The invention relates to the guanine derivatives of general formula (I), and to hydrates or solvents thereof, for use as neuropeptide FF receptor antagonists in the treatment of pains and hyperalgesia, of withdrawal symptoms of addiction to alcohol, psychotropic drugs or nicotine and in the prevention of or recovery from these addictions, for the regulation of insulin release, food intake, memory functions, blood pressure, electrolyte and energy metabolism, and in the treatment of urinary incontinence.