Niclosamide (Oral)

Niclosamide is a chewable tablet prescribed by doctors to treat some infestations of tapeworms and is tolerated well with minimal side effects.


What is Niclosamide?

Niclosamide is a single dose, chewable tablet that is prescribed by doctors to kill infestations of intestinal fluke and tapeworm species. Discovered in 1958 by scientists in Germany, Niclosamide is on the WHO list of essential medicines but is not commercially available in the US. During 2016, a screening study found the use of Niclosamide was effective against the Zika virus. The drug is also an inhibitor of the STAT3 nerve pathway, which some cancers use to reproduce. Uses for Niclosamide could include patients with colon cancer, breast cancer or prostate cancer.

How does Niclosamide work?

Niclosamide is considered to be an anthelmintic type of drug; a member of a group of medications that are antiparasitic used on infestations of internal parasites. Some medications in this group stun the parasites and others, like Niclosamide, kill them outright. The parasites are then passed harmlessly through the stool or destroyed in the intestinal tract.

Once taken, Niclosamide works almost immediately by disturbing a crucial pathway in the metabolic structure of the parasite and killing it completely. The drug itself is absorbed by the patient's body only in very small amounts and this keeps side effects to a minimum.

What are tapeworms?

Tapeworms are an intestinal parasite which can be passed through undercooked meat or water. There are six known types of tapeworms, which cause symptoms such as weak muscles, diarrhea, nausea, pain in the abdomen, loss of appetite, fatigue, weight loss and other symptoms. Some patients, however, don't experience any symptoms at all.

Conditions Treated

  • Tapeworm infection
  • Intestinal fluke infection
  • Beef tapeworm infection
  • Pork tapeworm infection
  • Fish tapeworm infection
  • Large intestinal fluke infection
  • Molluscicide
  • Schistosomiasis

Type Of Medicine

  • Antiparasitic
  • Antihelminthic

Side Effects

As Niclosamide works against killing an infestation of tapeworm or other parasites, it may cause adverse health effects in some patients. Typically these symptoms are relieved over time as the medication works through your system. Should they linger or become severe, report them to your physician immediately:

  • Pain or cramps in stomach or abdomen
  • Diarrhea
  • Appetite loss
  • Vomiting
  • Nausea
  • Dizzy, lightheaded
  • Drowsy, sleepy
  • Rectal itching
  • Rash on skin
  • Foul taste in mouth

Some patients may experience other symptoms that aren't listed here. If you have any changes to your overall health or wellbeing while taking Niclosamide, contact your healthcare provider right away.


Most physicians will recommend that you take your dose of Niclosamide on an empty stomach, one hour prior to a meal or a few hours after you've eaten. You may be advised that a light snack be taken with your dosage to prevent stomach upset.

Thoroughly chew the tablets and swallow them with a little water or crush them into a little water for dosing children. Typically one dose is sufficient to kill some types of tapeworm infestations; occasionally a second dose is required. Other forms of infestations will be prescribed a seven-day course of treatment, which may be repeated for a full fourteen days. Regardless of the treatment time you are prescribed, it is important to keep your dosing schedule and take your full prescribed amount of Niclosamide as written by your doctor.

Your prescription will be written especially for you and based on your overall health and the type of infestation you have as well as other factors. This is a general guideline for patient dosages; yours may be different. Always follow what your physician has prescribed for you.

Beef or fish tapeworm infestations

Adults will typically be prescribed two grams in a single dosage, repeated after one week if required. Children will have their dosage based on their body mass, in general being prescribed one gram single doses if they weight from eleven to thirty-four kilograms, one and a half grams as a single dose for children weighing over thirty-four kilograms, to be repeated after one week if required.

Dwarf tapeworm

Adult patients with this type of infestation will generally be prescribed a dose of two grams daily for a course of seven days, repeated after one week if required. Children will have their dosage based on their body mass; typically an initial dose of one gram the first day followed by 500 milligrams daily for six days after that if they weigh 11 to 34 kilograms. Children over 34 kilograms will typically receive one and a half grams the first dose followed by a single gram dose for the next six days. Again, this course may need to be repeated after one week.

Missing a dose of Niclosamide should not compel you to double dose under any circumstances. Take your missed dose as soon as you realize you missed it if it is far enough outside the time of your next dose. Do not double your doses.


