Levamisole: Anthelminthic agent

Levamisole: Anthelminthic agent

Group: anthelminthic agent
Tablet 40 mg, 50 mg (as hydrochloride)
Syrup 40 mg/5 ml

General information

Levamisole, the (-)-isomer of tetramisole, acts by paralysing the musculature of susceptible nematodes. Unable to maintain their anchorage, the worms are ejected by normal peristaltic action, usually within 24 hours.

Levamisole: Anthelminthic agent

Levamisole is rapidly and almost completely absorbed from the gastrointestinal tract. Peak plasma concentrations occur within 2 hours and the plasma half-life is about 4 hours. It is extensively metabolized in the liver and is excreted in the urine as metabolites and unchanged drug.

Levamisole is used with another cancer medicine (fluorouracil) to help make it work better against cancer of the colon.

Levamisole is available only with your doctor’s prescription.


The dose of levamisole will be different for different patients. Follow your doctor’s orders or the directions on the label. The following in formation includes only the average doses of levamisole. 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.

Missed Dose

If you miss a dose of levamisole, skip the missed dose and go back to your regular dosing schedule. Do not double doses.



Clinical applications

Levamisole, the levorotatory and biologically active isomer of the racemic tetramisole, was discovered by Janssen Pharmaceutica in 1966 and developed as a broad-spectrum anthelmintic for use in a variety of mammalian and avian species. While widely used as an antiparasitic agent in ruminants, with a number of immunomodulatory uses still under development in humans and other species, levamisole has not found wide application as an anthelmintic in dogs and cats, principally because of the narrow therapeutic index.


Levamisole is a synthetic imidazothiazole derivative that has been widely used in treatment of worm infestations in both humans and animals. As an anthelmintic, it probably works by targeting the nematode nicotinergic acetylcholine receptor. As an immunomodulator, it appears that Levamisole is an immunostimulant which has been shown to increase NK cells and activated T-cells in patients receiving this adjuvantly along with 5FU for Stage III colon cancer.

Mechanism of action

The mechanism of action of levamisole as an antiparasitic agent appears to be tied to its agnositic activity towards the L-subtype nicotinic acetylcholine receptors in nematode muscles. This agonistic action reduces the capacity of the males to control their reproductive muscles and limits their ability to copulate. The mechanism of action of Levamisole as an anticancer drug in combination with fluorouracil is unknown. The effects of levamisole on the immune system are complex. The drug appears to restore depressed immune function rather than to stimulate response to above-normal levels. Levamisole can stimulate formation of antibodies to various antigens, enhance T-cell responses by stimulating T-cell activation and proliferation, potentiate monocyte and macrophage functions including phagocytosis and chemotaxis, and increase neutrophil mobility, adherence, and chemotaxis.

Levamisole Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

  • Fever or chills
  • unusual feeling of discomfort or weakness


  • Black, tarry stools
  • blood in urine or stools
  • cough or hoarseness
  • lower back or side pain
  • painful or difficult urination
  • pinpoint red spots on skin
  • unusual bleeding or bruising

Check with your doctor as soon as possible if any of the following side effects occur:

Less common

  • Sores in mouth and on lips


  • Blurred vision
  • confusion
  • convulsions (seizures)
  • lip smacking or puffing
  • numbness, tingling, or pain in face, hands, or feet
  • paranoia (feelings of persecution)
  • puffing of cheeks
  • rapid or worm-like movements of tongue
  • trembling or shaking
  • trouble in walking
  • uncontrolled movements of arms and legs

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Diarrhea
  • metallic taste
  • nausea

Less common

  • Anxiety or nervousness
  • dizziness
  • headache
  • mental depression
  • nightmares
  • pain in joints or muscles
  • skin rash or itching
  • trouble in sleeping
  • unusual tiredness or sleepiness
  • vomiting

Levamisole may cause a temporary loss of hair in some people. After treatment has ended, normal hair growth should return.

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

Albendazole: The bioavailability of Albendazole can be increased when combined with Levamisole

Ivermectin: The bioavailability of Ivermectin can be increased when combined with Levamisole.

Food Interactions

·  Take on an empty stomach.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.



·         https://www.drugbank.ca/drugs/DB00848

·         https://www.drugs.com/cons/levamisole.html

·        http://apps.who.int/medicinedocs/en/d/Jh2922e/3.2.2.html

·        https://www.sciencedirect.com/topics/neuroscience/levamisole

  •      Stephen W Page, in Small Animal Clinical Pharmacology (Second Edition), 2008
  •      Anahid Jewett, Han-Ching Tseng, in Pharmacology and Therapeutics for Dentistry (Seventh Edition), 2017

·  P.J.J. van Genderen, in Side Effects of Drugs Annual, 2009

· P.J.J. van Genderen, in Side Effects of Drugs Annual, 2008



Leave a Reply

%d bloggers like this: