Malathion is a prescription lotion used for treating head lice in people 6 years and older. You massage just enough medication into dry hair so that the hair and scalp becomes wet. Leave malathion in and allow it to dry naturally. This process typically takes about 8 to 12 hours, which is much longer than other head lice treatments. Side effects of malathion include irritation to the skin and scalp.
Head lice
Malathion is an antiparasitic medication. It works by blocking an important protein, called cholinesterase, from working in lice. This causes death in live lice (and sometimes also in their eggs) because their nervous system no longer works properly.
Source: DailyMed
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Rare
Skin rash
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
Abdominal or stomach cramps
anxiety or restlessness
clumsiness or unsteadiness
confusion or mental depression
convulsions (seizures)
difficult or labored breathing
dizziness
drowsiness
increased sweating
increased watering of the mouth or eyes
loss of bowel or bladder control
muscle twitching of the eyelids, face, and neck
pinpoint pupils
slow heartbeat
trembling
unusual weakness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Works well for treating head lice
Might kill some nits (lice eggs)
Available as a lower-cost generic
Need to leave in hair for up to 12 hours, longer than other head lice treatments
Shouldn't be used on children younger than 6 years old
Might require a second treatment
Can cause eye irritation if you get it in your eyes
Apply and gently rub in malathion into your dry hair and scalp. Apply just enough medication to wet your hair and scalp. Leave malathion in and allow it to naturally dry for 8 to 12 hours.
While you're waiting for malathion to dry, don't expose your hair to heat or any open flames, because the medication is flammable (it can catch on fire).
After the malathion in your hair has dried, wash your hair with regular shampoo. Then, use a nit comb to remove any dead lice and eggs. Check for live lice every few days for 2-3 weeks to make sure they're gone.
You might experience a stinging sensation on your head when using malathion. This should go away, but if it doesn't you should contact your healthcare provider.
Don't apply more malathion than what's recommended. Doing so might cause the lotion to flow and fall onto other areas of your skin and body. This can lead to serious side effects, such as burns or eye irritations.
You can re-apply malathion in 7 to 9 days if you still have lice.
Wash and dry contaminated clothes, hats, bedding, and towels that you've been in contact with up to 2 days before treatment.
Let your provider know if you're breastfeeding, since it isn't known if malathion can get into your milk and harm your baby.
Avoid getting malathion into your eyes because it can cause irritation. Wash your hands after applying malathion.
Store malathion in a cool dark place at room temperature.
Malathion can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Malathion is flammable, meaning it can easily catch on fire. After applying malathion, don't smoke, stand near open flames, or use hair dryers and electric curlers. Make sure your hair naturally dries, and leave it uncovered.
Avoid getting malathion in your eyes because this medication can cause your eyes to become red and irritated. If your eyes are exposed, flush your eyes with water right away. Let your healthcare provider know if your eye still remains irritated or if you notice vision changes.
Malathion can irritate your skin. Wash off malathion, and wait for it to clear. Once cleared, you can try applying malathion again. However, if irritation happens again, stop the medication and talk to your healthcare provider.
Some people have experienced stinging or burning sensation, including second-degree burns, on skin that's been exposed to malathion. To lower you risk, don't use malathion more than what your healthcare provider recommended. If you're still having lice problems, talk to your healthcare provider before using more.
Dosage | Quantity | Price as low as | Price per unit |
---|---|---|---|
59ml of 0.5% | 1 bottle | $76.35 | $76.35 |
Apply malathion on dry hair just enough to wet the hair and scalp, including the back of your head and neck. Allow your hair to naturally dry (don't use an electric dryer), uncovered.
After 8 to 12 hours, shampoo and wash your hair. Use a fine-toothed nit comb to remove any dead lice and eggs from your hair. If lice are still present after 7 to 9 days, you can repeat.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Babies and infants
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Centers for Disease Control and Prevention. (2020). Malathion frequently asked questions.
Centers for Disease Control and Prevention. (2020). Treatment frequently asked questions.
PubChem. (n.d.). Malathion. National Library of Medicine.
Suven Pharmaceuticals Limited. (2022). Malathion lotion [package insert]. DailyMed.
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