The 3 mg tablet treats two licensed infections. Grade the rest.

Which infections sit on the 3 mg label?

Oral ivermectin in the United States is a 3 mg tablet. The count is weight-based. The bottle is prescription. The file names two parasites and stops there.

Intestinal strongyloidiasis is the first listed use. The target is the gut stage of Strongyloides stercoralis, not a disseminated hyperinfection already in the lungs and bloodstream. The labeled dose is about 200 mcg per kg as one swallow, taken on an empty stomach with water.

Onchocerciasis is the second listed use. The labeled dose is about 150 mcg per kg, same empty-stomach rule. The molecule hits tissue microfilariae. The adult worms in nodules keep living. That is printed as a note, not a rumor.

Those two lines decide how a 3 mg strip is counted. For Strongyloides the label steps from one tablet at 15 to 24 kg up to five tablets at 66 to 79 kg. At 80 kg and above the prescriber calculates 200 mcg/kg. For river blindness the steps differ: one tablet at 15 to 25 kg, two at 26 to 44 kg, three at 45 to 64 kg, four at 65 to 84 kg. At 85 kg and above the count is 150 mcg/kg.

People mix the two tables because both use the same 3 mg tablet. They are not interchangeable. A river-blindness count under-doses Strongyloides. A Strongyloides count overshoots the oncho table. The infection on the order decides the arithmetic.

Do Soolantra and Sklice count as the same file?

They share the molecule. They do not share the 3 mg swallow or the worm indications. Treating them as 'more ivermectin uses' without naming the product is how people invent a tablet for rosacea.

Soolantra is ivermectin 1% cream for inflammatory lesions of rosacea. Apply a thin layer to affected face areas once daily. It is not for the mouth, the eye, or the vagina. FDA approved that cream on 19 December 2014 (NDA 206255).

Sklice is ivermectin 0.5% lotion for head lice in people 6 months and older. One application to dry hair and scalp. Leave it on, then rinse, as the lotion instructions say. That product later moved to over-the-counter sale. It is still not a 3 mg tablet.

Demodex and Pediculus are arthropods, so the same channel story that works on mites and lice is biologically tidy. The regulatory story is not tidy. A cream, a lotion, and a counted tablet are three products. Only the tablet carries Strongyloides and onchocerciasis.

Where does WHO put the tablet in filariasis rounds?

Lymphatic filariasis programmes do not treat the 3 mg strip as a solo drug. They pair it. Where onchocerciasis is co-endemic, the usual pair is ivermectin plus albendazole. Diethylcarbamazine is avoided there because it can trigger severe reactions in river-blindness infection.

Where onchocerciasis is absent, the older pair is diethylcarbamazine plus albendazole. In 2017 WHO added a triple option, ivermectin plus DEC plus albendazole (IDA), to speed microfilarial clearance in units that are not co-endemic for onchocerciasis or loiasis.

IDA is an alternative, not a patch for poor coverage. WHO still wants epidemiological coverage of at least 65% each round. A three-drug swallow does not fix a round that never reached the village.

This is population evidence. Annual or repeated rounds shrink the reservoir mosquitoes pick up. Established limb swelling does not reverse because a tablet killed circulating larvae. Limb care sits beside the drug, not inside it.

For a traveler or a single imported case, the 3 mg US label still does not list Wuchereria bancrofti. The programme grade is strong. The US tablet indication is not that disease.

Did the strongyloidiasis trials beat albendazole?

Yes, on the endpoint the label used. Cure meant no larvae in at least two stool checks 3 to 4 weeks after the dose. Across comparative and open studies, a single 200 mcg/kg dose cured 64 to 100% of evaluable patients.

Two international trials used albendazole 200 mg twice daily for 3 days as the comparator. Ivermectin at 170 to 200 mcg/kg once beat that course. Three other trials used thiabendazole 25 mg/kg twice daily for 3 days. A single 200 mcg/kg ivermectin day matched that older, harder-to-tolerate drug.

WHO's later strongyloidiasis guideline still treats those early stool-cure studies as the backbone: large effect, fast clearance, no plausible confounder that explains the gap. Most national lists now name ivermectin first for an individual Strongyloides case.

The label still wants follow-up stools. A quieter abdomen is not eradication. Strongyloides can autoinfect, so a missed larva restarts the loop. Extra doses are not routine on the US file. They become a clinical decision when stools stay positive or when the host is about to be immunosuppressed.

