Moxidectin
Moxidectin is a prescription medication that's used to treat a parasitic infection called onchocerciasis (also known as river blindness) in people 12 years and older. It works by paralyzing the Onchocerca volvulus worms that are causing the infection and preventing new worms from being made. This medication is a tablet that's taken by mouth, and complete treatment is 4 tablets taken as one dose. Some common side effects of moxidectin include itching, muscle pain, headache, and fast heart rate.
What is Moxidectin?
What is Moxidectin used for?
- Treatment of river blindness (onchocerciasis)
How Moxidectin works
Moxidectin is an antiparasitic medication that treats infections caused by the parasitic worms Onchocerca volvulus. The exact way that moxidectin works isn't known. But it’s thought to kill the worms by paralyzing them. Moxidectin also works by affecting the fertility of male and female worms, which lowers the amount of new worms that are produced.
Drug facts
Side effects of Moxidectin
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Itching (65%)
- Muscle or joint pain (64%)
- Headache (58%)
- Fast heart rate (39%)
- Rash (37%)
- Belly pain (31%)
- Changes in body temperature (27%)
- Flu-like symptoms (sore throat, congestion; 23%)
- Cough (17%)
- Diarrhea (15%)
Less Common Side Effects
- Dizziness
- Swelling
- Eye pain
- Itchy eye
- Swollen eyelid
- Eye discomfort
- Eye redness
- Watery eye
- Changes in vision
- High levels of eosinophils (white blood cells)
Moxidectin serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Serious allergic reaction: headache; fever; chills; dizziness; weakness; hives; itching; swollen arms or legs; swollen lymph nodes; joint or muscle pain; feeling of pins and needles; eye pain; itchy, watery, or red eyes; swollen eyelid; blurry vision; sensitivity to light
- Encephalopathy (brain damage): confusion, memory loss, personality change, can't concentrate, tiredness, loss of consciousness
Pros and cons of Moxidectin
Pros
- Only need to take one dose to treat for river blindness
- Can take with or without food
- Safe to take if you have mild-to-moderate kidney problems
Cons
- Need to take 4 tablets all at the same time for a complete treatment
- Can cause flu-like symptoms during the first week after treatment
- Not the treatment of choice for river blindness
Pharmacist tips for Moxidectin
- Take moxidectin with or without food. Take the medication as soon as possible after you get it from your provider. The tablets are good for up to 24 hours after it's been dispensed from its original container.
- Moxidectin comes as 2 mg tablets, so you'll need to take four tablets at the same time for complete treatment (8 mg).
- It's common to have flu-like symptoms in the first week after you take moxidectin. Watch out for symptoms such as weakness, muscle pain, headache, fast heart rate, dizziness, and itching. Let your provider know if these symptoms get worse or don't go away after a week.
- Moxidectin can make you feel dizzy or lightheaded when you're moving from a sitting or lying position to standing. Make sure to lie down until you feel better. Don't drive a car or operate machinery until you know how moxidectin affects you.
- Follow up with your provider after you take moxidectin to check whether you're fully treated. Even though this medication can damage and slow down the infection, it might not kill adult worms.
- Moxidectin can put you at higher risk of brain problems if you're infected with both river blindness and African eye worm. Get medical attention right away if you feel confused or tired or if you have memory loss or changes in personality.
- Keep moxidectin in its original container to protect it from light.
Common questions about Moxidectin
Moxidectin works by killing the larvae of the parasitic worms that cause river blindness. These worms are in their early stage of life and haven't reached adulthood yet. Keep in mind that moxidectin doesn't kill the adult worms. For this reason, it's important to follow up with your provider after you take moxidectin for treatment. Your provider can help you determine whether you need more treatment or whether your infection has been completely cleared.
Ivermectin (Stromectol) and moxidectin are both antiparasitic medications that are used to treat river blindness. They're both available by prescription from your provider; both have lower-cost generics available as well. According to the CDC, ivermectin (Stromectol) is the current treatment of choice for river blindness. But some studies showed that moxidectin might work better to slow down the spread of the infection. Talk to your provider to see which medication is right for you.
