Q9: Can I use this on broken skin?
A: Avoid applying to broken skin, as this may increase absorption and risk of side effects.
