Is it possible to give Pyrantelum after 1.5 months from the previous treatment? Is it possible to give the drug in the form of tablets to a 7-year-old child?

For Pyrantelum, the right dose should be selected based on body weight. You did not provide information about how much the child weighs, so I can not determine whether and if so, how many tablets the child should take in order for the treatment to be effective and safe. Re-administration of the drug is not contraindicated, although I would recommend going to the doctor in advance and doing a fecal examination to confirm your diagnosis. I am attaching a helpful article: https://www.gdziepolek.pl/artykuly/wszy-owsiki-i-inne-przedszkolne-pasozyty