Arthropod and parasitic antibiotics

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


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


General Care

  • Wash all linens/clothes in hot water or bag bulky items and keep sealed for 2wks
  • Pruritus may continue for weeks despite successful elimination of infestation
    • Consider steroids for symptom relief


  • Permethrin 5% cream for all family members[2]
    • 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[3]
    • May require application head to toe (avoid mucus membranes)
    • Leave on for 8-12 hours, then wash off


  • Lindane - effective treatment but associated with potential for toxic manifestations (seizures, neurotoxicity)
    • Reserved for refractory cases


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)[4]

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


antibiotics should be continued for 5 days after the last recorded fever

  • Adults: Doxycycline 100mg PO/IV BID x 14 days
  • Pediatrics: under 45 kg use Doxycycline 2.2mg/kg PO/IV twice a day
  • Pregnant: Rifampin 300mg PO every 12 hours


For specific dosing see the CDC Recommendations or call the Malaria CDC Hotline(855) 856-4713

Uncomplicated Malaria

  • Uncomplicated:
    • No evidence of organ dysfunction
    • Parasitemia <5%
    • Able to tolerate PO
  • Hospitalize:
    • Severe clinical manifestations in non-immune host for P. falciparum or P. knowlesi
  • Report to state health department
  • For non-pregnant patients (3 day course)
    • Artemether + lumefantrine
    • Artesunate + amodiaquine
    • Artesunate + mefloquine
    • Dihydroartemisinin + piperaquine
    • Artesunate + sulfadoxine–pyrimethamine (SP)
  • For pregnant (1st trimester)
  • Additional considerations
    • Avoid artesunate + SP in HIV/AIDS patients taking co-trimoxazole
    • Avoid artesunate + amodiaquine in HIV/AIDS patients taking efavirenz or zidovudine

Severe Malaria

  • Do not delay treatment in the unstable patient if strong suspicion for malaria as initial smear may be falsely negative
  • Treatment (IV for ≥24 hours then 3 days PO course)
    • Artesunate (IV)
      • Clears malaria faster than quinine
      • Distributed only through CDC
    • Quinidine (IV) also appropriate choice; more available in US



  • 15mg/kg/day divided in 2 doses[5]
    • First line therapy


  • Second line therapy
  • 50-100mg/kg/day divided in 3 doses [6]

Rocky Mountain Spotted Fever

  • Doxycycline 100 mg BID for 5-7 days[7]
    • Indicated also in children at 2.2mg/kg BID
  • Chloramphenicol (CAM) 50-100 mg/kg/day div Q6hr (Max dose = 4g/day)
    • Preferred agent in pregnancy. May cause aplastic anemia and Grey baby syndrome, more common in near term or 3rd trimester[8]
    • Consideration should be made for doxycycline over CAM in the 3rd trimester


  1. Devore CD and Schutze G. Head Lice. Pediatrics. 2015; 135(5) e1355-e1365.
  2. Strong M. Johnstone P. Interventions for treating scabies. Cochrane Database Syst Rev. 2007;(3):CD000320
  3. Subramaniam S. Rutman MS. Wnger JK. A papulopustular, vesicular, crusted rash in a 4-week old neonate. Pediatric Emergency Care. 2013;29:1210-1212
  4. 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.
  5. Garcia HH, Pretell EJ, Gilman RH, et al. A trial of antiparasitic treatment to reduce the rate of seizures due to cerebral cysticercosis. N Engl J Med. 2004;350(3):249-58.
  6. Sotelo J. et al. Albendazole vs praziquantel for therapy for neurocysticercosis. A controlled trial. Arch Neurol. May 1988;45(5):532-4
  7. Shandera WX, Roig IL: Viral & Rickettsial Infections, in Papadakis MA, McPhee SJ (eds): Current Medical Diagnosis and Treatment, ed 52. USA, McGraw-Hill, 2013, (Ch) 32: p 1412-1413.