In the U.S.—

• Anthelmintic, oral-local

Niclosamide (ni-KLOE-sa-mide) belongs to the family of medicines called anthelmintics ( ant-hel-MIN-tiks) . Anthelmintics are medicines used in the treatment of worm infections.

Niclosamide is used to treat broad or fish tapeworm, dwarf tapeworm, and beef tapeworm infections. Niclosamide may also be used for other tapeworm infections as determined by your doctor. It will not work for other types of worm infections (for example, pinworms or roundworms).

Niclosamide works by killing tapeworms on contact. The killed worms are then passed in the stool. However, you may not notice them since they are sometimes destroyed in the intestine.

Niclosamide is available only with your doctor's prescription, in the following dosage form:

Oral
• Chewable tablets (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For niclosamide, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to niclosamide. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Niclosamide has not been studied in pregnant women. However, it has not been shown to cause birth defects or other problems in animal studies.

Breast-feeding—It is not known whether niclosamide passes into breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking this medicine should discuss this with their doctor.

Children—This medicine has been tested in a limited number of children 2 years of age or older and, in effective doses, has not been reported to cause different side effects or problems in children than it does in adults.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of niclosamide in the elderly with use in other age groups.

Other medicines—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 health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

No special preparations or additional steps (for example, special diets, fasting, other medicines, laxatives, or enemas) are necessary before, during, or immediately after taking niclosamide.

Niclosamide may be taken on an empty stomach (either 1 hour before or 2 hours after a meal). However, to prevent stomach upset, it is best taken after a light meal (for example, breakfast).

Niclosamide tablets should be thoroughly chewed or crushed and then swallowed with a small amount of water. If this medicine is being given to a young child, the tablets should be crushed to a fine powder and mixed with a small amount of water to form a paste.

For patients taking this medicine for beef tapeworms or broad or fish tapeworms:

• To help clear up your infection completely, take this medicine exactly as directed by your doctor. Usually one dose is enough. However, in some patients a second dose of this medicine may be required to clear up the infection completely.

For patients taking this medicine for dwarf tapeworms :

• To help clear up your infection completely, keep taking this medicine for the full time of treatment (usually 7 days) , even if your symptoms begin to clear up after a few days. In some patients, a second course of this medicine may be required to clear up the infection completely. If you stop taking this medicine too soon, your infection may return. Do not miss any doses. Some patients with tapeworm infections may not notice any symptoms or may have only mild symptoms.

Dosing—

The dose of niclosamide 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 niclosamide. If your dose is different, do not change it unless your doctor tells you to do so.

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 taking niclosamide.

• For oral dosage form (tablets):
  • For fish tapeworm or beef tapeworm:
    • Adults—2 grams as a single dose. Treatment may be repeated in seven days if needed.
    • Children—Dose is based on body weight and must be determined by your doctor.
      • For children weighing 11 to 34 kilograms (kg) (24.2 to 74.8 pounds): 1 gram as a single dose. Treatment may be repeated in seven days if needed.
      • For children weighing over 34 kg (74.8 pounds): 1.5 grams as a single dose. Treatment may be repeated in seven days if needed.
  • For dwarf tapeworm:
    • Adults—2 grams a day for seven days. Treatment may be repeated in seven to fourteen days if needed.
    • Children—Dose is based on body weight and must be determined by your doctor.
      • For children weighing 11 to 34 kg (24.2 to 74.8 pounds): 1 gram on the first day. Then 500 milligrams (mg) once a day for the next six days. Treatment may be repeated in seven to fourteen days if needed.
      • For children weighing over 34 kg (74.8 pounds): 1.5 grams on the first day. Then 1 gram once a day for the next six days. Treatment may be repeated in seven to fourteen days if needed.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

It is important that your doctor check your progress at regular visits. This is to make sure that the infection is cleared up completely.

If your symptoms do not improve within a few days, or if they become worse, check with your doctor.

Along with its needed effects, a medicine may cause some unwanted effects. The following side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• Less common
  • Abdominal or stomach cramps or pain;  diarrhea;  loss of appetite;  nausea or vomiting 
  
  

• Rare
  • Dizziness or lightheadedness;  drowsiness ;  itching of the rectal area;  skin rash;  unpleasant taste 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.