6 Emverm Side Effects and How to Manage Them

Viruses, bacteria, and infections are often mentioned in the same conversation. But there’s more to the story. Parasites are found all over the world, too, and infections from them are more common than you think. Parasitic infections affect millions of people all around the world, including in the U.S. Thankfully, they’re treatable.

Emverm (mebendazole) is one anti-parasitic medication. Adults and kids ages 2 years and older can take it for various worm (parasitic) infections. It’s FDA approved to treat gut infections caused by hookworm, roundworm, or whipworm. It can also treat a pinworm infection.

Emverm chewable tablets are a convenient, short-term treatment. Most people take it for just 1 to 3 days at a time, and side effects aren’t typically an issue. However, if you’re prescribed a higher dosage, or need to take it for a longer period of time, there’s a greater chance of side effects.

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Let’s review six notable Emverm side effects and how to manage them.

1. Appetite changes

Emverm has been linked to appetite changes — most commonly, a loss of appetite. But worm infections can also cause an upset stomach on their own. Feeling less hungry could be due to the medication, the infection, or a combination of the two. This should subside with time, regardless of cause.

In the meantime, do your best to continue eating while taking Emverm — even if you may not be hungry. Sticking to small portions, eating as often as tolerated, and drinking liquids between meals (not during) can help. Foods like smoothies, soup, and toast may also be easier to tolerate.

Make sure to listen to your body though. If you find that your symptoms are long-lasting or hard to deal with, contact your healthcare provider right away. You should also contact them if you’re losing more than 1 to 2 lbs per week.

2. Nausea, diarrhea, and stomach pain

Nausea and diarrhea are never pleasant side effects. But stomach-related symptoms like these can happen while taking Emverm. They could be due to the medication, infection, or both.

As your infection improves, these symptoms should also get better. But there are still ways for you to address the situation. It’s a good idea to take Emverm with food to lower your chances of an upset stomach. Avoiding dishes that could irritate your stomach, like spicy or fried foods, is another helpful measure. And avoiding large meals in favor of smaller, more frequent ones can keep your stomach at ease.

If any of these side effects persist or worsen, contact your healthcare provider for guidance. They may recommend an anti-nausea medicine like bismuth subsalicylate (Pepto-Bismol) or an anti-diarrhea medicine like loperamide (Imodium A-D). They may also make an adjustment to your treatment plan.

3. Skin rashes

Many medications can cause skin reactions, or what’s sometimes called “drug rashes,” as a side effect. Some are mild, and others are more serious. Emverm has been linked to serious rashes in specific situations.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are potentially life-threatening skin reactions that can occur when Emverm is taken in combination with metronidazole (Flagyl). Metronidazole is an antibiotic that treats bacterial and parasitic infections.

Thankfully, if you took metronidazole awhile back, this shouldn’t be an issue. The risk of developing SJS or TEN is more relevant to people who have taken metronidazole within the last 6 weeks. It’s also more likely with higher doses of metronidazole (more than 2,000 mg per day).

Go to the nearest emergency room right away if you have any possible symptoms of a serious skin reaction, such as swollen lips, blisters on your skin, or hives. This is important even if your symptoms feel relatively mild. SJS and TEN can become life-threatening if they’re not promptly addressed.

Good to know: Serious skin rashes are less likely to happen if you’re taking Emverm by itself — without metronidazole. Make sure to give your healthcare provider and pharmacist an updated list of all vitamins, over-the-counter, and prescription medications you take. This will help them watch for interactions.

4. Liver problems

Emverm has the potential to cause liver problems. The risk is rare, but it’s higher when Emverm is taken at higher doses or multiple times in a row. It usually happens within a few days of starting the medication and it should quickly resolve after you stop taking it.

These problems don’t usually cause symptoms, either. If your healthcare provider checks your lab work, they may just find high levels of alanine transaminase (ALT) and aspartate aminotransferase (AST). These are liver enzymes (proteins) that act as warning signs for liver health. If ALT/AST are raised, it may mean that liver damage is unfolding.

Again, you won’t be able to notice high ALT/AST levels on their own. But if you develop symptoms such as bloating, fever, or yellowing of the skin or eyes (jaundice), a liver issue may be at play.

If you develop symptoms of liver problems while taking Emverm, talk with your healthcare provider as soon as you can. They may tell you to stop taking Emverm. But it’s important to continue taking your medication until they tell you otherwise.

5. Seizures

There have been some reports of seizures among children younger than 12 months old. Emverm is only approved for people ages 2 years and older because of this risk.

Regardless of age, it’s important to be aware of the possible signs and symptoms of a seizure. Jerking movements, sudden stiffness, and unresponsiveness are all clues. Same goes for limpness and a staring, absent gaze.

If someone you know has a seizure after taking Emverm, lay them on the ground on their side and call 911 immediately. It’s important to talk with your healthcare provider if you have a history of seizures so they can discuss your options with you.

6. Low white blood cell count

White blood cells help your body fight infections. If you don’t have enough white blood cells (neutropenia), you’re more likely to get sick with a serious one. Neutropenia is a common side effect of medications such as chemotherapy, but other medications can cause it too.

Emverm is no exception. It can happen if you take higher doses of the medication or take it for longer periods of time. A usual length of treatment with Emverm is 3 days, but it can be longer for harder-to-treat infections.

As a precaution, your healthcare provider may monitor your blood work while you’re taking Emverm. This will help them to respond to any potential situations before they become urgent.

When to contact a healthcare provider about Emverm side

Nausea, diarrhea, and appetite changes are common Emverm side effects that can generally be managed at home. But if any side effects become bothersome or long lasting, it’s a good idea to contact your healthcare provider.

Other situations are more serious. If you develop any symptoms of liver damage, such as bloating, fever, or yellowing of the skin or eyes, let your provider know. And seek medical attention immediately if you develop a skin rash or have a seizure.

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Written by:

Hannah Elmore, PharmD Candidate

Hannah Elmore, a PharmD candidate, works as a clinical pharmacy intern with IU Health in Indianapolis. She has previously worked in community pharmacy locations, including CVS and Costco Wholesalers, with a total of 4 years of patient-centered pharmacy experience.

Edited by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

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