Impavido (Miltefosine) – Oral

Warning:

The Food and Drug Administration (FDA) has assigned black box warnings to Impavido (miltefosine). Impavido isn't recommended during pregnancy because of the medication's potential to harm the unborn fetus. Before starting Impavido in people assigned female at birth and who are of childbearing age, pregnancy must be ruled out. During treatment and five months after your last Impavido dose, you'll need to use an effective form of contraception (birth control).

What Is Impavido?

Impavido (miltefosine) is a prescription medication option used to treat leishmaniasis infections from protozoan parasites. Protozoa are one-celled organisms (living things) from the animal kingdom.

Impavido is an antiparasitic—specifically, it's an antileishmanial drug. It's unknown how Impavido exactly works. However, Impavido is thought to cause protozoan cell death. It might do this by interacting with lipids (fatty substances), including the lipids on the protozoan cell surfaces.

Impavido might also block cytochrome c oxidase (CCO), an essential protein in the protozoan's mitochondria. Mitochondria generate energy. Blocking CCO may impair the mitochondria's ability to function and make energy necessary for the protozoan to carry out its normal living functions.

Impavido is available in a capsule dosage form.

Drug Facts

Generic Name: Miltefosine

Brand Name(s): Impavido

Drug Availability: Prescription

Therapeutic Classification: Antileishmanial

Available Generically: No

Controlled Substance: No

Administration Route: Oral

Active Ingredient: Miltefosine

Dosage Form(s): Capsule

What is Impavido Used For?

Impavido is used to treat leishmaniasis infections from protozoan parasites, which are spread through sand flies. The three primary forms of leishmaniasis are:

  • Visceral leishmaniasis (VL): VL is also known as kala-azar. This infection can be life-threatening. In fact, it's fatal in more than 95% of cases if untreated. Symptoms may include irregular fever spells, anemia, and enlarged spleen and liver. Impavido is used to treat VL caused by Leishmania donovani amoeba.
  • Cutaneous leishmaniasis (CL): CL is the most common form of leishmaniasis. Symptoms of CL may include skin lesions and ulcers that can lead to permanent scars and disability. Impavido treats CL caused by the following protozoa: Leishmania braziliensis, Leishmania guyanensis, and Leishmania panamensis.
  • Mucosal or mucocutaneous leishmaniasis: This type of leishmaniasis can cause partial or complete damage to the moist inner lining of your nose, mouth, and throat. Impavido treats mucosal leishmaniasis caused by Leishmania braziliensis protozoa.

Leishmaniasis is considered to be a neglected tropical disease (NTD). It's usually found in the following tropical and subtropical parts of the world:

  • Africa
  • Asia
  • Central America
  • South America
  • Middle East
  • Southern Europe

Although it's possible to get this infection in the United States, it's highly unlikely to occur here. It's estimated that leishmaniasis might affect 30,000 to 200,000 people in the United States.

How to Take Impavido

Take one Impavido 50 milligram (mg) capsule by mouth two to three times daily with food for 28 days.

The number of times you take Impavido daily will depend on your weight. If you weigh between 66 and 96.8 pounds, you'll take Impavido twice daily. You'll take the medication three times daily if you weigh at least 99 pounds.

Swallow the whole Impavido capsule. Don't try to split, break, crush, chew, or dissolve the capsule.

Storage

When you receive Impavido, store it at room temperature (between 68 degrees and 77 degrees F)—with a short-term safety storage range of 59 to 86 degrees.

To be safe, store this drug in a locked cabinet or closet that's out of reach of children and pets.

If you plan to travel with Impavido, become familiar with your final destination's regulations. The U.S. Embassy or Consulate may be a helpful resource. In general, however, make sure to copy your Impavido prescription. If possible, keep your medication in its original container from your pharmacy with your name on the label. Talk to your pharmacist or healthcare provider if you have any questions about traveling with your medicine.