Yes, humans can take moxidectin tablets. It's FDA approved to treat river blindness in humans. This means that the medication works well and is safe to use for this purpose. Don't confuse moxidectin tablets for humans with over-the-counter products that contain the same ingredient (moxidectin); they're not the same. These over-the-counter products are for animals as a dewormer, are sold in pet stores or animal clinics, and can be harmful if you take them.
Typically, one dose of moxidectin is enough to treat a case of river blindness. One dose consists of four 2 mg tablets of moxidectin. In a clinical study, 83% of people who took a single dose of moxidectin had undetectable worm eggs in the skin 1 month after they completed treatment. Follow up with your provider if you're still having symptoms of river blindness after taking moxidectin to see whether you need another treatment or a different medication.
Breastfeeding isn't recommended when you take moxidectin and for 7 days after your treatment. Talk to your provider about possible alternatives, such as pumping and discarding your breast milk for a week, using previously stored breast milk, or using formula. This is because moxidectin might get into breast milk. We don't know what effects this has on breastfed babies, but animal studies suggest that harmful and potentially fatal side effects like weight loss are possible if babies are fed breast milk with moxidectin in it. While what happens in animal studies might not always happen to humans, it's best to be cautious. Please talk with your provider if you have any questions.
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Risks and warnings for Moxidectin
Moxidectin 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.
Allergic reactions
- Risk factors: First week after treatment | Severe infection
Moxidectin can cause allergic reactions called Mazzotti reactions, which can affect the skin, eyes, and other parts of your body. These reactions can include itching, rash, hives, headache, fever, dizziness, fast heartbeat, swollen arms or legs, joint or muscle pain, chills, and feeling of pins and needles. They can also cause eye pain, itchy or watery eyes, swollen eyelids, blurry vision, and sensitivity to light. The reactions usually start and go away within the first week of taking moxidectin.
Contact your provider right away if you experience any symptoms of an allergic or Mazzotti reaction. For mild-to-moderate allergic reactions, your provider might recommend that you take antihistamines or pain medications to relieve your symptoms. But for more severe allergic reactions, your provider might tell you to go to a hospital for more appropriate care.
Sudden drop in blood pressure
- Risk factor: Two days after treatment with moxidectin
Moxidectin can suddenly drop your blood pressure, especially when you stand after lying or sitting down. This can make you dizzy, which can also raise your risk for falls. This sudden drop in blood pressure most commonly happens during the first 2 days after you take moxidectin.
Don't drive a car or operate machinery until you know how moxidectin affects you. Make sure to hold onto something for support as you stand from a lying or sitting position. If you feel dizzy or lightheaded after you take moxidectin, lie down and rest until the symptoms go away. Let your provider know if your symptoms don't go away after a while.
Brain problems in people also infected with African eye worm
People who are infected with both river blindness and African eye worm are at higher risk of a life-threatening brain condition called encephalopathy after they take moxidectin. This condition can cause memory loss, drowsiness, personality changes, and confusion. In severe cases, it can lead to brain damage and death.
Before taking moxidectin, let your provider know if you think you've been exposed to African eye worm (this infection is caused by a parasitic worm that gets passed to humans through deerfly bites). Watch out for itchy swelling in any part of your body, which is a typical symptom of this infection. Your provider can test you to screen for African eye worm.
Swelling in certain people with severe river blindness
- Risk factors: A severe form of river blindness called hyper-reactive onchodermatitis (sowda)
People who have a severe form of river blindness (called sowda) might be more likely to have severe swelling, especially in the arms and legs, after they take moxidectin. Let your provider know if you notice any swelling anywhere in your body since you might need other treatment.
Moxidectin dosage
Typical dosage for Moxidectin
- Adults and children 12 years and older: The typical dose is 8 mg (four 2 mg tablets) by mouth for one dose only.
