Drug information of Praziquantel

Mechanism of effect

Increases cell membrane permeability to calcium in schistosomes causing the worm to dislodge following the paralysis of worm musculature

Pharmacodynamic

Praziquantel effects the permeability of the cell membrane resulting in the contraction of schistosomes. The drug further causes vacuolization and disintegration of the schistosome tegument. The effect is more marked on adult worms compared to young worms.

 An increased calcium influx may play an important role. Secondary effects are inhibition of glucose uptake, lowering of glycogen levels and stimulation of lactate release. The action of praziquantel is limited very specifically to trematodes and cestodes; nematodes (including filariae) are not affected.

Pharmacokinetics

Absorption: ~80% (oral)

Distribution: CSF concentration is 14-20% of plasma concentration

Protein Bound: ~80%

Metabolism: Extensive first-pass effect

Half-life 0.8-1.5 hr (parent drug); 4.5 hr (metabolites)

Peak Plasma Time: 1-3 hr

Excretion: Urine (99% as metabolites)

Dosage

Adults:

Schistosomiasis

20 mg/kg PO TID for 1 day (at intervals 4-6 hr) 

Clonorchiasis, Opisthorchiasis

75 mg/kg/d divided PO TID for 1 day (at intervals 4-6 hr) 

Pediatrics:

Schistosomiasis

<4 years: Safety and efficacy not established

≥4 years: 20 mg/kg PO TID for 1 day (at intervals 4-6 hr) 

Clonorchiasis, Opisthorchiasis

< 4 years: Safety and efficacy not established

≥4 years: 75 mg/kg/d divided PO TID for 1 day (at intervals 4-6 hr) 

Drug contraindications

hypersensitivity to this drug

Side effects

Diarrhea , Headache , nausea , vomiting , vertigo , urticaria , fever , itching , difficulty urinating , Abdominal pain , Rash , Appetite suppression

Interactions

Rifabutin , Rifapentine , Albendazol , Oxecarbazepin , Bosentan , Primidone , Tenofovir , Rifampin , Pentobarbital , Chloroquine , Fosphenytoin , nafcillin , Cimetidine , Phenobarbital , Phenytoin , Hydroxychloroquine , Carbamazepine , Enzalutamide , Efavirenz , Etravirine , Dabrafenib

Alerts

Coadministration with moderate CYP3A4 inducers (eg, phenytoin, phenobarbital, carbamazepine, dexamethasone) may reduce blood levels

Use with caution in patients with cardiac abnormalities.

It is recommended to hospitalize patients with cerebral cysticercosis for the duration of treatment.

Use with caution in patients with moderate-to-severe hepatic impairment

Use not recommended in patients with a history of seizures or signs of central nervous system involvement .

Points of recommendation

Swallow quickly with water, otherwise risk of regurgitation due to bitter taste

Pregnancy level

B

Related drugs

Albendazol , Ivermectin , Levamisole , Mebendazol , Niclosamide , Pyrantel