The short line
Ivermectin online is the generic oral tablet. Stromectol is the brand name of that tablet. A valid prescription is required. A licensed healthcare provider decides whether it is appropriate.
The oral tablet
The tablet is a prescription medicine for worm parasites, called an anthelmintic. Helminths are that specific kind of worm. It treats infections those parasites cause, such as infections from roundworms.
It is made as a 3 mg oral tablet and a 6 mg oral tablet. It paralyzes the nerves and muscles of the parasite. That paralysis weakens the parasite or kills it.
Generic tablets may be made by different companies, so size, color, and shape may vary. The active ingredient is the same.
Ivermectin is used in humans and in animals, but the forms and the doses are different. Tablets sold as Stromectol are described as treatment for parasitic infections in humans and in animals. Only the human product should be used, and only as a healthcare professional directs. Animal versions are typically much stronger. A person should never take them. Taking an animal version can cause overdose and can be dangerous or life-threatening.
A topical cream and a topical lotion are other human forms, and they are not substitutes for this tablet. The cream is used for rosacea and the lotion for head lice. The form can change what the medication treats. Topical ivermectin should not be swallowed. The head-lice lotion can be nonprescription.
A compounded capsule may be made when a commercially available product does not meet a patient’s clinical needs. That capsule is not this tablet.
Approved infections
The approved uses are two parasitic infections: strongyloidiasis and onchocerciasis, also called river blindness. The tablet is primarily prescribed for those two. A doctor may also prescribe it for scabies or head lice after a proper diagnosis.
Strongyloidiasis
Strongyloidiasis is an intestinal infection caused by a roundworm. It affects the gut. The dose is 200 micrograms per kilogram of body weight, taken by mouth as one dose, charted on the 3 mg oral tablet.
Onchocerciasis
Onchocerciasis affects the skin and the eyes. The dose is 150 micrograms per kilogram of body weight, taken by mouth as one dose, charted on the 3 mg oral tablet. That dose is repeated every 3 to 12 months until the infection is clear.
Scabies
For scabies, the tablet begins killing the mites soon after the dose. Itching can continue for a few weeks after the mites are dead, because the itching is an allergic reaction to the mites and their waste. A doctor may recommend a second dose about two weeks after the first.
The tablet is not approved for viral infections. It will not treat colds, the flu, or infections caused by bacteria or viruses. It should not be used to prevent or treat COVID-19. It is not effective for that use: it does not help treat the infection or relieve symptoms. An FDA warning says it should not be used to treat COVID-19 in humans and is dangerous in large doses.
How the dose is set
A healthcare provider sets the dose from body weight, the type of parasitic infection, and overall health.
There is no single number of 3 mg tablets for everyone. The prescriber says how many tablets to take and when. Take exactly the amount prescribed. There is no one safe level for everyone, because the safest dose depends on the reason it is being used. At normal doses it is considered safe for humans. Taking too much raises the risk of side effects or overdose.
For most conditions it is given as a single oral dose. Many tablets are usually taken at the same time, sometimes five or more.
Children
For children, FDA approval covers certain parasitic conditions when the child weighs at least 15 kilograms, about 33 pounds. A pediatrician must set the dose. It should not be given without a prescription and direct guidance. The care team should be asked about use in children. Special care may be needed.
Pregnancy, breastfeeding, and warfarin
Before starting, tell the prescriber about every prescription drug, over-the-counter medicine, and herbal supplement.
Pregnancy
The tablets are generally not recommended during pregnancy, and they are avoided if a person is pregnant. There is not enough research to confirm safety for the unborn baby. Animal studies have shown birth defects, such as cleft palate, when ivermectin is consumed at high doses. A pregnant person, or someone planning pregnancy, needs the risks and benefits discussed with the doctor.
Breastfeeding
Oral ivermectin appears in human milk.
Warfarin
Warfarin (Coumadin, Jantoven) and other medicines that treat or prevent blood clots matter with this tablet. Ivermectin can make the blood thinner, which can raise the risk of bleeding.
Effects of a dose
Some effects usually do not need medical attention unless they continue or are bothersome: diarrhea, dizziness, fatigue, nausea, stomach pain, vomiting, tremors or shaking, itchiness, and skin rash.
Signs to report
Report these to the care team as soon as possible: allergic reactions (skin rash, itching, hives, swelling of the face, lips, tongue, or throat); a change in vision; dizziness, loss of balance or coordination, confusion, or trouble speaking; pain, tingling, or numbness in the hands or feet; muscle weakness; trouble walking; and seizures.
Rare but serious effects
Rare but serious effects of the tablets include fever, orthostatic hypotension (low blood pressure after standing up), seizures, and neurotoxicity (confusion and disorientation). Severe skin reactions are among them, including Stevens-Johnson syndrome and toxic epidermal necrolysis.
Mazzotti reaction
In onchocerciasis, a Mazzotti reaction is an inflammatory response to a large number of dying parasites, not to the drug itself. Symptoms can include fever, headache, rash, itching, and swollen lymph nodes. It typically signals that the medication is working. The doctor can help manage the symptoms.
Overdose
Overdose signs include rash, swelling (edema), headache, dizziness, weakness, nausea, vomiting, and diarrhea. More severe signs are seizures, difficulty breathing, and coma. Seek emergency medical attention immediately.
Food, missed doses, and alcohol
Take the tablet as directed on the prescription label, and according to the doctor or pharmacist. Take it at the same time every day. Take all of it unless the care team says to stop early. Keep taking it even if you think you are better.
Empty stomach
Take it by mouth with water, on an empty stomach, at least 30 minutes before food and 2 hours after food.
Water before a meal
Take it with a full glass of water at least one hour before a meal, so that it is properly absorbed.
A missed dose
A missed dose is uncommon. If the schedule has more than one dose and one is missed, contact the doctor. Do not take a double dose to make up for it.
Alcohol
Dizziness and lightheadedness are possible, and alcohol can worsen them. Avoid or limit alcohol on the day of the dose.
Half-life and excretion
The half-life is about 18 hours, the time for half of the drug to leave the bloodstream. Several half-lives are needed before the drug is fully cleared. Most of the drug and its byproducts are gone within a few days. It is primarily excreted through feces. Individual metabolism can affect this duration.
Keeping the tablets
Keep the tablets at room temperature, typically below 86°F (30°C), in the original container, tightly closed. Keep them away from moisture, heat, and direct light. Do not keep them in the bathroom, where humidity is high. Keep them out of the reach of children and pets.