Ivermectin Pediatric Dose Calculator by Weight
Use this ivermectin pediatric dose calculator by weight to check a prescription against the FDA label weight table. Pick the diagnosed condition to get the number of 3 mg tablets, the exact mcg/kg dose, and the repeat-dose plan.
FDA label weight table, 3 mg tablets
How the ivermectin dosage calculator works
Oral ivermectin for people comes only as 3 mg tablets in the US, so the dose is a whole number of tablets chosen from the FDA Stromectol label weight table for the diagnosed condition. There is no approved oral liquid, and the calculator never converts to mL.
Formula
exact dose (mg) = weight in kg x 0.2 mg/kg (strongyloidiasis, scabies) or 0.15 mg/kg (onchocerciasis); tablets = FDA label weight-band count, or the exact dose rounded to the nearest 3 mg tablet above the table.
Worked example
A 20 kg child with strongyloidiasis: 20 kg x 0.2 mg/kg = 4 mg exact. The label table for 15-24 kg gives 1 x 3 mg tablet (3 mg) as a single dose. The same child with onchocerciasis (0.15 mg/kg = 3 mg) also takes 1 tablet.
Safety checks before using the result
- Under 15 kg is off-label: the FDA label says safety and effectiveness are not established. For scabies only, the calculator shows the weight-based dose from 5 kg with a warning summarizing newer trials; it gives no dose under 5 kg, or under 15 kg for other conditions.
- Never use veterinary ivermectin. Animal products are far more concentrated and have caused serious poisonings.
- Screen for Loa loa exposure (Central or West Africa) before treatment, and monitor INR with warfarin.
Practical dosing guide
Before you measure the dose
Use this page to match the diagnosed condition and the child's weight to the number of 3 mg ivermectin tablets on the FDA label before the first dose.
- What it is usually used for
- Ivermectin is an oral antiparasitic (3 mg tablets) FDA-approved for intestinal strongyloidiasis and onchocerciasis, and used per CDC guidance for scabies, cutaneous larva migrans, and off-label head lice in children weighing 15 kg or more.
- Common forms
- Common forms include 3 mg tablet.
- How the schedule is usually written
- Most plans are a single dose; scabies uses a second dose 7 to 14 days after the first.
Ivermectin pediatric medication summary
Ivermectin is an oral antiparasitic (3 mg tablets) FDA-approved for intestinal strongyloidiasis and onchocerciasis, and used per CDC guidance for scabies, cutaneous larva migrans, and off-label head lice in children weighing 15 kg or more.
FDA label doses: about 200 micrograms (mcg) per kg (0.2 mg/kg) as a single dose for strongyloidiasis and about 150 mcg/kg for onchocerciasis, given on an empty stomach with water. CDC scabies guidance uses 200 mcg/kg taken with food, two doses 7 to 14 days apart.
Strongyloidiasis usually needs no additional doses, but follow-up stool exams are needed and retreatment is indicated if larvae recur. Scabies and oral lice regimens use a planned second dose.
Ivermectin indications and common pediatric uses
Oral ivermectin is FDA-approved for intestinal strongyloidiasis and onchocerciasis, and CDC lists it for scabies, cutaneous larva migrans, and (off-label) head lice. It is not authorized or approved by the FDA for preventing or treating COVID-19.
Strongyloidiasis (intestinal)
Onchocerciasis
Scabies (classic and crusted)
Cutaneous larva migrans
Head lice (oral tablets)
How to give Ivermectin
- Administration guidance for pediatric oral ivermectin (3 mg tablets).
- Weigh the child on treatment day. Use the FDA label weight table to find the number of 3 mg tablets: about 200 mcg/kg for strongyloidiasis, about 150 mcg/kg for onchocerciasis. Follow the indication-specific food instruction: FDA-labeled tablet regimens direct dosing on an empty stomach with water, while CDC scabies guidance recommends taking oral ivermectin with food to increase bioavailability. Schedule the repeat dose when the prescribed plan includes one: 7 to 14 days after the first dose for classic scabies, or 9 to 10 days for off-label oral treatment of head lice.
Ivermectin side effects, contraindications, and interactions
Oral ivermectin side effects are uncommon at standard doses. In FDA label strongyloidiasis trials (109 patients), dizziness and itching were each reported in 2.8% of patients, and nausea and diarrhea in 1.8% each. Rare but serious effects include neurotoxicity (confusion, severe drowsiness, coma), seizures, severe skin reactions, and hepatitis; these need urgent evaluation.
Common side effects
- Watch for dizziness, nausea, diarrhea, and itching on the dosing day; each was reported in under 3% of strongyloidiasis trial patients (FDA label).
- Tell expected mild itch apart from severe allergy or skin reaction signs (facial swelling, wheeze, blistering or peeling rash).
- After onchocerciasis treatment, expect possible itching, rash, fever, joint pain, and lymph node swelling in the first 4 days, and check for eye symptoms.
Safety checks
- Hypersensitivity to ivermectin or any component of the product (FDA label)
- Children weighing less than 15 kg: safety and effectiveness have not been established (FDA label); CDC advises against ivermectin tablets in this group. Any use below 15 kg is off-label and must be directed by the prescriber (ideally with pediatric infectious disease input)
- Confirmed or suspected Loa loa infection (CDC); pretreatment assessment is needed after significant exposure to Loa loa-endemic areas of West or Central Africa (FDA label)
- Pregnancy: the FDA label states ivermectin should not be used during pregnancy because safety has not been established
- Breastfeeding: ivermectin is excreted in human milk in low concentrations; the FDA label advises treatment only when the risk of delayed treatment to the mother outweighs the possible risk to the newborn
- Hyperreactive onchodermatitis (sowda): these patients may be more likely to have severe reactions after microfilaricidal drugs (FDA label)
Drug interactions
- Review the full medication list with a clinician or pharmacist before combining therapies.
