Which parasitic infections are treated with metronidazole (Flagyl) as a vermifuge?

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Last updated: October 9, 2026 • View editorial policy

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Flagyl (Metronidazol) como Vermífugo

Flagyl é eficaz principalmente contra um único parasita helmíntico: Trichomonas vaginalis (um protozoário, não um verme verdadeiro), e tem atividade limitada contra Giardia lamblia e Entamoeba histolytica. 1 2

Parasitas Tratados com Metronidazol

Protozoários (Atividade Principal)

Metronidazol é o tratamento de escolha para:

  • Trichomonas vaginalis - Taxa de cura de 90-95% com dose única de 2g ou 500mg duas vezes ao dia por 7 dias 3, 2
  • Giardia lamblia (giardíase) 4
  • Entamoeba histolytica (amebíase intestinal aguda e abscesso hepático amebiano) 1, 4

Helmintos (Atividade Muito Limitada)

Dracunculus medinensis (verme da Guiné):

  • Única evidência de eficácia contra um helminto verdadeiro
  • Taxa de cura de 85% com 400mg três vezes ao dia por 10-20 dias 5
  • Proporciona alívio sintomático da dor e prurido dentro de duas semanas
  • Nota importante: Esta é uma infecção rara, praticamente erradicada globalmente

O Que Metronidazol NÃO Trata

Metronidazol não é eficaz contra helmintos intestinais comuns:

  • Ascaris lumbricoides (lombriga)
  • Ancilostomídeos (hookworm)
  • Strongyloides stercoralis
  • Enterobius vermicularis (oxiúros)
  • Taenia spp. (tênia)
  • Trichuris trichiura

Para estes parasitas, são necessários outros anti-helmínticos como albendazol, mebendazol, ivermectina ou praziquantel 6.

Armadilha Clínica Importante

Não confunda "Trichomonas" com "Trichuris":

  • Trichomonas vaginalis = protozoário tratado com metronidazol
  • Trichuris trichiura = helminto (verme chicote) que NÃO responde ao metronidazol

Indicações Aprovadas pela FDA

Segundo a bula oficial, Flagyl está indicado para 1:

  • Tricomoníase sintomática e assintomática
  • Amebíase (disenteria amebiana e abscesso hepático)
  • Infecções bacterianas anaeróbicas (Bacteroides, Clostridium, etc.)

Metronidazol é fundamentalmente um antibiótico anaeróbio com atividade antiprotozoária, não um vermífugo de amplo espectro. 7, 4 Para desparasitação intestinal de helmintos, outros agentes são necessários.

References

5
Research

Metronidazole ("Flagyl") in dracunculiasis: a double blind study.

Annals of tropical medicine and parasitology, 1977

7
Research

Metronidazole is still the drug of choice for treatment of anaerobic infections.

Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2010

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