You can also ask your pharmacist or healthcare provider about the best ways to dispose of your medications. The FDA website is a potentially helpful resource for where and how to discard all unused and expired drugs. You can also find disposal boxes in your area.

How Long Does Impavido Take to Work?

How long Impavido takes to work depends on the form of leishmaniasis. Also, keep in mind the length of Impavido therapy is 28 days.


For visceral leishmaniasis, you might experience an initial cure at the end of Impavido therapy, which is 28 days. You'll be considered finally cured if you don't have any VL symptoms at your six-month follow-up visit.


For cutaneous leishmaniasis, you may notice an improvement in your symptoms two weeks after the end of your therapy. You'll be considered cured if your ulcers (open sores) are completely closed and healed six months after the end of your treatment.


For mucosal leishmaniasis, some people notice a complete improvement in symptoms 12 months after the end of therapy.

Off-Label Uses

Impavido has an off-label use for treating certain free-living amoeba brain infections. Free-living amoeba are protozoa.

Healthcare providers may use Impavido in combination with other medications to treat the following free-living amoeba infections:

Primary amebic meningoencephalitis (PAM): PAM is a rare and life-threatening brain infection caused by Naegleria fowleri protozoa. Naegleria fowleri is typically found in soil and warm fresh water. It can enter through the nose when you're swimming. Then, it can travel from the nose to your brain and destroy brain tissue.

Granulomatous amebic encephalitis (GAE): GAE is a rare and severe central nervous system infection (infection of the brain and spinal cord) caused by Acanthamoeba or Balamuthia mandrillaris amoeba. In general, only people with a weakened immune system (the body's defense mechanism) may get this infection.

Acanthamoeba and Balamuthia mandrillaris amoeba can be found in soil and dust. Acanthamoeba can also be found in fresh water, such as lakes and rivers. Both free-living amoeba can enter your body from a cut or wound. Balamuthia mandrillaris may also be inhaled into your lungs. Once inside your body, they use the bloodstream to travel to your brain.

What Are the Side Effects of Impavido?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Common side effects of Impavido include:

Severe Side Effects

Get medical help right away if you develop the following serious side effects:

  • Severe allergic reaction: If you have a severe allergic reaction to Impavido, you may experience symptoms of swelling, itchiness, rash, and breathing difficulties.
  • Stevens-Johnson syndrome (SJS): SJS is a rare and severe condition that can become an emergency. Common symptoms of SJS may include peeling and blistering skin. The skin can feel very painful and raw.
  • Digestive system effects: While diarrhea, nausea, and vomiting are common side effects of Impavido, they can become excessive and severe.
  • Kidney-related effects: Abnormal kidney-related labs might be normal with Impavido. However, if you're experiencing worsening kidney function, symptoms may include bloody or foamy urine (pee), puffy eyes that don't go away, and swollen ankles or feet.
  • Liver-related effects: Abnormal liver-related labs might be typical with Impavido. However, if you're experiencing worsening liver function, symptoms may include stomach pain in the upper right side, dark-colored urine, and yellowing of the eyes or skin.
  • Thrombocytopenia: Thrombocytopenia is a condition of low platelets, which blocks your ability to clot appropriately. As a result, you may have symptoms of abnormal bruising and bleeding.

Call 911 if your symptoms feel life-threatening.

Long-Term Side Effects

Possible long-term side effects with Impavido might include reproductive system effects. Impavido is linked to impaired fertility in female rats, but its impact on fertility in humans assigned female at birth is unknown.

Impavido may also negatively affect fertility in people assigned male at birth. In fact, Impavido may lead to the following:

  • Less ejaculation volume
  • Lower sperm count
  • Lower sperm concentration
  • Lower sperm mobility
  • Sperm with abnormal shapes or sizes

Except for sperm concentration, all the sperm-related features listed above improved after three to six months. The duration of Impavido's effects on the production (making) of sperm is unknown.

