Secretin Therapy for Autism

This what we know about Secretin as of January 1999:

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 currently comes from the intestine of pigs, although a synthetic human form may soon be available. The safety and efficacy of pig Secretin has been approved by the U.S. Food and Drug Association (FDA) for single-dose use in diagnosing gastrointestinal problems. The use of Secretin for any other purpose is considered an "off-label" use for which the FDA has not issued formal approval.

Although Secretin is generally considered safe for single dose diagnostic use, no data is yet available as to the safety of repeated doses over time and no data have been submitted on its safety and efficacy for children. No optimum dosage or recommended frequency of infusion for the treatment of autism have been determined at this time. There is no agreed upon procedure to determine which children may potentially benefit from this drug. Because Secretin is derived from pigs, there is a potential for development of antibodies (allergies) to Secretin.

Who is the best candidate for Secretin?

We don't know. So far, none of the expected predictors of effect has proven valid, although there is a slight tendency for children with diarrhea to respond better than children without, but the difference is negligible. Original reports suggested that 50% of children who are given secretin show some benefit. More recent data suggests that 75% of patients show benefit, although we cannot identify a sub-group that does notably better or worse than the group as a whole.

What is the best dosage?

We don't know. The manufacturer suggests 1.0-2.0 Clinical Units (CU) of Secretin per kg of body weight (for diagnosing digestive disorders). Data suggests that ranges of 0.5 to 7.3 CU/kg are being given. If we consider only those between 2.0 CU/kg and 5.2 CU/kg, disregarding the few cases on either extreme, there is no perceptible advantage to giving higher doses, although higher doses have more likelihood of adverse side-effects. We can guess, that from present data, the optimal dose may be somewhere between 2.0 CU/kg and 3.5 CU/kg.

What are the adverse effects?

About 33% of children showed some adverse effects, mostly hyperactivity and some aggressiveness for a few days after the IV infusion. In only a few cases were the problems severe.

What are the benefits?

Many....eye contact, awareness, sociability, speech, better sleep.

What is the optimal schedule of administration?

Again, we don't know. Some say 5-6 weeks. The benefits, when they occur, can start quite quickly, and seem to peak in children that respond, at about the end of the second week. The optimal delay between infusion and evaluative testing is about 2-3 weeks.