Praziquantel (PZQ) - side effect and pregnancy

Praziquantel (PZQ) is a medication used to treat a number of types of parasitic worm infections in mammals, birds, amphibians, reptiles, and fish. In humans specifically, it is used to treat schistosomiasis, clonorchiasis, opisthorchiasis, tapeworm infections, cysticercosis, hydatid disease, and other fluke infections. It should not be used for worm infections of the eye.

The majority of side effects develop due to the release of the contents of the parasites as they are killed and the consequent host immune reaction. The heavier the parasite burden, the heavier and more frequent the side effects normally are :- 

Central nervous system (CNS)

Frequently occurring side effects are - 

• Dizziness
• Headache
• Malaise
• Drowsiness, somnolence, fatigue, and vertigo have also been seen. 
• Almost all patients with cerebral cysticercosis experience CNS side effects related to the cell-death of the parasites (headache, worsening of pre-existing neurological problems, seizures, arachnoiditis, and meningism). These side effects may be life-threatening and can be reduced by co-administration of corticosteroids. All patients with cerebral cysticercosis are strongly recommended to be hospitalized during treatment.

Gastrointestinal tract: -  About 90% of all patients have abdominal pain or cramps with or without nausea and vomiting. Diarrhea may develop and may be severe with colic. Sweating, fever, and sometimes bloody stools may occur together with diarrhea.

Liver: - Asymptomatic and transient increases of liver enzymes (AST and ALT) are noted frequently (up to 27%). No case of symptomatic liver damage has been seen so far.

Sensitivity reactions: - Urticaria, rash, pruritus and eosinophilia in white blood cell counts

Other locations/body as a whole: - Lower back pain, myalgia, arthralgia, fever, sweating, various cardiac arrhythmias, and hypotension.

 

Pregnancy

The WHO states praziquantel is safe during pregnancy. Animal studies have failed to reveal evidence of fetal harm. Praziquantel is effective in reducing schistosomiasis during pregnancy. Another trial found that treatment with praziquantel did not increase the rates of low birthweight, fetal death, or congenital anomalies.

Can pregnant women be treated with praziquantel?

Praziquantel is extremely safe and WHO recommends that pregnant women infected with the disease should be treated. But as a general precaution, WHO recommends treatment should be taken after the first trimester.