Praziquantel
[CAS# 55268-74-1]

Identification

• Classification: API >> Antiparasitic drug >> Anti-fungal medicine
• Name: Praziquantel
• Synonyms: 2-Cyclohexyl-carbonyl-1,3,4,6,7,11b-hexahydro-2H-pyrazine(2,1-a)isoquinoline-4-one
• Molecular Formula: C₁₉H₂₄N₂O₂
• Molecular Weight: 312.41
• CAS Registry Number: 55268-74-1
• EC Number: 259-559-6
• SMILES: C1CCC(CC1)C(=O)N2CC3C4=CC=CC=C4CCN3C(=O)C2

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H412
• Safety Statements: P264-P270-P273-P301+P312+P330-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H332
Carcinogenicity	Carc.	2	H351
Acute toxicity	Acute Tox.	4	H312

Discovery and Applications

Praziquantel is an anthelmintic agent widely used in the treatment of various parasitic infections caused by flatworms, particularly schistosomiasis and other cestode infections. The compound was first synthesized in the early 1970s by researchers at the German pharmaceutical company Bayer AG. The discovery of praziquantel was a significant milestone in the field of parasitology, as it provided an effective treatment option for diseases that had been challenging to manage with existing therapies.

The initial development of praziquantel was part of a broader effort to address the global burden of parasitic infections, particularly in tropical and subtropical regions where these diseases are endemic. Schistosomiasis, for example, is a major public health issue affecting millions of people worldwide, often leading to severe morbidity and long-term complications. Praziquantel emerged from a systematic screening of compounds aimed at identifying effective agents against schistosomiasis. Its mechanism of action involves increasing the permeability of the parasite's cell membranes to calcium ions, resulting in paralysis and death of the worm.

Following its discovery, praziquantel underwent extensive clinical trials that demonstrated its efficacy and safety in humans. It quickly became the drug of choice for treating schistosomiasis and was introduced into clinical practice in the late 1970s. Since then, it has been included in the World Health Organization's list of essential medicines, highlighting its importance in public health.

In addition to schistosomiasis, praziquantel is effective against a range of other helminthic infections, including infections caused by cestodes such as Taenia saginata and Echinococcus granulosus. Its broad-spectrum activity and favorable pharmacokinetic profile have made it a key player in both human and veterinary medicine.

The application of praziquantel extends beyond treatment. It has been used in mass drug administration campaigns aimed at controlling and eliminating schistosomiasis in endemic regions. These public health initiatives have proven successful in reducing the prevalence of the disease and its associated complications. The drug is typically administered orally and is well-absorbed, with a rapid onset of action, making it suitable for single-dose treatments.

Research into praziquantel continues, focusing on improving formulations, exploring its use in combination therapies, and addressing challenges related to drug resistance. Ongoing studies are also investigating its efficacy in treating other parasitic infections and its potential use in different populations, including pediatric and immunocompromised patients.

Overall, the discovery and application of praziquantel represent a significant advancement in the fight against parasitic diseases. Its effectiveness, safety, and impact on public health underscore its importance in global health initiatives aimed at controlling and eliminating neglected tropical diseases.

References

1984. Treatment of Schistosoma mekongi with praziquantel in Cambodian refugees in holding centres in Prachinburi province, Thailand. Transactions of the Royal Society of Tropical Medicine and Hygiene, 78(1).
DOI: 10.1016/0035-9203(84)90066-x

1994. Characterisation of praziquantel metabolism by rat liver microsomes using cytochrome P450 inhibitors. Biochemical Pharmacology, 48(9).
DOI: 10.1016/0006-2952(94)90464-2

2024. Hymenolepiasis. Handbook of Management of Zoonoses.
DOI: 10.1007/978-981-99-9885-2_100