Treatment algorithm

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

asymptomatic

1st line – anthelmintic

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ACUTE
|
asymptomatic
1st line – 

anthelmintic

Treatment with an anthelmintic is indicated when adult worms are passed, or characteristic eggs are noted in the stool. First-line treatments include albendazole, mebendazole, or ivermectin.[45]​​ A chewable tablet formulation of mebendazole is available in some countries. Pyrantel is considered an acceptable alternative, but is rarely used in the US. Levamisole is also considered an acceptable alternative in some countries (and is on the WHO essential medicines list), but is not available in the US or Europe.[47]

Although widespread use of benzimidazoles in children has not revealed specific safety issues, there are limited data in patients <2 years of age.[24]​​[49][50] The World Health Organization (WHO) considers these drugs to be safe in children aged 12 months and older when used at appropriate doses.[51]​​​ Pyrantel can be used in patients of all ages.[52]

Risks and benefits of treatment should be weighed carefully before giving these drugs during pregnancy, particularly during the first trimester. If a woman in her first trimester of pregnancy is found to have ascariasis, she must wait until the second trimester to receive treatment. The WHO recommends the use of albendazole or mebendazole in the second and third trimesters of pregnancy.[51]​​​​

Primary options

albendazole: children 12 months to 2 years of age: 200 mg orally as a single dose; children ≥2 years of age and adults: 400 mg orally as a single dose

OR

mebendazole: children ≥2 years of age and adults: 500 mg orally as a single dose, or 100 mg twice daily for 3 days

OR

ivermectin: children ≥15 kg and adults: 150-200 micrograms/kg as a single dose

Secondary options

pyrantel: children and adults: 11 mg/kg orally as a single dose, maximum 1000 mg/dose

OR

levamisole: children and adults: consult specialist for guidance on dose

pneumonitis

1st line – symptomatic treatment

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ACUTE
|
pneumonitis
1st line – 

symptomatic treatment

Cough suppressants, antihistamines, bronchodilators, and corticosteroids may help control symptoms.[26] No anthelmintic has been shown to kill larvae during this migratory phase of infection.

gastrointestinal symptoms

1st line – anthelmintic

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ACUTE
|
gastrointestinal symptoms
|
no intestinal obstruction, hepatobiliary or pancreatic ascariasis
1st line – 

anthelmintic

Treatment with an anthelmintic is indicated when adult worms are passed, or characteristic eggs are noted in the stool. First-line treatments include albendazole, mebendazole, or ivermectin.[45]​ A chewable tablet formulation of mebendazole is available in some countries. Pyrantel is considered an acceptable alternative, but is rarely used in the US. Levamisole is also considered an acceptable alternative in some countries (and is on the WHO essential medicines list), but is not available in the US or Europe.[47]

Although widespread use of benzimidazoles in children has not revealed specific safety issues, there are no data in patients <2 years of age.[24]​​[49][50] The World Health Organization (WHO) considers these drugs to be safe in children aged 12 months and older when used at appropriate doses.[51]​ Pyrantel can be used in patients of all ages.[52]

Risks and benefits of treatment should be weighed carefully before giving these drugs during pregnancy, particularly during the first trimester. If a woman in her first trimester of pregnancy is found to have ascariasis, she must wait until the second trimester to receive treatment. The WHO recommends the use of albendazole or mebendazole in the second and third trimesters of pregnancy.[51]​​

Primary options

albendazole: children 12 months to 2 years of age: 200 mg orally as a single dose; children ≥2 years of age and adults: 400 mg orally as a single dose

OR

mebendazole: mebendazole: children ≥2 years of age and adults: 500 mg orally as a single dose, or 100 mg twice daily for 3 days

OR

ivermectin: children ≥15 kg and adults: 150-200 micrograms/kg as a single dose

Secondary options

pyrantel: children and adults: 11 mg/kg orally as a single dose, maximum 1000 mg/dose

OR

levamisole: children and adults: consult specialist for guidance on dose

1st line – anthelmintic plus supportive care

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ACUTE
|
gastrointestinal symptoms
|
with intestinal obstruction
1st line – 

anthelmintic plus supportive care

In cases of intestinal obstruction without complications (persistent abdominal pain, persistent tender abdominal mass, immobile abdominal mass after 24 hours of medical management, or signs of toxaemia), medical management is usually successful.[1][5][27][54]

Piperazine is the recommended first-line treatment in patients with intestinal obstruction. It paralyses adult ascarids, thereby allowing them to be naturally expelled from the gut by peristalsis. Patients should not receive concomitant chlorpromazine, as seizures may occur. Piperazine and pyrantel are antagonistic and should not be given together.

