1. Compliance policy for certain compounding of oral oxitriptan (5-HTP) drug products for patients with tetrahydrobiopterin (BH4) deficiency: immediately in effect guidance for industry Publication: Silver Spring, MD : Center for Drug Evaluation and Research, July 2019 Subject(s): Drug Compounding -- standards5-Hydroxytryptophan -- therapeutic usePhenylketonurias -- drug therapyGuideline AdherenceHumansUnited StatesUnited States. Department of Health and Human Services.United States. Food and Drug Administration.United States.