Arthropod and parasitic antibiotics

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Antibiotics by diagnosis

For antibiotics by organism see Microbiology (Main)


Over the Counter (OTC)

  • Permethrin 1% lotion shampoo (if >2 months old)[1]
    • Wash hair with non-conditioned shampoo
    • Apply Permethrin for 10 min and rinse
    • Repeat on day 9
  • Pyrethrin lotion
    • Apply to affected areas and wash off after 10 min
    • Repeat in 7 days
  • Dimethicone therapy
    • First, apply the product to dry hair, then wait 10 min. Next, with product still in the hair, separate hair into small sections and comb hair to remove lice and eggs. Use a lice comb to remove lice and their eggs from hair. Finally, shampoo hair thoroughly with regular shampoo and warm water. Repeat as needed.[2]


Reserved for failed OTC treatment

  • Spinosad 0.9% topical suspension (if >6 months old)
    • Apply to scalp and air and wash off after 10 min.
    • Repeat in 10 days
  • Malathion 0.5% lotion (if >6 years old)
    • Applied to affected areas and wash after 8 hrs
    • Repeat in 7 days
  • Benzyl Alcohol 5% lotion (> 6 months old)
    • Apply to dry hair and wash off after 10 min
    • Repeat in 7 days
  • Ivermectin 400mcg/kg PO
    • Once on day 1 THEN once in 7 days
    • Reserved for patients failing topical treatment
  • Lindane therapy
    • Only consider if patient has failed two prior prescription treatments
    • Avoid in children <50 kg due to seizure association

Eyelash Infestation

  • Apply ophthalmic petroleum jelly q12hrs x 10 days

Pediatrics <2yo

  • Wet combing is an alternative to medical therapy


Treatment targeted against Enterobius vermicularis

  • Mebendazole 100mg PO once THEN repeat in 2 weeks OR
  • Albendazole 400mg PO once (100mig if < 2yo) THEN repeat in 2 weeks OR
  • Pyrantel Pamoate (Pin-x) 11mg/kg (max 1g) THEN repeat in 2 weeks
    • Recommended for pregnant patients



  • Permethrin 5% cream for all family members[3]
    • Apply from neck down
    • Leave on for 8-12hr before washing off
    • Has 95-98% success rate, may reapply in 1-2wks if incomplete effect
  • Ivermectin 200 mcg/kg may be necessary for severe infection
    • Also viable option in adolescent or adult with insecure social situation
    • Success rate 70%, increases if give repeat dose 2wks after
    • Contraindicated in lactating women and children < 15kg


  • Permethrin 5% is FDA approved for > 2 months of age although still recommended for neonatal scabies[4]
    • May require application head to toe (avoid mucus membranes)
    • Leave on for 8-12 hours, then wash off


Each regimin is for 10 days duration and option 1 is often used for mild parasitemia <4% with option two for sever cases with >4% parasite load

Option 1

Atovaquone (750mg BID) and Azithromycin (500-1000mg on first day, 250-1000mg on subsequent days)[5]

Option 2


  • 600 mg PO q8h x 7-10 days
  • Alt: 300-600mg IV q6h x 7-10 days
    • First Dose: 300-600mg IV x 1
  • Give with Quinine (650mg TID); use IV for severe infections


  • Clindamycin 20mg/kg/day for children and 25mg/kg/day for children for 7-10 days


  1. Devore CD and Schutze G. Head Lice. Pediatrics. 2015; 135(5) e1355-e1365.
  2. Ihde ES, Boscamp JR, Loh JM, Rosen L. Safety and efficacy of a 100% dimethicone pediculocide in school-age children. BMC Pediatr. 2015;15:70.
  3. Strong M. Johnstone P. Interventions for treating scabies. Cochrane Database Syst Rev. 2007;(3):CD000320
  4. Subramaniam S. Rutman MS. Wnger JK. A papulopustular, vesicular, crusted rash in a 4-week old neonate. Pediatric Emergency Care. 2013;29:1210-1212
  5. Krause PJ, Lepore T, Sikand VK, Gadbaw J Jr, Burke G, Telford SR 3rd, et al. Atovaquone and azithromycin for the treatment of babesiosis. N Engl J Med. Nov 16 2000;343(20):1454-8.