Key points
- Treatment with either mebendazole or albendazole is recommended.
- If a patient does not start treatment within the first several days of infection, prolonged or repeated courses of treatment may be necessary.
- Consider safety precautions of medications in different populations.
Overview
Prompt treatment with antiparasitic drugs can help prevent the progression of trichinellosis by killing the adult worms and so preventing further release of larvae. Once the larvae have become established in skeletal muscle cells, usually by 3 – 4 weeks post infection, treatment may not completely eliminate the infection and associated symptoms. In addition to antiparasitic medication, treatment with steroids is sometimes required in more severe cases.
Medications
The recommended treatment of trichinellosis is either mebendazole or albendazole. If treatment is not initiated within the first several days of infection, more prolonged or repeated courses of treatment may be necessary.
Safety
Both drugs are considered relatively safe but have been associated with side effects including bone marrow suppression. Patients on longer courses of therapy should be monitored by serial complete blood counts to detect any adverse effects promptly and discontinue treatment. Albendazole and mebendazole are not approved for use in pregnant women or children under the age of 2 years.
Drug
Dose and duration
Albendazole
Adult and pediatric dose: 400 mg twice a day by mouth for 8 – 14 days
Mebendazole
Adult and pediatric dose: 200 – 400 mg three times a day by mouth for 3 days, then 400 – 500 mg three times a day by mouth for 10 days
Oral albendazole and mebendazole are available for human use in the United States.
Care precautions
Treatment in Pregnancy
Albendazole is a pregnancy category C drug. There are limited data on the use of albendazole in pregnant women. The available evidence suggests no difference in congenital abnormalities in the children of women accidentally treated with albendazole 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 benefits of treatment outweigh the risks, WHO allows use of albendazole in the 2nd and 3rd trimesters of pregnancy. However, healthcare providers should balance the risks of treatment for the fetus with the risks of disease progression in the woman in the absence of treatment.
Pregnancy Category C: Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal, or other) plus there are no controlled studies in women, or studies in women and animals are not available. Prescribe albendazole only if the potential benefits to the woman justify the potential risks to the fetus.
Treatment during lactation
Albendazole is minimally excreted in human milk. WHO has concluded that a single oral dose of albendazole can be given to lactating women.
Treatment in pediatric patients
The safety of albendazole in children less than 6 years old is not certain. Studies of the use of albendazole in children as young as one year old suggest that it is safe. According to WHO guidelines for MDA campaigns, children as young as one year of age (able to safely swallow tablets) can take albendazole. These campaigns have treated many children under six years old with albendazole, albeit at a reduced dose.
Treatment in Pregnancy
Mebendazole is a pregnancy category C drug. Data on the use of mebendazole in pregnant women are limited. The available evidence suggests no difference in congenital anomalies in the children of women treated with mebendazole during mass drug administration (MDA) campaigns compared with those who were not. In MDA campaigns in countries where soil-transmitted helminths are common, World Health Organization (WHO) has determined that the benefits of treatment outweigh the risks and WHO allows use of mebendazole in the 2nd and 3rd trimesters of pregnancy. However, in a pregnant woman infected with a soil-transmitted helminth, balance the risks of treatment for the fetus with the risks of disease progression in the woman in the absence of treatment.
Pregnancy Category C: Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal, or other) plus there are no controlled studies in women, or studies in women and animals are not available. Prescribe mebendazole only if the potential benefits to the woman justify the potential risks to the fetus.
Treatment during lactation
Mebendazole is minimally excreted in breast milk. WHO classifies mebendazole as compatible with breastfeeding and allows its use in lactating women.
Treatment in pediatric patients
The safety of mebendazole in children is unclear. There are limited data in children under 2 years old. The WHO Model List of Essential Medicines for Children lists mebendazole as an intestinal antihelminthic medicine that can be used for children older than 2 years of age.