PRAZIQUANTEL

PRAZIQUANTEL
(pray-zi-kwon'tel)
Biltricide
Classifications: anthelmintic;
Therapeutic: anthelmintic
Prototype: Mebendazole
Pregnancy Category: B

Availability

600 mg tablets

Action

Synthetic agent with broad-spectrum anthelmintic activity against all developmental stages of schistosomes and other trematodes (flukes) and against cestodes (tapeworm). Increases permeability of parasite cell membrane to calcium. Leads to immobilization of their suckers and dislodgment from their residence in blood vessel walls.

Therapeutic Effect

Active against all developmental stages of schistosomes, including cercaria (free-swimming larvae). Activity against other trematodes (flukes) not fully understood; activity against cestodes (tapeworms) not clear but may be similar to that against schistosomes.

Uses

All stages of schistosomiasis (bilharziasis) caused by all Schistosoma species pathogenic to humans. Other trematode infections caused by Chinese liver fluke.

Unlabeled Uses

Lung, sheep liver, and intestinal flukes and tapeworm infections.

Contraindications

Hypersensitivity to drug; ocular cysticercosis. Safety in children <4 y is not established; women should not breast feed on day of praziquantel therapy or for 72 h after last dose of drug.

Cautious Use

Hepatic disease; cardiac arrhythmias; pregnancy (category B).

Route & Dosage

Schistosomiasis
Adult/Child (>4 y): PO 60 mg/kg in 3 equally divided doses at 4–6 h intervals on the same day, may repeat in 2–3 mo after exposure

Other Trematodes
Adult/Child (>4 y): PO 75 mg/kg in 3 equally divided doses at 4–6 h intervals on the same day

Cestodiasis (Adult or Intestinal Stage)
Adult: PO 10–20 mg/kg as single dose

Cestodiasis (Larval or Tissue Stage)
Adult: PO 50 mg/kg in 3 divided doses/d for 14 d

Administration

Oral

Give dose with food and fluids. Tablets can be broken into quarters but should NOT be chewed.
Advise patient to take sufficient fluid to wash down the medication. Tablets are soluble in water; gagging or vomiting because of bitter taste may result if tablets are retained in the mouth.
Treatment for cestodiasis (tapeworm) is followed by gentle purgation 2 h after drug administration to facilitate rapid removal of tapeworms and ova.
Store tablets in tight containers at <30° C (86° F).

Adverse Effects (≥1%)

CNS: Dizziness, headache, malaise, drowsiness, lassitude, CSF reaction syndrome (exacerbation of neurological signs and symptoms such as seizures, increased CSF protein concentration, increased anticysticercal IgG levels, hyperthermia, intracranial hypertension) in patient treated for cerebral cysticercosis. GI: Abdominal pain or discomfort with or without nausea; vomiting, anorexia, diarrhea. Hepatic: Increased AST, ALT (slight). Skin: Pruritus, urticaria. Body as a Whole: Fever, sweating, symptoms of host-mediated immunologic response to antigen release from worms (fever, eosinophilia).

Diagnostic Test Interference

Be mindful that selected drugs may interfere with stool studies for ova and parasites: iron, bismuth, oil (mineral or castor), Metamucil (if ingested within 1 wk of test), barium, antibiotics, antiamebic and antimalarial drugs, and gallbladder dye (if administered within 3 wk of test).

Interactions

Drug: Phenytoin can lead to therapeutic failure. Food: Grapefruit juice (>1 qt/d) may increase plasma concentrations and adverse effects.

Pharmacokinetics

Absorption: Rapidly, 80% reaches systemic circulation. Peak: 1–3 h. Distribution: Enters cerebrospinal fluid. Metabolism: Extensively to inactive metabolites. Elimination: Primarily in urine. Half-Life: 0.8–1.5 h.

Nursing Implications

Assessment & Drug Effects

Patient is reexamined in 2 or 3 mo to ensure complete eradication of the infections.

Patient & Family Education

Do not drive or operate other hazardous machinery on day of treatment or the following day because of potential drug-induced dizziness and drowsiness.
Usually, all schistosomal worms are dead 7 d following treatment.
Contact physician if you develop a sustained headache or high fever.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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