Levamisole

An anthelmintic and immunomodulatory drug

Levamisole is a medication primarily used as an anthelmintic to treat parasitic worm infections. It also has immunomodulatory properties and has been used in the past as an adjunct in the treatment of certain cancers. However, its use has declined due to the availability of newer drugs and concerns about side effects.

Medical uses

Levamisole was originally developed as an anthelmintic for the treatment of helminthiasis, particularly infections caused by roundworms such as Ascaris lumbricoides and hookworms. It works by paralyzing the muscles of the worms, which are then expelled from the body.

In addition to its anthelmintic properties, levamisole has been used as an immunomodulator. It was once used in combination with fluorouracil in the adjuvant treatment of colon cancer, as it was thought to enhance the immune response against cancer cells. However, its use in this context has largely been replaced by more effective and safer treatments.

Mechanism of action

Levamisole acts as an agonist at the nicotinic acetylcholine receptors of the nematode neuromuscular junction, causing spastic paralysis of the worm. This action is similar to that of the natural neurotransmitter acetylcholine, but levamisole is more resistant to degradation by acetylcholinesterase.

As an immunomodulator, levamisole is thought to restore depressed immune function by stimulating the proliferation and activity of T-lymphocytes and macrophages. However, the exact mechanism by which it modulates the immune system is not fully understood.

Side effects

The use of levamisole can lead to several side effects. Common adverse effects include nausea, vomiting, diarrhea, and abdominal pain. More serious side effects include agranulocytosis, a potentially life-threatening condition characterized by a severe reduction in the number of white blood cells, which can lead to increased susceptibility to infections.

Levamisole has also been associated with vasculitis, a condition that involves inflammation of the blood vessels, and leukoencephalopathy, a rare disorder affecting the white matter of the brain.

Controversial uses

Levamisole has gained notoriety for its use as an adulterant in cocaine. It is often added to cocaine to increase the bulk and enhance the stimulant effects. However, this practice is dangerous, as levamisole can cause severe side effects, including agranulocytosis and vasculitis, in users.

Regulatory status

Due to its side effects and the availability of safer alternatives, the use of levamisole in humans has been restricted or discontinued in many countries. It is still used in veterinary medicine for the treatment of parasitic infections in animals.

Related pages

• Anthelmintic
• Immunomodulator
• Colon cancer
• Cocaine