Key points
- Hymenolepiasis is caused by a parasitic worm, also known as the "dwarf tapeworm."
- People can get dwarf tapeworm by consuming food or water contaminated by dwarf tapeworm eggs.
- Dwarf tapeworm occurs worldwide, most often in people living in areas with poor sanitation and people living in institutional settings.
Treatment options
Praziquantel is the treatment of choice for dwarf tapeworm infections. Niclosamide and nitazoxanide are the alternative drug options.
Drug
Dosage
Notes
Praziquantel
Adults and children: 25mg/kg in a single dose.
Oral praziquantel is available for human use in the United States.
Niclosamide
Adults: 2gm in a single dose for 7 days.
Children 11 – 34 kg: 1 gm in a single dose on day one and then 500 mg per day orally for 6 days.
Children greater than 34 kg: 1 gm in a single dose on day one, and then 1 gm per day orally for 6 days.
Niclosamide is not available in the United States.
Nitazoxanide
Adults: 500 mg orally twice daily for 3 days.
Children aged 12 – 47 months: 100 mg orally twice daily for 3 days.
Children 4 – 11 years: 200 mg orally twice daily for 3 days.
Nitazoxanide is available for human use in the United States.
Care precautions
Praziquantel
Treatment in Pregnancy
Praziquantel is a pregnancy category B drug. There are no adequate and well-controlled studies in pregnant women. However, the available evidence suggests no difference in adverse birth outcomes in the children of women who were accidentally treated with praziquantel during mass drug administration (MDA) campaigns compared with those who were not. In MDA campaigns for which the World Health Organization (WHO) has determined that the benefit of treatment outweighs the risk, WHO encourages the use of praziquantel in any stage of pregnancy. For individual patients in clinical settings, healthcare providers should consider the risk of treatment in infected pregnant women with the risk of disease progression in the absence of treatment.
Pregnancy Category B: Either animal-reproduction studies have not demonstrated a fetal risk plus there are no controlled studies in pregnant women, or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters).
Treatment During Lactation
Praziquantel is excreted in low concentrations in breast milk. According to WHO guidelines for MDA campaigns, the use of praziquantel during lactation is encouraged. For individual patients in clinical settings, healthcare providers should consider the risk of treatment in infected breastfeeding women with the risk of disease progression in the absence of treatment.
Treatment in Pediatric Patients
The safety of praziquantel in children aged less than 4 years has not been established. WHO now recommends treating children at least 2 years of age with praziquantel during MDA campaigns for schistosomiasis control, citing evidence that praziquantel is safe in this age group. For individual patients in clinical settings, healthcare providers should consider the risk of treatment in children younger than 4 years old with the risk of disease progression in the absence of treatment.
Niclosamide
Treatment in Pregnancy
Niclosamide is a pregnancy category B drug. Data on the use of niclosamide in pregnant women are limited. Niclosamide is minimally absorbed from the gastrointestinal tract. Healthcare providers should consider the risk of treatment in infected pregnant women with the potential risk to the fetus in the absence of treatment.
Pregnancy Category B: Either animal-reproduction studies have not demonstrated a fetal risk plus there are no controlled studies in pregnant women, or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters).
Treatment During Lactation
It is not known whether niclosamide is excreted in breast milk, although niclosamide is minimally absorbed from the gastrointestinal tract. The World Health Organization (WHO) classifies niclosamide as compatible with breastfeeding, although there are limited data on the use of niclosamide during lactation.
Treatment in Pediatric Patients
The safety of niclosamide in children has not been established, although niclosamide is minimally absorbed from the gastrointestinal tract. Available evidence suggests that the safety profiles are comparable in children 2 years or older and adults.
Nitazoxanide
Treatment in Pregnancy
Nitazoxanide is a pregnancy category B drug. Data on the use of nitazoxanide in pregnant women are limited, and risk to the embryo-fetus is unknown. Healthcare providers should consider the risk of treatment in infected pregnant women with the potential risk to the fetus in the absence of treatment.
Pregnancy Category B: Either animal-reproduction studies have not demonstrated a fetal risk plus there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters).
Treatment during lactation
It is not known whether nitazoxanide is excreted in breast milk. Nitazoxanide should be used with caution in breastfeeding women.
Treatment in pediatric patients
Nitazoxanide tablets should not be used in children age 11 years or younger as a single tablet contains a greater dose than recommended for pediatric dosing. Nitazoxanide oral suspension may be used for dosing in children, although the safety in children age 1 and younger is not certain.