DOSING OF ADHD MEDICATIONS

Questions are sometimes raised about exceeding the maximum recommended doses of medications used to treat ADHD. I have reviewed the research studies for these medications and it is clear that the studies were to determine efficacy and were not dosing studies.  Specific doses were chosen to assess the benefit and minimize risk of side-effects.  Once efficacy was determined the study ended and there was no motivation to do further studies addressing the range of doses that were therapeutic. Thus, doses involved in efficacy studies can be mistakenly seen as being studies to determine limits of what is therapeutic. The studies could not recommend a different dose because they did not assess different [higher] doses.  Also, each person is unique and this uniqueness can include how they respond to medications with some people responding to higher doses and others to lower doses. The U.S. Food and Drug Administration recognizes this when they state “the dosing regimen [for stimulant and related medications] is adjusted according to a patient’s individual response to pharmacotherapy."

I believe that it is important to work with my patients to assess their response to medications and in collaboration with them determine an optimal dose. At times this dose may be higher than is “recommended.”  I hope that it is clearer now why this is the case and why it is necessary to prescribe higher doses for these patients.

LITHIUM FOR PTSD: A LITTLE BIT GOES A LONG WAY

For a couple of years I have been prescribing low doses of lithium carbonate to help people with PTSD [post traumatic stress disorder] not react as much to past traumatic experiences when they are recalled.  Those who respond report feeling less anxious and less reactive when they think about past stressful events. It is like they are not as on guard and overall more able to experience events throughout the day without having to react with anxious feelings and a need to be vigilant.  

Unfortunately it has been hard to determine a range of optimal dosing as many of my patients do not respond to the lowest lithium carbonate dose of 150 mg [in a capsule]. Therefore, I have started prescribing a liquid form of lithium to see if a dose range from 6 mg to 120 mg would be helpful. I am also prescribing compounded doses of lithium. Once my patients respond to a specific dose range, I ask them if they are willing to change their doses to see if a small change leads to improvement and then seeing if their most positive response is replicable with repeated trials. This can lead to important information about the range of optimal dosing for lithium in treating PTSD.