That last setting is where the licensed tablet earns its keep outside travel clinics. High-dose steroids, transplant drugs, or some chemotherapy can turn a silent gut infection into hyperinfection. Screening people with endemic exposure before that step, then giving the 200 mcg/kg count if needed, is prevention with a drug that already has a Strongyloides indication.

How should a reader grade each use?

Grade the indication, not the molecule's reputation. A Nobel Prize in 2015 for Satoshi Omura and William Campbell explains why river-blindness programmes exist. It does not move a COVID endpoint. It does not put scabies on STROMECTOL.

Call a use strong when a regulator listed it and a trial measured the parasite that matters. Stools for Strongyloides. Skin microfilariae for onchocerciasis. Lesion counts for the rosacea cream. Lice checks for the lotion.

Call a use good when CDC or WHO writes a dose and comparative data exist, even if the US tablet stayed silent. Classic scabies sits here. Filariasis combination rounds sit here.

Call a use absent when large randomized trials measured a clinical COVID outcome and did not beat placebo. That cut is the companion myth page, not a third licensed worm.

Why does river blindness need a repeated 150 mcg/kg count?

CDC clinical care for onchocerciasis calls ivermectin the treatment of choice because it kills microfilariae. It does not kill adult worms. One 150 mcg/kg swallow drops the skin load. The females in nodules keep shedding larvae for years.

The STROMECTOL studies behind that line enrolled 1278 patients. A double-blind, placebo-controlled adult study used one 150 mcg/kg swallow. Skin microfilariae (geometric mean) fell 83.2% by day 3 and 99.5% by month 3. A reduction greater than 90% held through 12 months.

An open pediatric study in 103 children aged 6 to 13 years, weighing 17 to 41 kg, showed the same pattern of skin-count drop for up to a year. That is why programmes can space a community round. It is also why one swallow is control, not a cure of the adult worm.

Mass campaigns most often repeat at 12 months. For a single patient the label allows retreatment as soon as 3 months. CDC writes 150 mcg/kg every 6 months as a common individual rhythm. Higher-than-labeled doses add harm without a proven extra kill of adults.

Doxycycline is a separate, non-standard add-on in some specialist notes because it targets Wolbachia inside the adult worm. That is not a substitute for the 150 mcg/kg microfilarial count. It is not on the ivermectin tablet label.

One regional trap sits next to this success. People with a heavy Loa loa load in parts of West or Central Africa can develop a serious, sometimes fatal encephalopathy after a microfilaricide. The label tells clinicians to assess loiasis risk before dosing anyone with that exposure.

Is oral ivermectin a licensed scabies drug in the United States?

No. The 3 mg tablet file does not list Sarcoptes scabiei. CDC still treats oral ivermectin as a drug of choice beside 5% permethrin. That is a guideline grade, not a US indication.

For classic scabies CDC writes two 200 mcg/kg doses, 7 to 14 days apart, taken with food. The food line matters. The tablet label says empty stomach for the worm indications. Scabies experts want a meal so more drug reaches skin.

The second dose exists because ivermectin is weak against eggs. Mites that hatch after the first swallow restart the itch if nobody comes back. Crusted scabies is a different schedule: oral drug plus a topical scabicide, with three, five, or seven 200 mcg/kg doses by severity.

Safety in children under 15 kg and in pregnancy is not established on the oral file. That is why many clinics still start with permethrin in those groups. Institutional outbreaks and people who cannot cream from neck to toes are the usual reasons the oral route gets used anyway.

Itch that lingers for a week or two after the mites die is expected. The rash is allergy to mite debris. Another scabicide in that window often inflames skin that was already clearing.

What the 3 mg tablet still does not treat

Tapeworms and flukes sit outside the glutamate-gated chloride story that makes nematodes and some arthropods drop. Do not borrow a Strongyloides count for a cyst in liver or brain. That job, when it is a job for a benzimidazole, is albendazole's US file, compared on the which-worm page.

Pinworm and the common soil worms are mebendazole's 100 mg chewable work. See how to take mebendazole 100 mg and the mebendazole monograph. Ivermectin is the wrong first pick there.

The 3 mg tablet treats what the trials and the label measured. Count it for those parasites. Send every other claim to its own page of evidence.