If piperazine is not available, albendazole, mebendazole, or pyrantel may also be used; however, caution should be exercised when using other anthelmintics, as they may be associated with causing or worsening obstruction.[55][56]

Supportive treatment with nasogastric suction, nothing by mouth, intravenous hydration, and electrolyte replacement should be instituted.[22][24]​​[25]

Primary options

piperazine: children: 75 mg/kg orally once daily for 2 days, maximum 3500 mg/day; adults: 3500 mg orally once daily for 2 days

Secondary options

albendazole: children 12 months to 2 years of age: 200 mg orally as a single dose; children ≥2 years of age and adults: 400 mg orally as a single dose

OR

mebendazole: children ≥2 years of age and adults: 500 mg orally as a single dose, or 100 mg twice daily for 3 days

OR

pyrantel: children and adults: 11 mg/kg orally as a single dose, maximum 1000 mg/dose

Consider – surgery

Back
ACUTE
|
gastrointestinal symptoms
|
with intestinal obstruction
Consider – 

surgery

Additional treatment recommended for SOME patients in selected patient group

Surgical intervention for removal of worm boluses is indicated if there is persistent abdominal pain, persistent tender abdominal mass, immobile abdominal mass after 24 hours of medical management, or signs of toxaemia.[57]

If the parasitic bundle cannot be manually moved towards the colon and expressed, an enterotomy may be necessary. In cases of gangrene or infarction, resection of affected bowel may be necessary.[52]

1st line – anthelmintic

Back
ACUTE
|
gastrointestinal symptoms
|
with hepatobiliary or pancreatic ascariasis
1st line – 

anthelmintic

Treatment with an anthelmintic is indicated when adult worms are passed, or characteristic eggs are noted in the stool. First-line treatments include albendazole, mebendazole, or ivermectin.[45]​ Pyrantel is considered an acceptable alternative, but is rarely used in the US. Levamisole is also considered an acceptable alternative in some countries (and is on the WHO essential medicines list), but is not available in the US or Europe.[47]

Although widespread use of benzimidazoles in children has not revealed specific safety issues, there are no data in patients <2 years of age.[24]​​[49][50] The World Health Organization (WHO) considers these drugs to be safe in children aged 12 months and older when used at appropriate doses.[51]​ Pyrantel can be used in patients of all ages.[52]

Risks and benefits of treatment should be weighed carefully before giving these drugs during pregnancy, particularly during the first trimester. If a woman in her first trimester of pregnancy is found to have ascariasis, she must wait until the second trimester to receive treatment. The WHO recommends the use of albendazole or mebendazole in the second and third trimesters of pregnancy.[51]​​

Primary options

albendazole: children 12 months to 2 years of age: 200 mg orally as a single dose; children ≥2 years of age and adults: 400 mg orally as a single dose

OR

mebendazole: children ≥2 years of age and adults: 500 mg orally as a single dose, or 100 mg twice daily for 3 days

OR

ivermectin: children ≥15 kg and adults: 150-200 micrograms/kg as a single dose

Secondary options

pyrantel: children and adults: 11 mg/kg orally as a single dose, maximum 1000 mg/dose

OR

levamisole: children and adults: consult specialist for guidance on dose

Plus – endoscopic retrograde cholangiopancreatography (ERCP) or surgery

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ACUTE
|
gastrointestinal symptoms
|
with hepatobiliary or pancreatic ascariasis
Plus – 

endoscopic retrograde cholangiopancreatography (ERCP) or surgery

Treatment recommended for ALL patients in selected patient group

Hepatobiliary and/or pancreatic involvement may present as one of the following syndromes: biliary colic, acalculous cholecystitis, acute cholangitis, acute pancreatitis, or hepatic abscess.

In well-resourced settings, obstructing worms can often be removed by ERCP.[5][27] Piperazine can also be used to paralyse worms, but some experts argue that this treatment impedes back-migration of worms from the biliary tree into the duodenum.[52]

If ERCP is not successful or available, surgery is the remaining alternative to relieve obstruction.[24]​​

Consider – analgesia

Back
ACUTE
|
gastrointestinal symptoms
|
with hepatobiliary or pancreatic ascariasis
Consider – 

analgesia

Additional treatment recommended for SOME patients in selected patient group

Patients with pancreatic or biliary colic require appropriate analgesia.

Primary options

morphine sulfate: children: 0.1 to 0.2 mg/kg intravenously/intramuscularly/subcutaneously every 2-4 hours when required, or 0.2 to 0.5 mg/kg orally (immediate-release) every 4-6 hours when required; adults: 2-15 mg intravenously/intramuscularly every 3-4 hours when required, or 10-30 mg orally (immediate-release) every 3-4 hours when required

Consider – broad-spectrum antibiotics

Back
ACUTE
|
gastrointestinal symptoms
|
with hepatobiliary or pancreatic ascariasis
Consider – 

broad-spectrum antibiotics

Additional treatment recommended for SOME patients in selected patient group

Patients with acute cholangitis due to impacted Ascaris lumbricoides often have secondary bacterial infection and sepsis, and should be treated with broad-spectrum antibiotics and other supportive measures such as fluid and electrolyte replacement, in addition to the removal of ascarid worms.[52] Local sepsis guidelines should be followed; choice of antibiotics depends on local resistance and susceptibility patterns.

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Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer

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