What is Ivermectin: Uses, Warnings & Interactions

Updated Apr 18, 2024  •  Published Dec 30, 2020

Ivermectin overview

BRAND NAMES:

  • Stromectol, Soolantra, Sklice

Generic Names:

  • Ivermectin

Uses:

  • Treats infections caused by roundworms (nematodes) and lice. It also treats acne rosacea.

Therapeutic Classes:

  • Anthelmintic, antiparasitic, ectoparasiticide, scabicide, avermectin

Forms:

  • Tablet, cream, lotion

How it’s taken:

  • By mouth or topically

What is Ivermectin used for?

Healthcare professionals primarily use ivermectin to eradicate worm infestations, including roundworm infestations in the intestines (strongyloidiasis) or the eyes (onchocerciasis). However, prescription ivermectin cream is FDA-approved to treat acne rosacea. Over-the-counter ivermectin lotion is FDA-approved to treat lice infections (pediculosis), but some people use it off-label to treat mite infestations of the skin (scabies).

What form(s) does Ivermectin come in

  • Tablet (Rx)

    • 3 mg

  • Cream (Rx)

    • 1% (10 mg/gram)

  • Lotion (OTC)

    • 0.5% (5 mg/gram)

What are common Ivermectin doses?

  • For roundworm infestation of the intestines (strongyloidiasis): One dose that will provide 0.2 mg of ivermectin per kilogram of body weight (1 or more tablets)

  • For roundworm infestation of the eyes and skin (onchocerciasis): One dose that will provide 0.2 mg of ivermectin per kilogram of body weight (1 or more tablets)

  • For inflammatory lesions of rosacea: Apply as a thin layer to the affected skin areas on the face daily

RELATED: Ivermectin dosage, forms, and strengths

Common Ivermectin prescriptions

  • Ivermectin
    3mg tablet

  • Ivermectin
    117gm of 0.5% tube

  • Ivermectin
    45gm of 1% tube

  • Ivermectin
    45gm of 1% tube of cream

  • Ivermectin
    117gm of 0.5% tube of lotion

How to take Ivermectin

  • Follow all the healthcare provider’s instructions when taking this medicine.

  • How to take ivermectin tablets

    • For worm infestations, you will typically take only one dose.

    • A healthcare professional may give you the dose in a clinic or hospital.

    • If given a prescription, take the dose as soon as you can.

    • The healthcare provider will tell you how many tablets to take, and the pharmacy will give you only the prescribed number of tablets. 

    • Take ivermectin tablets on an empty stomach with a full glass (8 ounces) of water.

  • How to apply ivermectin cream

    • Apply ivermectin cream to the affected areas of the face once daily.

    • Do not put ivermectin cream on your lips or in your mouth, eyes, or vagina. 

    • Use a pea-sized dollop for each affected area.

    • Spread the cream in a thin layer over the affected area.

  • How to apply ivermectin lotion (OTC)

    • Ivermectin lotion is FDA-approved only to treat scalp lice.

    • Do not use ivermectin lotion in children younger than six months old

    • Do not get ivermectin lotion near the eyes or in the ears, nose, or mouth

    • When ready to apply the medicine, make sure the scalp hair is dry

    • When applying the lotion to the hair, keep your eyes tightly closed and covered with a washcloth or towel

    • Completely cover the scalp with the lotion and then apply the remaining lotion to all parts of the scalp hair

    • Rub the lotion into the hair

    • Use as much lotion as needed to cover the scalp and the hair completely

    • Using a timer or clock, allow the lotion to sit in the hair for 10 minutes

    • After 10 minutes, rinse the lotion out of the hair with water

    • Dry the hair

    • Wash your hands immediately

    • Throw away any unused lotion

    • You do not need to comb out the nits

    • Do not shampoo the hair for 24 hours after the treatment

    • Do not apply a second time unless instructed to by a healthcare provider

What to do if you miss a dose of Ivermectin

  • People will only take a single dose of ivermectin tablets. The single dose can be taken anytime but should be taken as soon as possible.

  • Ivermectin cream is applied once daily to the face, so a missed dose can be applied to the skin when remembered. If it’s the next day, do not apply the missed dose. Instead, apply that day’s dose to the skin. 

  • Ivermectin lotion is a one-dose treatment. It can be applied to the hair at any time. Do not apply ivermectin lotion a second time except under the advice of a healthcare professional.

Ivermectin contraindications

  • You should not use this medicine if you have had an allergic reaction to ivermectin.

  • Do not use ivermectin lotion in children younger than 6 months of age.

  • Do not allow children 6–12 years old to use ivermectin lotion except under the supervision of an adult.

Ivermectin warnings

  • Tell any doctor or other healthcare provider who treats you that you are using this medicine.

  • Tell your doctor if you are pregnant or breastfeeding.

  • This medicine may cause the following problems: 

    • Severe allergic reactions due to the death of parasites (tablets)

    • Neurological effects such as confusion, disorientation, or coma

  • Ivermectin tablets may make you dizzy or drowsy, but this is an uncommon side effect. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

  • Do not get the medicine in your eyes when using ivermectin cream or lotion. If you do, immediately flush the eyes with water.

  • Do not allow ivermectin cream or lotion to get on your lips or in your mouth, ears, nose, or vagina.

  • If you are taking ivermectin tablets for an intestinal infestation, you will need to have your bowel movements tested after treatment to ensure the infection is gone. Keep all appointments so these tests are done as often as the doctor needs.

  • If you take ivermectin tablets for river blindness (onchocerciasis), you may need retreatment and surgery to kill the adult parasite. You will need to see your healthcare provider for follow-up care.

  • People with HIV infections or weakened immune systems may need more than one treatment with ivermectin tablets.

  • Call your healthcare provider if your symptoms do not improve or if they get worse.

  • Do not use OTC ivermectin lotion a second time. Talk to a healthcare professional if the first application does not eradicate the lice infestation.

Ivermectin interactions

  • Before taking or using ivermectin, tell the healthcare provider about all the prescription drugs, over-the-counter medications, vitamins, and supplements you’re taking. Some drugs may interfere with the body’s ability to break down ivermectin.

  • When ivermectin is taken with the blood thinner warfarin, it may increase the risk of bleeding.

Ivermectin side effects

Serious side effects

Talk to a healthcare provider if you notice any signs or symptoms of a possible serious side effect including:

  • Racing heartbeats

  • Seizures

  • Mental alterations like confusion, disorientation, or sleepiness

  • Eye or eyelid irritation, pain, redness, swelling, or vision changes

  • Severe itching, rash, or hives

  • Persistent burning or irritation on the scalp (ivermectin lotion)

  • Blistering, peeling, red skin rash

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

Less Serious Side Effects

  • Dizziness

  • Mild rash or itching

  • Skin irritation or burning (cream)

  • Scalp irritation or burning (lotion)

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