Even though pyrantel pamoate is available over the counter, clinicians should screen for liver disease, anemia, and special populations before recommending therapy.
Absolute contraindications are limited to hypersensitivity to pyrantel salts or formulation excipients. Relative contraindications involve situations where cholinergic effects or worm burden could destabilize the child, including severe hepatic impairment, malnutrition with iron deficiency, infants under 2 years, and pregnancy without obstetric oversight.
Documented hypersensitivity to pyrantel salts or formulation excipients — prior immediate reactions such as angioedema, bronchospasm, or urticaria warrant selecting an alternative anthelmintic.
Concurrent piperazine therapy, because opposing neuromuscular mechanisms reduce efficacy and can precipitate aberrant worm migration according to product labeling.
Severe hepatic impairment or cholestatic disease; hepatic metabolism is the primary clearance pathway and accumulation has been associated with transient aminotransferase elevations — monitor liver tests or consider a specialist-directed alternative.
Infants younger than 2 years unless a pediatric infectious diseases physician supervises treatment; safety data are limited and chewable formulations pose choking risk.
Pregnancy, particularly during the first trimester; reserve therapy for confirmed enterobiasis when non-pharmacologic measures fail and coordinate obstetric follow-up.
Marked malnutrition or anemia where repeat dosing may be required; ensure nutritional support and anemia correction before retreatment.