4 -- 1 - piperazinyl ]- 3 - trifluoromethylbenzoylguanidine hydrochloride and its hydrates , processes for preparing this benzoylguanidine salt and its hydrates , pharmaceutical compositions containing this benzoylguanidine salt and its hydrates , and its use in treating diseases , particularly those in which inhibition of the cellular na + / h + exchange is of therapeutic benefit .