Niclosamide is fast acting and well tolerated by most patients. If you have ever experienced a hypersensitive reaction to any medication, including Niclosamide, you should tell your physician about the circumstances prior to being prescribed this drug. Mention any reactions you've had to perfumes, dyes, preservatives or foods at this time as well.

Children over two years of age have been successfully treated with Niclosamide and have shown little side effects, similar to adult patients. Similarly, geriatric patients tolerate treatment with Niclosamide well and should not expect any difference in effectiveness or risk that would require an altered dosage due to age-related conditions.

Use of Niclosamide in women who are pregnant or women who are breastfeeding has proven to have minimal risks to infants and fetal development when used on these groups. Use of this medication while you a pregnant or nursing should be discussed with your physician.

Read all information provided to you in written form and ask any questions of your doctor or pharmacist on information that isn't clear to you.

Avoid taking other medications while you are on a course of treatment with Niclosamide or at least disclose your prescription requirements to your physician to ensure no dangerous interactions are possible. Include any non-prescription, herbal, vitamin or holistic supplements that you take as well.

Some foods, alcoholic beverages or tobacco products could interrupt the effectiveness of Niclosamide on your infestation or even cause unwanted effects on your health. Discuss the interaction of any foods, alcohol or tobacco products with your physician prior to taking this medication. Your physician will recommend to you whether you should take Niclosamide with food or how far to space your dosage before or after a meal.


Keep all follow-up appointments with your physician to make sure Niclosamide has worked to clear up the infestation completely, leaving no ill effects on your health for the long term. If you do not see an improvement in your symptoms in the few days after your first dosage, contact your healthcare provider right away. Your treatment may need to be repeated to completely eliminate the infestation from your body.

You may also be prescribed a laxative or enemas to be taken after your treatment of Niclosamide, which will help get rid of any larvae that remain in your system. Be sure to follow the directions prescribed for you on this medication as well with regard to timing and duration of the medication.

You may experience some mild disturbances in your gastrointestinal functions such as diarrhea, stomach cramps or vomiting accompanied by nausea. While this is possible, it doesn't happen in all patients and is typically short in duration, with relief experienced after the medication has been passed through the system.

If you suffer from com/health/chronic-constipation/">chronic constipation, your physician will need to know of this condition prior to treating you with Niclosamide. You may be prescribed a laxative or enema treatment prior to your dose of this medication.

Some medications work in conjunction with others to provide an overall health regimen for patients with multiple symptoms. Other medications should never be taken together for any reasons. While you are taking a prescription of Niclosamide, it is important to disclose any other medications you are taking and to include over the counter, herbal, holistic and even vitamin supplements as well to avoid any adverse reactions between the medications.


Retain the original packaging that your Niclosamide arrived in and use it to store this medication properly. Keep this medicine at room temperature, away from exposure to excessive light, heat or moisture. Do not allow Niclosamide to freeze and do not use it if it has become frozen. This medication, as well as others, should be kept out of sight and reach of children and pets.

Expired or unused Niclosamide dosages should be disposed of properly according to your physician's instructions for safety. If this is not provided to you by your physician, consult with your pharmacist on safe disposal practices.


Niclosamide is an anthelminthic style of medication, working to kill intestinal parasites known as tapeworms in children and adults as well as geriatric patients. Effective on most species of tapeworm, Niclosamide is under study as a cancer-fighting drug. This medication is immediately effective with one dose in many species of parasite but may also be given as a seven-day treatment. The tablets are chewable and crushable and should be taken with a small amount of water.

Niclosamide is well tolerated with few adverse effects on most patients. After the infestation is killed, it is passed through the stool and, in many cases, destroyed in the intestines. Some patients experience gastrointestinal effects that are temporary in nature and include nausea, diarrhea, vomiting and abdominal cramps. Other patients may experience rectal itching or skin rashes after taking Niclosamide. These symptoms are typically short live and usually disappear over time, but if they become a health concern, they should be reported to your physician.

Though this drug is safely used on most patients, women who are pregnant or breastfeeding should discuss the use of Niclosamide with their doctors. No scientific data has been provided on the use of this drug in children less than two years old, so the risks to infants and children should be considered prior to use of this medication.

Store Niclosamide at room temperature and do not expose it to excessive heat, cold or light. Dispose of any unused medication safely according to the manufacturer's directions, your physician's instructions or what your pharmacist recommends.