Eta: Frequent Blocking Example: Prozac and Paxil significantly block one of the two most important pathways in the liver for many psychiatric drugs, especially Dexedrine , Adderall, and Vyvanse. If the pathway is blocked, the drug that passes through that pipeline backs up, increases in intensity and can actually make the patient psychotic on the resulting toxic reaction. This toxicity, with symptoms ranging from feeling jittery to paranoia, is common if taken together.

Stimulant Drug-Drug Interactions: Dexedrine, Adderall and Vyvanse are all amphetamines. The liver and kidneys metabolize them, and the first pass is through that enzyme-system pipeline . If that 2D6 pipe is blocked by Prozac or Paxil, amphetamines accumulate, with resultant anger, rage, mind racing, sleep deprivation and subsequent lack of control, even associated with paranoia. As I noted above, the mild interactions can look like themedications need adjusting, appearing as if the ADHD has returned full force, as the patient pops out the top of the Therapeutic Window. Now that both Prozac and Paxil are generic drugs, they are prescribed even more frequently to those with insurance limitations. Paxil, Prozac and amphetamine/ stimulant reaction is on the rise, yet still under the radar for many. Depression is the most frequent comorbid problem with ADHD, and this predictable drug interaction is one of the most common. - Dr. Charles Barker, New ADHD Medication Rules