Efficacy of Praziquantel in the Treatment of Platynosomum fastosum in Cats with Natural Infections

Abstract

Treatments for Platynosomum fastosum—the liver fluke of cats—have been developed based on fecal egg counts. Post mortem fluke counts are required to understand true efficacy. In this study, two praziquantel treatment regimens were evaluated using post mortem fluke counts: a high-dose treatment (HT) of 20 mg/kg body weight (BW) administered intramuscularly (IM) once a day for three consecutive days and a low-dose treatment (LT) of 5 mg/kg BW administered once (IM) and repeated 14 days later. A continual enrolment study design was used with 16 naturally infected cats randomly allocated in blocks of four to the HT (eight cats) or LT (eight cats) group. Treatment success, defined as absence of live flukes post mortem, was determined 10 days after the last treatment. Pre- and post-treatment fecal egg counts (centrifugation with Sheather’s sugar flotation solution) and bile egg counts (obtained via percutaneous ultrasound guided cholecystocentesis) were evaluated as supportive efficacy data. Twelve cats completed the study with two cats withdrawn from each group. Neither treatment was 100% effective. In the HT group, three of six cats had live flukes, albeit low numbers, at post mortem, while all six LT group cats had live flukes. While fecal and bile egg counts were reduced in both group, they were not reflective of the true infection status of the cats post mortem.

Treatment of primate platynosomosis: A word of caution about the use of praziquantel in marmosets

“…There is a lack of studies that aim to establish parasitic intensity as a function of the number of eggs of P. illiciens in both cats and marmosets. However, cats with platynosomosis treated with PZQ showed a substantial reduction in worm burden and FEC values 13 . Previously, other studies with biliary flukes also revealed a direct correlation between worm burden and FEC 29‐31 .…”

“…In feline platynosomosis, different treatment schedules and dosages of PZQ have been adopted. For example, doses of 20 mg/kg BW once a day for three to five consecutive days were used by different authors 12‐14,16,28 . In most studies, monitoring of efficacy through qualitative analysis of parasite eggs in feces was performed, but quantitative evaluation was not considered.…”

“…However, attempts at treatment in naturally infected animals have generally been more common and justified by the difficulty of maintaining the cycle of Platynosomum spp. in the laboratory 11,13 …”

“…In fact, the drugs already used in the treatment of platynosomosis in non‐human primates were empirically adopted 6,10 . There are reports of drug efficacy, particularly of praziquantel (PZQ), in cats infected with this fluke 11‐13 . However, the efficacy and potential complications of some treatment schedules are not completely known, since the drugs that have been used, including PZQ, their dosage and efficacy are varied 11‐16 …”

Chromatographic Quantification of Ivermectin and Pranziquantel in the Tablets Using Stability Indicating RP-HPLC Method

“…In dogs, horses and cats, praziquantel is prescribed to treat tapeworm infections, pancreas fluke and blood flukes. [9][10][11] Praziquantel is chemically known as (RS)-2-(Cyclohexylcarbonyl)-1,2,3,6,7,11b-hexahydro-4H-pyrazino[2,1-a]isoquinolin-4-one ( Figure 2). Ivermectin and praziquantel combination is available in paste form (Equimax paste with strength 14.03% praziquantel and 1.87% ivermectin) and tablet dosage form (Ipraz tablet with strength 2 mg ivermectin and 50 mg praziquantel).…”