Usage
Crotamiton is prescribed for the treatment of scabies (caused by the mite Sarcoptes scabiei) and for the symptomatic relief of pruritus (itching) associated with various skin conditions such as eczema, dermatitis, insect bites, and chickenpox. Its pharmacological classifications include scabicide and antipruritic. While its exact mechanism of action as a scabicide isn’t fully understood, it appears to affect the mite’s motor system. Its antipruritic effect might be linked to inhibition of histamine, serotonin, and protease-activated receptor 2.
Alternate Names
Crotamiton is the generic name. A common brand name is Eurax.
How It Works
Pharmacodynamics: Crotamiton relieves itching and eliminates scabies mites. The precise mechanism for scabicidal action is unknown, but it appears to impact the mites’ neuromuscular system. The antipruritic effect is possibly related to its ability to inhibit histamine, serotonin, and protease-activated receptor 2.
Pharmacokinetics: Crotamiton is applied topically. It is absorbed systemically through the skin, achieving low plasma concentrations. Peak plasma levels are reached within 4-10 hours after application, after which they decline rapidly. The elimination pathways have not been extensively studied, but some excretion occurs through the urine. Specific metabolic pathways, including CYP enzyme involvement, are largely unknown.
Dosage
Standard Dosage
Adults:
Scabies: Apply a thin layer of the 10% cream or lotion to the entire body from the neck down (avoiding the face and scalp), massaging thoroughly into the skin, particularly in skin folds and creases. A second application is recommended 24 hours later. Bathe 48 hours after the second application. Treatment may be repeated after 7-10 days if live mites are still present.
Pruritus: Massage gently into affected areas until completely absorbed. Repeat as needed.
Children:
Scabies & Pruritus: For children under 3 years, application should be limited to once daily and done under medical supervision. For children 3 years and older, the dosage is generally the same as for adults. However, use in children should be guided by a physician, and a smaller quantity of cream should be applied compared to adult use.
Special Cases:
Elderly Patients: No specific dosage adjustments are generally required.
Patients with Renal Impairment: No specific dosage adjustments are outlined in available resources. However, caution should be exercised.
Patients with Hepatic Dysfunction: No specific dosage adjustments are outlined in available resources. However, caution should be exercised.
Patients with Comorbid Conditions: Consider potential interactions with existing medical conditions. Crotamiton is contraindicated in patients with acutely inflamed skin or raw or weeping surfaces until the acute inflammation subsides.
Clinical Use Cases
The supplied sources do not give information on clinical use cases for crotamiton in settings like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Crotamiton’s primary clinical use is limited to treating scabies and pruritus.
Dosage Adjustments
Adjustments may be necessary depending on the severity and location of the infestation. In cases of treatment failure, alternative scabicides should be considered.
Side Effects
Common Side Effects
Mild itching, rash, skin irritation, and a burning or warming sensation at the application site.
Rare but Serious Side Effects
Allergic reactions (hives, difficulty breathing, swelling of the face, lips, tongue, or throat), severe skin irritation, spreading of skin lesions.
Long-Term Effects
No specific long-term effects have been identified.
Adverse Drug Reactions (ADR)
Severe allergic reactions requiring immediate medical attention.
Contraindications
Hypersensitivity to crotamiton, acute exudative dermatoses, and application to severely inflamed skin or open wounds.
Drug Interactions
No clinically significant drug interactions have been consistently reported. However, some sources note possible interference with hormonal contraceptives. Always ascertain complete medication history including OTC drugs and supplements before prescribing.
Pregnancy and Breastfeeding
Pregnancy Safety Category: C. Use during pregnancy, particularly in the first trimester, is generally not recommended unless the potential benefit outweighs the risk to the fetus. The drug’s excretion in breast milk is unknown. Breastfeeding is not recommended while using crotamiton. If use is unavoidable, do not apply to the nipple area.
Drug Profile Summary
- Mechanism of Action: Scabicidal and antipruritic; exact mechanisms are unknown. Possibly inhibits histamine, serotonin, and protease-activated receptor 2 for antipruritic effects.
- Side Effects: Itching, rash, skin irritation, burning/warming sensation. Rarely, allergic reactions.
- Contraindications: Hypersensitivity to crotamiton, acute exudative dermatoses, application to inflamed or broken skin.
- Drug Interactions: Limited information available, possible reduced effectiveness of hormonal contraceptives.
- Pregnancy & Breastfeeding: Not generally recommended; Pregnancy Category C.
- Dosage: Topical, 10% cream or lotion. Adults/Children >3 years: Apply to affected areas; repeat in 24 hours for scabies. Children <3 years: Once daily under medical supervision.
- Monitoring Parameters: Observe for signs of skin irritation or allergic reactions. Assess the effectiveness of treatment for scabies.
Popular Combinations
No specific combination therapies involving crotamiton are routinely recommended.
Precautions
- General Precautions: Avoid contact with eyes, mucous membranes, and open wounds.
- Specific Populations: See “Pregnancy and Breastfeeding” and “Dosage - Children” sections.
- Lifestyle Considerations: No specific restrictions related to alcohol, smoking, diet, or driving. However, it’s crucial to maintain good hygiene practices to prevent scabies reinfestation.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Crotamiton?
A: See “Dosage” section.
Q2: How long does it take for Crotamiton to work for scabies?
A: Improvement in symptoms is usually observed within a few days, but complete eradication of mites may take longer. A repeat application after 7-10 days is often recommended.
Q3: Can Crotamiton be used on the face?
A: No, Crotamiton should be avoided on the face, especially near the eyes and mouth, due to the risk of irritation.
Q4: What should I do if I accidentally get Crotamiton in my eyes?
A: Rinse immediately and thoroughly with water. Seek medical attention if irritation persists.
Q5: Can I use Crotamiton if I’m pregnant or breastfeeding?
A: Crotamiton is generally not recommended during pregnancy, especially during the first trimester. Its safety during breastfeeding has not been established. Consult a physician before use.
Q6: Are there any drug interactions I should be aware of?
A: Limited information is available about drug interactions. However, some sources note a possible interaction with hormonal contraceptives, potentially reducing their effectiveness. Always provide your doctor with a complete list of your medications.
Q7: What are the common side effects of Crotamiton?
A: Common side effects include mild itching, rash, skin irritation, and a burning or warming sensation at the application site. These are usually transient and resolve on their own.
Q8: What should I do if my itching doesn’t improve after using Crotamiton?
A: Consult your doctor. Your condition might require a different treatment, or the scabies infestation may not have been completely eradicated.
Q9: Can I use Crotamiton for other skin conditions besides scabies and general itching?
A: Crotamiton is sometimes used to relieve itching associated with various skin conditions, such as eczema, dermatitis, chickenpox, and insect bites. However, consult your doctor before using it for anything other than scabies or general pruritus.
Q10: How should Crotamiton be stored?
A: Crotamiton should be stored below 30°C and protected from light.