Report Side Effects

Impavido may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Impavido Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • For leishmaniasis:
      • Adults and children 12 years of age and older weighing 45 kg or more—50 mg three times a day, with food (breakfast, lunch, and dinner), taken for 28 days.
      • Adults and children 12 years of age and older weighing 30 to 44 kilograms (kg)—50 milligrams (mg) two times a day, with food (breakfast and dinner), taken for 28 days.
      • Children younger than 12 years of age—Use and dose must be determined by your doctor.

Modifications

The following modifications (changes) should be kept in mind when using Impavido:

Severe allergic reaction: Avoid using Impavido if you have a known allergy to it or its ingredients. Ask your pharmacist or healthcare provider for a complete list of the ingredients if you're unsure.

Pregnancy: There is limited information about Impavido's effects and safety on pregnant humans and their unborn fetuses. However, the FDA advises against using this drug based on fetal harm seen in animal studies.

If you have been exposed to Impavido during pregnancy, you are encouraged to enroll in the pregnancy exposure registry to monitor pregnancy outcomes of the drug. Do so by visiting Impavido's website or calling 866-588-5405. Talk to your healthcare provider if you plan to become pregnant or are pregnant.

People assigned female at birth who are of childbearing age: If you are assigned female at birth and are of childbearing age, have an effective form of contraception (birth control) during your Impavido treatment and for five months after your last dose.

Breastfeeding: Not enough is known about the effects and safety of Impavido in human breast milk or on nursing babies. Due to the possibility of adverse effects on the nursing baby, breastfeeding isn't recommended during Impavido treatment and for five months after therapy.

Talk with your healthcare provider if you plan to breastfeed. Your healthcare provider can discuss breastfeeding and other available ways to feed your baby.

Older adults over 65 years: Clinical studies haven't included a large enough number of people in this age group to detect whether they respond differently from younger adults.

Children: There is limited information about Impavido's effectiveness and safety in children younger than 12. This is because the medication hasn't been studied in children from this age group. However, due to information from an animal study, young children might be more sensitive to Impavido's side effects (e.g., eye and kidney effects) than adults.

Kidney or liver problems: Impavido hasn't been studied in people with kidney or liver impairment. Impavido, however, may cause abnormal kidney- or liver-related lab values. Therefore, your healthcare provider will regularly monitor your kidney and liver-related labs to prevent worsening kidney or liver function.

Digestive system effects: You may experience digestive system effects (e.g., vomiting or diarrhea) with Impavido. If you're assigned female at birth, use an additional contraceptive (birth control) option that isn't oral (by mouth), such as a condom. Also, ensure that you drink adequate fluids to stay hydrated and prevent kidney injury.

Missed Dose

Limited information is available on the next steps if you miss an Impavido dose.

The general recommendation for most medications is to take the dose as soon as you remember. If it's already close to your next scheduled dose, then skip the missed dose and take the following dose at your next scheduled dosing time. Don't try to double up to make up for the missed dose.

These directions, however, may vary from your healthcare provider's recommendations. Reach out to your prescribing provider. They'll be able to advise you on the next steps.

Try to find ways that work for you to help yourself remember to keep your appointments and take your medication routinely. Impavido might be less effective at treating your condition if you miss too many doses.

Overdose: What Happens If I Take Too Much Impavido?

The symptoms of a suspected overdose of Impavido may include:

  • Diarrhea
  • Stomach pain
  • Vomiting

If you think that you're experiencing an overdose or life-threatening symptoms, seek immediate medical attention.

What Happens If I Overdose on Impavido?

If you think you or someone else may have overdosed on Impavido, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Impavido, call 911 immediately.

Precautions

Drug Content Provided and Reviewed by IBM Micromedex®

It is very important that your doctor check your or your child's progress at regular visits. This will allow your to see if the medicine is working properly and to decide if you should continue to take it. Blood tests will be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant during treatment and for 5 months after the last dose of this medicine. If you think you have become pregnant while using this medicine, tell your doctor right away.

