Topical organophosphate antiparasitic
Malathion
Brand names: Derbac-M, Quellada M
Adult dose
Dose: Apply lotion to affected area, leave on per product (8–12h for scabies, 12h for head lice), then wash off; repeat at 7 days
Route: Topical
Frequency: weekly x 2
Clinical pearls
- Head lice (alcoholic lotion preferred — water-based less effective); scabies if permethrin unsuitable
- Apply to dry hair; washing too soon reduces efficacy
Contraindications
- Hypersensitivity
- Asthma (caution with alcohol-based lotions)
Side effects
- Local irritation
- Hypersensitivity
Reference: BNF; NICE CKS; https://bnf.nice.org.uk/drugs/malathion/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Pathways
- Suspicious Pigmented Lesion — Melanoma Pathway · NICE NG14 2015 / BAD
- Cellulitis and Erysipelas · NICE NG141 2019 / CREST
- Psoriasis — Severity Assessment and Step-Up Therapy · NICE NG153 2019 / BAD
- Atopic Eczema — Assessment and Step-Up Therapy · NICE NG95 2023
- Urticaria and Angioedema · BSACI / EAACI Guidelines 2022
- Acne Vulgaris — Grading and Treatment · NICE NG198 2021 / BAD