 Due to prolonged half life, associated with waterintoxication,the nasal spray has a black box warning from the FDA and is no longer recommended . For some authors oral formulations appear to be a safer alternative. However, based on clinical experience of less response rate with oral formulations, lower biodisponibility is suspected. Adult research confirms low bioavailability of tablets but also show major influences by food-intake and changes in gastro-intestinal motility. 