You must have a negative urine or blood pregnancy test before you will be allowed to take this medicine. If you miss a period while you are using this medicine, tell your doctor right away.

Vomiting or diarrhea may occur while taking this medicine. These side effects may prevent birth control pills from working properly. You may use other forms of birth control include condoms, diaphragms, or contraceptive foams or jellies.

Serious skin reactions can occur with this medicine. Check with your doctor right away if you or your child have blistering, peeling, or loose skin, red skin lesions, severe acne or skin rash, sores or ulcers on the skin, or fever or chills while you are using this medicine.

What Are Reasons I Shouldn’t Take Impavido?

Before taking Impavido, talk with your healthcare provider if any of the following applies to you:

  • Severe allergic reaction: If you have a severe allergic reaction to Impavido or its components (ingredients), this medication isn't a good option for you.
  • Pregnancy: The FDA warns against using Impavido in pregnancy based on findings in animal data, which showed fetal harm. If you have been exposed to this drug during pregnancy, consider enrolling in the pregnancy exposure registry by visiting Impavido's website or calling 866-588-5405. Talk with your healthcare provider if you plan to become pregnant or are pregnant.
  • Breastfeeding: There's no information about the effects and safety of Impavido on human breast milk and nursing infants. Due to the possibility of adverse effects on the nursing baby, breastfeeding isn't recommended during Impavido treatment and for five months after therapy.
  • Older adults over 65: Clinical studies have not included enough older adults to assess the effectiveness and safety differences between older and younger adults.
  • Children: There is limited information about Impavido's effectiveness and safety in children younger than 12. This medication hasn't been studied in children from this age group. Young children, however, might be more sensitive to Impavido's side effects (e.g., eye and kidney effects)—when compared to adults.
  • Sjӧgren-Larsson syndrome (SLS): Avoid Impavido if you have SLS. SLS is an inherited condition that blocks the body's ability to break down lipids (fatty substances) and make energy. Based on this information and how Impavido might work, taking Impavido may worsen this condition. Symptoms of SLS include dry, scaly skin, intellectual difficulties, speech troubles, and abnormal muscle stiffness.

What Other Medications Interact With Impavido?

Impavido doesn't interact with the liver protein cytochrome P450 (CYP450) which is responsible for breaking down medications. Specifically, Impavido doesn't inhibit (block) CYP450 proteins from doing their jobs. It also doesn't induce (encourage) these proteins to work faster.

It's also unknown whether Impavido interacts with proteins that transport (move) medications around in the body. Currently, Impavido appears to have no known medication interactions.

For questions or concerns about medication interactions with Impavido, talk with your pharmacist or healthcare provider.

And be sure to talk with your healthcare provider about any other medicines that you take or plan to take, including over-the-counter (nonprescription) products, vitamins, herbs, or plant-based medicines.

What Medications Are Similar?

In general, there are several available medications for leishmaniasis infections. Options may include the following dosage forms:

  • Intravenous (IV) injections or infusions into the vein
  • Intramuscular (IM) injections into the muscle
  • Intralesional (IL) injections into the lesion
  • Topical skin products
  • Oral (by mouth) pills

Impavido is an oral pill option. Other oral medications include antifungals—like ketoconazole and fluconazole. Experts, however, only recommend them as off-label treatment options for CL. Impavido, on the other hand, is a potential oral treatment option for all three forms of leishmaniasis.

Other treatment choices that have been used for all three forms of leishmaniasis include:

  • AmBisome (liposomal amphotericin B): AmBisome is an IV antifungal medication. While the FDA has only approved AmBisome for visceral leishmaniasis, experts recommend it as an off-label treatment option for other forms of leishmaniasis, too.
  • Fungizone (amphotericin B deoxycholate): Like AmBisome, Fungizone is an IV antifungal medication. It's used off-label for leishmaniasis. Compared to AmBisome, however, it tends to have more side effects.
  • Pentostam (sodium stibogluconate): Pentostam is an IV, IM, and IL antiprotozoal medication. It's thought to work by interfering with the protozoan's ability to make energy. However, the FDA hasn't approved this medication. It's only available in the United States as an investigational new drug (IND).
  • Pentam 300 (pentamidine isethionate): Pentam 300 is an IV and IM antiprotozoal medication that's used off-label for leishmaniasis. It works by inhibiting the protozoa production (making) of genetic material, protein, and phospholipids (fatty substances on the protozoa cell surfaces).

