Product Monograph - Kwellada-P Lotion
ACTIONS AND CLINICAL PHARMACOLOGY
Permethrin, a synthetic pyrethroid, has a broad spectrum of insecticidal activity combined with high potency when applied topically to insects.
Like other pyrethroids permethrin is a sodium channel toxin. In susceptible nerve cells small amounts of permethrin cause a change in the kinetics of the sodium channel. Although the activation of the sodium current is unaffected, the rate of inactivation of the current is greatly slowed. This tail current, even at low doses, is adequate to cause repetitive activity. One normal action potential, in the presence of permethrin, leads to a series of abnormal action potentials. Consequently, there is repetitive firing of the neuron.
Clinical studies have demonstrated that permethrin is active against Sarcoptes scabiei, scabies.
In clinical trials 5% permethrin was found to be an efficacious treatment for scabies. After one application of 5% permethrin lotion 93% of patients were cured at 28 days. At the interim assessment at 14 days 37% were already cured and 61% were improving.
Only a very minimal amount of permethrin is absorbed when applied topically. In a bioavailability study it was determined that <0.032% of a topically applied dose of 5% permethrin lotion was absorbed.
INDICATIONS AND CLINICAL USE
Kwellada-P Lotion is indicated for the treatment of scabies Sarcoptes scabiei. One application of
Kwellada-P Lotion is usually adequate to eradicate the infestation of scabies. If new lesions appear or live scabies mites are seen, a second treatment can occur seven to ten days after the initial treatment.
CONTRAINDICATIONS
Kwellada-P Lotion is contraindicated in patients with a known sensitivity or reaction to permethrin, any components of the product, any pyrethroid, pyrethrin excipients, or to chrysanthemums.
WARNINGS
Kwellada-P Lotion should be discontinued if hypersensitivity occurs. In the event of accidental ingestion of permethrin, please seek immediate medical attention.
PRECAUTIONS
General: Permethrin is not an eye irritant, but contact with the eyes should be avoided because other components of the product may cause marked irritation. If this occurs, the eyes should be rinsed. During a scabies infestation the skin is often irritated resulting in erythema, edema and pruritus. These symptoms can be temporarily exacerbated after treatment with pruritus often persisting for several weeks after treatment. If skin irritation occurs and does not improve, consult a doctor. The treatment of eczematous-like reactions with corticosteroids should be withheld prior to treatment with permethrin, as there is a risk of exacerbating the scabies infestation by reducing the immune response to the mite. If applying routinely, wear gloves to avoid irritation. For best results use as directed – incorrect use may cause treatment failure.
Keep out of reach of children.
For external use only.
Use in Children: Kwellada-P Lotion is efficacious in children over 2 years of age. The safety and efficacy of Kwellada-P Lotion has not been established in children under the age of two months. For 2 years and up, use as directed. Do not use on children under 2 years of age.
Long sleeve shirts, pants, mittens and socks should be worn on young children to prevent any contact of the treated skin with the mouth.
Use in the Elderly: Patients over 70 years should be treated under medical supervision.
Use in Pregnancy: Safety has not been established during controlled clinical trials for use in pregnant women. Kwellada-P Lotion should be used when the expected benefits outweigh the potential risks.
Nursing Mothers: Because it is not known whether permethrin is excreted during lactation consideration should be given to discontinuing nursing during treatment with Kwellada-P Lotion or withholding treatment if it is not possible to discontinue nursing.
ADVERSE REACTIONS
Clinical trials have indicated that adverse reactions are reported infrequently. Adverse reactions which do occur are usually mild and resolve rapidly. They are local in nature.
In clinical trials burning, stinging and tingling were the most frequently reported adverse events with fewer than 1% of patients reporting them. The next most frequently reported event was pruritus followed by erythema which was reported by less than 0.02% of patients. Pruritus characteristically remains for several weeks after successful treatment. The itching gradually subsides with the natural loss of the upper layer of skin.
Other symptoms include paraesthesia, eczema, skin oedema, rash, skin irritation, skin discomfort, smarting, and pain of skin.
SYMPTOMS AND TREATMENT OF OVERDOSAGE
There has been no incidence of ingestion of Kwellada-P Lotion. In the event of accidental ingestion of permethrin, please seek immediate medical attention.
Symptoms of overdose may include dizziness, loss of appetite, nausea, vomiting, headache, weakness, seizures, and loss of consciousness.
For management of a suspected drug overdose, contact your regional Poison Control Centre.
DOSAGE AND ADMINISTRATION
Prior to application the skin should be clean, dry and cool. A hot bath should not be taken prior to treatment. The lotion should be thoroughly massaged into the skin from the neck to the soles of the feet, paying particular attention to the areas between the fingers and toes, under the fingernails and toenails, wrists, armpits, genital area and buttocks. Do not apply on head or face.
Kwellada-P Lotion disappears when rubbed gently into the skin; therefore it is not necessary for the patient to apply the medication until it remains detectable on the skin. If the hands are washed with soap and water during the treatment period, Kwellada-P Lotion should be reapplied.
The patient should put on clean clothes and leave the lotion in place for 12 to 14 hours. The lotion should then be thoroughly washed off during a shower or bath. Patients should again change into clean clothes.
One treatment is usually adequate to eliminate the scabies. However, if live scabies mites are present or new skin lesions appear a second application can be given seven to ten days later.
Kwellada-P Lotion should be shaken before use.
For External Use Only
PHARMACEUTICAL INFORMATION
- 1.
Drug Substance
Common Name: Permethrin
Chemical Name: 3-phenoxybenzyl-(1R,1S)-cis, trans-3-(2,2-dichloro vinyl)-2,2- dimethylcyclopropanecarboxylate
Molecular Weight: 391.29
Physical Form: a yellowish-brown viscous liquid
Solubility: insoluble in water, soluble in or miscible with most organic solvents
(acetone, chloroform, cyclohexanone, ethanol, ether, hexane, methanol, dichloromethane, xylene)
Boiling Point: 198° - 200° C at 0.3 mm Hg
- 2.
Composition
Kwellada-P Lotion contains permethrin cis/trans ratio of 25:75. It also contains carbomer
980, edetate sodium, imidurea, methylparaben, polysorbate 20, propylene glycol, propylparaben, purified water, sorbitan monolaurate and sodium hydroxide.
- 3.
Stability and Storage Recommendations
Kwellada-P Lotion should be stored between 15o and 30oC.
AVAILABILITY OF DOSAGE FORMS
Kwellada-P Lotion is available in plastic bottles containing 100 mL lotion.