13.10.4 Parasiticidal preparations

Click here for head lice.

Click here for pubic lice.

Scabies

ChoiceDrugDosage
1st choice

Permethrin cream 5%

 

Encourage purchase OTC or referral to Minor Ailments Service

Dose:
Apply over the whole body including face, neck, scalp and ears and wash off after 8-12 hours. 30g tube of cream will cover the average person. Repeat application after 7 days to kill any larvae that hatch from eggs that survived the first application.
If hands are washed with soap within 8 hours of preparation, they should be treated again with cream

2nd choice

Malathion 0.5% liquid in an aqueous base (Derbac- M®)

Encourage purchase OTC or referral to Minor Ailments Service

Dose:
Apply over the whole body and wash off after 24 hours. 100mls will cover an average person. Repeat application after 7 days to kill any larvae that hatch from eggs that survived the first application.
If hands are washed with soap within 24 hours, they should be retreated

 

Prescribing Notes

  • Refer to BAD website for patient information leaflet on scabies.
  • All members of the household and close contacts should be treated simultaneously.
  • Aqueous preparations are preferable. Alcoholic solutions are not recommended due to irritation of excoriated skin and the genitalia.
  • Treatment should be applied to the whole body including the scalp, neck, face, and ears. Particular attention should be paid to the webs of fingers and toes and lotion brushed under the ends of nails.
  • Clothes and bed linen should be washed at normal temperatures at time of treatment.
  • Malathion and permethrin should be applied on two occasions for treatment at least one week apart.
  • It is important to warn users to re-apply treatment to the hands if they are washed.
  • The itch, and eczema, of scabies can persist for 4-6 weeks after the infestation has been eliminated and treatment for pruritus and eczema may be required. Crotamiton, a topical corticosteroid, or a sedating antihistamine at night may be of benefit.

Head Lice

ChoiceDrugDosage
1st choice

Dimeticone 4% lotion (Hedrin®) 50mls, 120ml spray pack ,150mls

Encourage purchase OTC or referral to Minor Ailments Service

Dose:
Rub into dry hair and scalp, allow to dry naturally, shampoo after a minimum of 8 hours (or overnight); repeat application after 7 days
2nd choice

Malathion 0.5% liquid in an aqueous base (Derbac- M®)

 

Encourage purchase OTC or referral to Minor Ailments Service

Dose:
Rub into dry hair and scalp, allow to dry naturally, removing by washing after 12 hours. Repeat application after 7 days

Prescribing Notes

  • Head lice can be managed and treated in community pharmacy under the NI Minor Ailments Service. A variety of products are also available to purchase over-the-counter.
  • Dimeticone coats head lice and interferes with water balance in lice preventing the excretion of water; it is less active against eggs and treatment should be repeated after 7 days.
  • Head lice must be seen before any insecticidal treatments are used. Nits (empty egg shells) do not constitute an infection. Treat only if head lice are found.
  • There is no need to treat members of the family or close contacts that do not have head lice. However, all affected household members should be treated simultaneously.
  • Head lice should be treated with lotion or liquid. Products with short application times e.g. cream rinse and mousse formulations, are not recommended. Shampoos are diluted too much during use to be effective and should not be used.
  • Aqueous formulations are preferred in severe eczema and in asthmatic patients.
  • In general, a course of treatment for head lice should be 2 applications of product 7 days apart to kill lice emerging from eggs that survive the first application.
  • In pregnancy, dimeticone or wet combing are preferred. If malathion is required the liquid in aqueous base should be used.
  • A mixture of white soft paraffin 50%/liquid paraffin 50% mix can be used in some cases to remove headlice ; the white soft paraffin/liquid paraffin mix should be applied to the head and left on overnight; wash out with a tar-based shampoo in the morning.

Caution

  • Keep hair away from sources of ignition, especially naked flames and burning cigarettes, whilst being treated with dimethicone 4% lotion (Hedrin®). Treated hair can readily burn if ignited.

Pubic Lice

ChoiceDrugDosage
1st choicesMalathion 0.5% liquid in an aqueous base (Derbac- M®)

Dose:
Apply over whole body, allow to dry naturally, wash off after 12 hours or overnight. Repeat applications after 7 days

or
Permethrin cream 5% Dose:
Apply over whole body, allow to dry naturally, wash off after 12 hours or overnight. Repeat applications after 7 days

Prescribing Notes

  • Consider referral to genito urinary medicine (GUM) clinic.
  • An aqueous preparation should be applied to all parts of the head and body for 12 hours or overnight; a second treatment is needed after 7 days to kill lice emerging from surviving eggs.
  • Alcoholic lotions are not recommended due to irritation of excoriated skin and genitalia.
  • Products should be applied to beards and moustaches but not applied to the face or scalp hair.
  • Aqueous malathion lotion is effective for pubic lice affecting the eye lashes.
  • A different insecticide should be used if a treatment course fails.

 

 

 

 

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