Compared to all of these medications, Impavido has the following possible advantages and disadvantages:

  • Impavido is available in the United States—like ketoconazole, fluconazole, AmBisome, Fungizone, and Pentam 300.
  • Impavido is available in a convenient oral dosage form—like ketoconazole and fluconazole.
  • Impavido is the only option approved by experts and the FDA to treat all three forms of leishmaniasis.
  • Impavido doesn't have a generic version yet. Ketoconazole, fluconazole, AmBisome, Fungizone, and Pentam 300 do have generics.
  • Impavido is leishmania specific.

For CL and mucosal leishmaniasis, there are no first-choice options. Experts recommend that treatment selection should be based on many factors, which may include:

  • Dominant leishmania growth in the area
  • Specific treatment response rates for the area
  • Age
  • Medical history
  • Side effects
  • Personal preferences

For VL, on the other hand, the first-choice treatment option is AmBisome. You may also see AmBisome used in people positive for human immunodeficiency virus (HIV) with leishmaniasis infections.

Frequently Asked Questions

  • Where is Impavido available?

    Local retail pharmacies don't usually keep Impavido in stock. However, if you need this medication, the pharmacy can order Impavido directly through the manufacturer's website.

  • How much does Impavido cost?

    Impavido isn't available in a generic version yet. The FDA also assigned Impavido an orphan drug (OD) status (granting companies tax incentives for performing clinical trials) for a few rare medical conditions. So, this medication might be costly.

    Impavido's manufacturer's website states that Impavido is covered by most insurance plans. If cost is a concern, talk to your healthcare provider or pharmacist about your options. You may be able to reduce costs from a savings program through the manufacturer’s website, as some manufacturers offer copay assistance to make their medication more affordable, or a patient assistance program.

  • Can I use Impavido to prevent leishmaniasis infections?

    No. Unfortunately, no current medications or vaccines can prevent leishmaniasis infections.

How Can I Stay Healthy While Taking Impavido?

If you're taking Impavido, leishmaniasis has likely affected your quality of life. Having a leishmaniasis infection does have its challenges. You may have tried different approaches or treatments. Refer below for some general tips to support your health.

Recommendations to prevent and control this infection include:

  • Take antileishmanial-related medications as recommended by your healthcare provider.
  • Take Impavido with food to limit digestive system effects.
  • Drink adequate amounts of water to prevent dehydration from Impavido's side effects. Staying hydrated will also prevent kidney injury.
  • Keep up with medical and lab appointments to prevent worsening kidney and liver problems.
  • Limit outdoor activities between dusk to dawn, when sand flies are most active.
  • Use an insect repellent.
  • Make sure that your place of residence is well-screened and air-conditioned.
  • Use bed nets, and make sure they are tucked under the bed. Consider soaking or spraying the bed net with pyrethroid-containing insecticide.
  • Consider spraying insecticide inside your place of residence to kill insects. The pyrethroid-containing insecticide can also be used on screens and curtains.
  • Cover up by wearing long-sleeved shirts, pants, and socks. Also, tuck your shirt into your pants.
  • Consider spraying the pyrethroid-containing insecticide on your clothes. After your clothes have been washed five times, you should respray your clothes.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Ross Phan, PharmD, BCACP, BCGP, BCPS
Ross is a writer for Verywell with years of experience practicing pharmacy in various settings. She is also a board-certified clinical pharmacist and the founder of Off Script Consults.