Ivermectin mechanism and clinical pearls
Ivermectin is an avermectin antiparasitic. It binds selectively and with high affinity to glutamate-gated chloride channels in invertebrate nerve and muscle cells, increasing chloride permeability and causing hyperpolarization, paralysis, and death of the parasite. It may also interact with other ligand-gated chloride channels, such as GABA-gated channels. Its selectivity comes from the fact that some mammals lack glutamate-gated chloride channels, avermectins have low affinity for mammalian ligand-gated chloride channels, and ivermectin does not readily cross the blood-brain barrier in humans (FDA label).
Weigh the child before prescribing and use the FDA label weight table for the number of 3 mg tablets. The bands differ by indication
for example, 25 to 35 kg is 2 tablets for strongyloidiasis (200 mcg/kg), while 26 to 44 kg is 2 tablets for onchocerciasis (150 mcg/kg).
For scabies, CDC recommends treating all household members and close contacts at the same time, washing bedding and clothing used in the 3 days before treatment in hot water with a hot dryer cycle, and sealing non-washable items in a plastic bag for several days to a week. For head lice, CDC recommends treating infested people and anyone who shares their bed. Pets do not spread human scabies or head lice.
Ask about residence or travel in Loa loa-endemic areas of West or Central Africa. People heavily infected with Loa loa may develop serious or even fatal encephalopathy after ivermectin, so the FDA label calls for pretreatment assessment after significant exposure. CDC refugee guidance uses a thick and thin blood smear collected between 10 a.m. and 2 p.m.
After onchocerciasis treatment, itching, rash, fever, joint pain, and lymph node swelling are common in the first 4 days as microfilariae die (FDA label). The label reports antihistamines and/or aspirin for most mild to moderate cases, and fluids, lying down, IV saline, and/or corticosteroids for postural hypotension. These reactions are not expected after strongyloidiasis treatment.
Screen for possible Loa loa exposure before ivermectin because high microfilarial loads increase the risk of serious neurologic adverse events.
Frequently asked questions about Ivermectin
It depends on the indication. FDA-labeled tablet regimens direct taking ivermectin on an empty stomach with water, while CDC scabies guidance recommends taking oral ivermectin with food to increase bioavailability. Follow the exact instruction in the prescribed treatment plan.
Scabies itching comes from an allergic reaction to the mites, so it can continue for several weeks even after all mites and eggs are killed. CDC advises reassessment if itching is still present 2 to 4 weeks after treatment or if new burrows or rash appear.
For classic scabies, CDC recommends two oral doses taken 7 to 14 days apart. When oral ivermectin is used off-label for head lice, CDC describes a repeat dose 9 to 10 days later. For strongyloidiasis, one dose is usually enough, but follow-up stool tests are needed to confirm the infection has cleared.
For scabies, CDC recommends treating all household members and close contacts at the same time. For head lice, CDC recommends treating only people with active lice and anyone who shares their bed. Pets do not spread human scabies or head lice.
A Mazzotti reaction is itching, rash, fever, swollen lymph nodes, or dizziness on standing that can occur after treatment for onchocerciasis (river blindness), as microfilariae die. The FDA label reports these reactions mainly in the first 4 days. They are not expected after treatment for strongyloidiasis. Call your clinician if your child develops these symptoms.
Children under 15 kg and pregnant caregivers usually need different treatments. CDC notes the safety of ivermectin has not been established in children weighing less than 15 kg or in pregnant women. Tell your healthcare team who else lives in the home so they can plan safe treatment for everyone. Newer scabies trials have studied younger children: a 2024 Lao PDR trial gave 100 children aged 2 to 4 years (10 to 14 kg) a 3 mg dose, repeated on day 14; 90 of 99 were clear by day 14 and side effects were mild (Gwee et al., Lancet Regional Health Western Pacific 2024). A multicenter trial in children weighing 5 to under 15 kg (NCT04332068, presented in 2025) reported that ivermectin was well tolerated. The FDA label and CDC guidance have not changed, so any use below 15 kg is off-label and must be directed by the prescriber (ideally with pediatric infectious disease input).
Drowsiness is uncommon: in FDA label strongyloidiasis trials, sleepiness was reported in under 1 in 100 patients and dizziness in under 3 in 100. For scabies, CDC says children can return to childcare or school the day after treatment.
No. Ivermectin is not authorized or approved by the FDA for preventing or treating COVID-19. Never give ivermectin products made for animals; they are formulated for large animals and can be dangerous for people. Even where state law lets pharmacies sell ivermectin without a prescription, the dose still has to be based on weight, and a clinician should check for Loa loa risk and drug interactions.
Sources reviewed for Ivermectin
https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=681888c9-af79-4b7d-ae80-c3f4f6f1effd
https://www.cdc.gov/strongyloides/hcp/clinical-care/index.html
https://www.who.int/news-room/fact-sheets/detail/onchocerciasis
https://www.cdc.gov/scabies/hcp/clinical-care/index.html
https://www.cdc.gov/scabies/prevention/index.html
https://www.cdc.gov/scabies/treatment/index.html