Praziquantel is an anthelmintic used principally against tapeworms in companion animals and horses. It is also used for selected trematode infections and less common cestodes in other veterinary species. Single-ingredient and combination products provide different overall parasite coverage, while praziquantel supplies the principal cestocidal component.
Praziquantel alters calcium permeability and calcium-dependent signaling in susceptible parasites, producing rapid contraction and paralysis. Disruption of the tegument exposes parasite tissues to host digestive and immune processes and contributes to elimination. The relative importance of specific channel targets varies among parasite groups. This activity accounts for its effects against susceptible cestodes and selected trematodes.
Major parenteral exposure can cause marked ataxia and depression, especially in cats. Vomiting is common at high oral exposure; animal and formulation sensitivity differ.
Select the species, body-weight qualification and route carefully. Inconsistent injection weight boundaries in the reported guidance are not interpolated.
Product-specific Droncit tables contain rounded pound boundaries rather than continuous weight ranges. Dog injection 56.8 mg/mL: under 5 lb 17 mg; 6-10 lb 28.4 mg; 11-25 lb 56.8 mg; over 25 lb 0.2 mL/5 lb with 3-mL maximum. Oral 34-mg tablets: under 5 lb 17 mg; 6-10 lb 34 mg; 11-15 lb 51 mg; 16-30 lb 68 mg; 31-45 lb 102 mg; 46-60 lb 136 mg; over 60 lb 170 mg maximum. Gaps are not interpolated.
Feline product table: oral 23-mg tablets, under 4 lb 11.5 mg, 5-11 lb 23 mg, above 11 lb 34.5 mg. Injectable table has an ambiguous final 10-lb boundary. Drontal/Drontal Plus Giardia regimens concern the entire combination, not praziquantel alone. Injectable formulation is toxic to finches; medicated-cake delivery lacks predictable individual intake.
