Because its safety and efficacy have not been adequately tested for this purpose, the National Institutes of Health does not currently have a formal position on the therapeutic use of secretin in the treatment of autism. However, to respond to the many inquiries received as a result of media attention on this topic, the National Institute of Child Health and Human Development (NICHD) provides the following information. This information does not constitute a recommendation or endorsement for the use of secretin to treat autism.
Secretin is a polypeptide neurotransmitter (chemical messenger), one of the hormones that controls digestion. According to the manufacturer (Ferring Laboratories, Suffern, NY) the primary action of secretin is to "increase the volume and bicarbonate content of secreted pancreatic juices." Secretin is currently prepared from the duodenum of pigs, although a synthetic human version may soon be available. The safety and efficacy of porcine (pig) secretin has been approved by the US Food and Drug Administration (FDA) for single dose use in diagnosing gastrointestinal problems such as impaired pancreatic function or gastric problems such as ulcers in adults (specifically for diagnosis of pancreatic exocrine disease, as an adjunct in obtaining desquamated pancreatic cells for cytopathologic examination, and for diagnosis of gastrinoma--Zollinger-Ellison syndrome). For those uses, a small amount (1 CU/kg of body weight) is administered by intravenous infusion and the consequent stimulation of pancreatic secretions is evaluated. The use of secretin for any other purpose is considered an "off-label" use, i.e., a use for which the FDA has not issued formal approval.
Although secretin is generally considered safe for single dose diagnostic use, no data are available yet as to the safety of repeated doses over time and no data have been submitted on its safety and efficacy for children. No double-blind, placebo-controlled studies of secretin treatment in autism have been conducted. No optimum dosage or recommended frequency of infusion in the treatment of autism have been determined at this time. At the present time, there is no agreed upon procedure to determine which children may potentially benefit from the use of this drug. Physicians are advised that, like all drugs, there is the possibility of adverse events that may be associated with individual allergies or susceptibilities. An initial small test dose is recommended as a precaution against allergic reactions and appropriate measures for the treatment of acute hypersensitivity reactions should be available.
Research on Secretin
Although more than 100 children have received secretin injections for the treatment of autism, only one study on its use in three children has been published at this time. The authors of that study discuss possible mechanisms of action in the context of "gut-brain" theories of autism that propose a link between the gastrointestinal disorders observed in many children with autism and their brain dysfunctions. The citation for that study and the study abstract are given below:
Horvath K,* Stefanatos G, Sokolski KN, Wachtel R, Nabors L, and Tildon JT. "Improved social and language skills after secretin administration in patients with autistic spectrum disorders." Journal of the Association for Academic Minority Physicians 1998; 9:9-15.
"We report three children with autistic spectrum disorders who underwent upper gastrointestinal endoscopy and intravenous administration of secretin to stimulate pancreaticobiliary secretion. All three had an increased pancreaticobiliary secretory response when compared with nonautistic patients (7.5 to 10 mL/min versus 1 to 2 mL/min). Within 5 weeks of the secretin infusion, a significant amelioration of the children's gastroinstestinal symptoms was observed, as was a dramatic improvement in their behavior, manifested by improved eye contact, alertness, and expansion of expressive language. These clinical observations suggest an association between gastrointestinal and brain function in patients with autistic behavior."
*Department of Pediatrics, University of Maryland at Baltimore, 22 South Greene Street, Box 140/N5W70, Baltimore, Maryland 21201-1595 (Fax: 410 328-1072).
Supplies of secretin are not available from the National Institutes of Health. Information about ordering secretin can be obtained from the Autism Research Institute (fax: 619 563-6840) or from the manufacturer, Ferring Laboratories, Suffern, NY (914 333-8900). A booklet containing information about secretin, including summaries of non-autism studies of secretin and answers to frequently asked questions, can be obtained for $15 from the Autism Research Institute (ARI), 4182 Adams Avenue, San Diego, CA 92116 (websites: autism.com/ari/ and secretin.com) or via fax to ARI with credit card information (fax: 619 563-6840).
Whether secretin will prove to be an effective treatment for autism and/or for gastrointestinal disorders associated with autism cannot be determined at this time. The NICHD invites qualified applicants to submit applications for research funding to explore its safety, efficacy, and mechanism of action.