This protocol needs to be updated. I used to cure intestinal flukes and some other trematodes. But praziquantel is useless in case of liver flukes.
"Although success has been seen in the treatment of F hepatica with dosages of 75 mg/kg tid for one day (23), there are many reports of post therapy relapse in both acute and chronic fascioliasis, even when dosages as high as 75 mg/kg/day are used for seven days (7,24–26). Such a treatment failure was observed in the present patient. Failure may relate to the resistive properties of the F hepatica tegument."
Some authors recommend Triclabendazole but I read that Fasciola hepatica can resist this drug as well. And finally Nitazoxanide was recommended as a drug of choice:
"Nitazoxanide efficacy against fascioliasis is worth mentioning, becoming an alternative to triclabendazole.
Moreover, its usefulness for the treatment of human cases not responding to triclabendazole  is of important additional value, given the spread of the resistance to this drug. However, it should be noted that a triclabendazole-resistant F. hepatica infected patient not responding to nitazoxanide treatment has recently been reported in the Netherlands . In animals, triclabendazole resistance was first described in Australia , later in Ireland , , Scotland , the Netherlands , , and Spain . Very recently it has also been found in southern Brazil  and Argentina . Up to that moment, triclabendazole resistance only concerned livestock in animal endemic areas, but unfortunately it has very recently been also described in humans  in a human highly endemic area such as Cajamarca, Peru ."