Permethrin INN 5% W/W
Scameth cream contains 5% w/w Permethrin in a smooth, white, water miscible base. Each 100 gm Scameth cream contains 5 gm of permethrin.
Scameth cream is indicated for the treatment of scabies and crab lice infestations.
Dosage & Administration:
In view of the great individual in body surface area and skin type, precise recommendations are not possible. The following table indicates the approximate amount of cream to be used as single application:
Adults and children (over 12 years) : Up to 1 tube
5-12 years: Up to 1/2 of a tube
1-5 years: Up to 1/4 of a tube
2 months - 1 year: Up to 1/8 of a tube
A few adults may need more than one tube (30 gm of cream) for whole body application, however the maximum amount of Scameth cream used in one application should be limited up to two tubes (60 gms of cream). Ensure that the skin is clean, dry and cool prior to treatment.
Treatment Procedure For Adults (Excluding The Elderly & Children over 2 Years):
Apply Scameth cream into the skin over the whole body, excluding the head, paying particular attention to the areas between the fingers and toes, wrists, axillae, external genitalia and buttock. The whole body should be washed thoroughly 8-12 hours after treatment. If any area of the body is subsequently washed with soap and water during the treatment period, Scameth cream should be reapplied.
Nature of the cream is such that it disapperars when rubbed gently into the skin. It is therefore not neccessary to apply the cream remains detectable on the surface.
In the majority of individuals, scabies infection is cleared with a single tube (30 gm) application. If necessary, maximum 2 tubes (60 gm) can be used as a single dose. Avoid areas close to the eyes.
Mode of Action:
The principal physiological action in insects exposed to Permethrin is induction of electrochemical abnormalities across the membranes of excitable cells, leading to hyperexcitability, incoordination and prostration. It is assumed that the mode of action against mites is similar.
Permethrin is rapidly metaboized by ester hydrolysis to inactive metabolites which are excreted primarily in the urine. Less than 0.5% of applied Permethrin is absorbed during the first 48 hours.
Use of Scameth cream is contra-indicated in individuals with a known allergy to Permethrin, its components, other pyrethroids or pyrethrins.
Precautions / Warnings:
For external use only. Avoid contact of Scameth cream with the eyes. In the event of inadvertent eye contamination, rinse with water, or normal saline if possible. When applying Scameth cream to the face in children, care should be taken when applying to areas close to the eyes and mouth, where it may be licked off. Nursing staff who routinely come with the cream may wear gloves to avoid any possible irritation to the hands.
Skin discomfort, usually described as burning or stinging, oedema, eczema, rash and pruritis are considered to be part of the natural history of scabies. In some treated patients, itching may persist because of allergic reactions to the dead mites under the skin and does not neccessarily signify a treatment failure.
Permethrin does not have the potential to induce mutagenic changes.
Permethrin has no significant oncogenic potential in human.
No evidence of teratogenicity has been found in mice, rats or rabbits.
Pregnancy and Lactation:
There is limited data in the use of Scameth cream in pregnancy, however, there is no indication of any risk to the foetus. The amount of Permethrin absorbed is extremely low, less than 0.5%. Any risk to the foetus following treatment with Scameth is minimal. It is not known whether Permethrin is excreted in human breast milk. So it should not be used in nursing mothers.
There are no known drug interactions with Permethrin. Treatment with coricosteroids in eczematous conditions should be discontinued, as there is a risk of exacerbating the scabies infestation by reducing the immune response to the mite.
Toxicity and Treatment of Overdosage:
No instance of overdosage of Scameth cream has been reported. Application of full tube of cream to a 2 month-old-child would result in a dose of approximately 350 mg/kg body weight to the skin. It is unlikely that such a dose would cause overt signs of toxicity even if 100% of the Permethrin was absorbed. It is unliked that massive over dosage of Permethrin would result in localised adverse reactions described above.
Treatment of Overdosage:
Symptomatic prescription is indicated. In case of accidental ingestion by a child, gastric lavage should be done within 2 hours of ingestion.
Pharmaceutical Precautions and Recommendations:
Store in cool dry place. Do not freeze. Use only on medical advice.
Keep all medicines out of the reach of children.
30 g tubes.