Tetramisole hydrochloride
[CAS# 5086-74-8]

Identification

• Classification: API >> Antiparasitic drug >> Anthelmintic
• Name: Tetramisole hydrochloride
• Synonyms: Levamisole hydrochloride; DL-2,3,5,6-Tetrahydro-6-phenylimidazo[2,1-b]thiazole hydrochloride
• Molecular Formula: C₁₁H₁₂N₂S.HCl
• Molecular Weight: 240.75
• CAS Registry Number: 5086-74-8
• EC Number: 225-799-5
• SMILES: C1CSC2=NC(CN21)C3=CC=CC=C3.Cl

Properties

• Solubility: <9 mg/mL (DMSO) (Expl.)
• Melting Point: 266-267 °C (Expl.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P270-P271-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

Tetramisole hydrochloride is an anthelmintic drug used primarily for the treatment of parasitic worm infections. It is particularly effective against a range of nematode (roundworm) infections, including those caused by *Ascaris lumbricoides* (giant roundworm), *Trichuris trichiura* (whipworm), and *Necator americanus* (hookworm). Tetramisole hydrochloride is used both in humans and animals for the treatment of these infections.

The drug works by paralyzing the worms, which then lose their ability to maintain their position in the intestine, allowing them to be expelled from the body. Tetramisole acts as a depolarizing neuromuscular blocker, primarily affecting the worms' muscles by interfering with their ability to contract. This leads to paralysis and the eventual expulsion of the parasites.

In humans, tetramisole hydrochloride is typically administered orally in tablet form. The dose and duration of treatment can vary depending on the type and severity of the infection. It is usually well-tolerated, though some patients may experience mild side effects such as nausea, dizziness, or gastrointestinal upset. In rare cases, allergic reactions or more severe adverse effects may occur.

Tetramisole hydrochloride is sometimes used as a veterinary medication to treat parasitic infections in livestock, including cattle and sheep. Its use in animals has been associated with effective control of gastrointestinal parasites, helping to improve animal health and productivity.

Tetramisole hydrochloride is also known for its immunomodulatory effects, which have been studied in clinical settings. It has been shown to have some impact on the immune system, specifically in stimulating T-lymphocytes, which play a role in immune responses. However, this immunomodulatory property has not been the primary focus of its clinical use, and tetramisole is not typically used as an immune system enhancer in clinical practice.

Despite its broad use as an anthelmintic, tetramisole hydrochloride is no longer commonly prescribed for human parasitic infections in many countries. The development of newer, more effective anthelmintic drugs has led to a decline in the use of tetramisole hydrochloride. However, it is still sometimes used in specific clinical situations, particularly in veterinary medicine.

In summary, tetramisole hydrochloride is an anthelmintic drug used primarily to treat roundworm infections. It works by paralyzing the worms and aiding in their expulsion from the body. While it is generally well-tolerated, its use in humans has declined with the introduction of more effective alternatives. Tetramisole is also used in animals to control gastrointestinal parasites and has been studied for its immunomodulatory effects.

References

2023. Levamisole Derivatives As Immune Modulators for the Treatment of Amyotrophic Lateral Sclerosis (ALS). Future Medicinal Chemistry, 15(8).
DOI: 10.4155/fmc-2023-0028

1973. Letter: Tetramisole in the treatment of Ancylostoma duodenale and ascaris Lumbricoides infections in Egyptian farmers. Transactions of the Royal Society of Tropical Medicine and Hygiene, 67(4).
DOI: 10.1016/0035-9203(73)90132-6

1973. Epidemiological studies on gastro-intestinal nematode parasites of sheep. The control of infection in lambs on contaminated pasture. Research in Veterinary Science, 15(2).
DOI: 10.1016/s0034-5288(18)33835-9