Archive for September, 2013

ADHD in People Age 50 and older

In the September issue 2013 of Attention Magazine, published by the national organization CHADD (Children and Adults with ADHD), my article was published on ADHD in people age 50 and older. There is remarkably little research looking at this population of patients. Clinical medication trials that seek the FDA approval for the treatment of ADHD include subjects up to 65 years old. However, the number of subjects over 50 in these studies is relatively small and often the mean age is 34.

Unfortunately, ADHD may not be a diagnostic consideration when older people complain of cognitive difficulties. A study looking at memory clinics in the U.S. found only 1 in 5 centers screen for ADHD. Therefore, it is possible that ADHD symptoms may be misdiagnosed as something else (Fischer BL 2012). Given that ADHD is a cognitive impairment, people wonder if ADHD is a risk factor for developing dementia. A recently published study looking at the question concluded that ADHD is not a risk factor for dementia (Ivanchak N, 2011). We’ll await further research.

Myths about ADHD over age 50:

Can’t diagnose ADHD in the presence of older age.

Can’t diagnose ADHD in the presence of medical disorders and medications.

Why bother treating it, they lived their whole life this way.

The ADHD medications aren’t safe in older adults.

Diagnosing ADHD in a person this age presents unique challenges because there are specific medical and psychiatric considerations in someone over age 50. If we just focus on the cognitive symptoms, the first issue is how much of the cognitive symptoms are age related. As we age we will notice some forgetfulness, difficulty in recalling information quickly, losing a train of thought, and getting distracted. What distinguishes this from ADHD is the fact that the symptoms started much later in life and not in childhood. Second possibility is a new diagnostic category in the DSM-5 called Mild Cognitive Impairment. This is a degree of cognitive change accompanied by impairment but not rising to the level of Alzheimer’s disease. Third are the effects of medication on cognition. As we age we will develop medical illnesses treated with medication that may have subtle effects on cognition (i.e. statins, antidepressants, chemotherapy).  The more medications we are on, the more likely they will affect our thinking ability. Fourth, medical illnesses themselves may affect our thinking ability (i.e. hypothyroidism, post cardiac surgery). Fifth, women in peri- or post-menopause often notice clear changes in memory and cognition. Sixth, a long history of alcohol and/or substance abuse may cause lasting cognitive symptoms. Seventh, head trauma/concussion/neurological disorders may leave persistent changes on memory and processing speed for information (i.e. multiple concussions from sports injury).  What distinguishes all of the above diagnostic consideration is the age of onset of these symptoms. Except for the possibility of head trauma in childhood, all the other diagnostic considerations occur later in life. The hallmark of ADHD is the presence of symptoms in childhood.

I will continue my blog on this subject in the future. Thank you for your interest. Hope it is helpful to you.

Latest generic Concerta may not work as well as others

Recently, a new generic of Concerta, manufactured by Mallinckrodt, has come to market and patients may be getting this substitute for their prescription. I have  two patients who, having been on the previous generic manufactured by Watson, now say this new generic is clearly not working as well. One of my patients took the pills back to the local pharmacist who is reported to have said “I have several people who have come back complaining ‘It’s not working.'”.

Background: Brand Concerta pill contains a mechanism called “OROS” to deliver the methylphenidate over several hours at an increasing dose over time. The benefit of this specific delivery was established in sophisticated research. The Mallinckrodt generic does not and can not use this technology because of patents. This is not to say that an equivalently effective medication can’t be developed without OROS. It just appears that the Mallinckrodt formulation may not be equally effective to the Watson formulation in some patients.

I bring this to clinicians’ and peoples’ attention for two clinical reasons:

1. If you have been on other preparations of Concerta and now find the medication is not working well for you. Check the manufacturer with your pharmacist. He/she will want to know.

2. If you are prescribed Concerta for the first time, receive a generic, and you find it doesn’t work well, even at higher doses, check the manufacturer. Don’t rule out Concerta as an effective medication because of this experience. See if you can specifically request the Watson formulation from the pharmacist.

Hope this is helpful. I’ll be watchful and interested to see how this develops. Please leave comments for me. Thanks.

High Dose Stimulant Treatment for Adult ADHD

All ADHD medications that are FDA approved to treat adults have designated maximum daily doses. It is important to understand how these daily maximum doses are determined in order to consider higher doses beyond these thresholds.  The FDA receives the clinical registration trial research and it makes a determination of maximum daily dose based on the presented data. If, for example, a clinical trial had a maximum dose of 50 mg a day then the FDA will only approve the drug with a maximum daily dose of 50 mg.  An example of this is Vyvanse where the trial looked at 30 mg, 50 mg and 70 mg a day. Maximum daily dose approved is 70 mg.

In some cases where the clinical trial evaluated several doses, the FDA may only approve a maximum dose in the middle dose range from the trial because the higher dose didn’t demonstrate a statistically significant difference in effect. Case in point, Concerta maximum daily dose in the package information is 72 mg, although the U.S. adult trial went to 108 mg a day. However the trial protocols are not designed to answer the question “If you don’t respond to 72 mg a day, will you respond to 108 mg a day”.

Where am I going with this? I have several patients at what would be considered as very high doses of stimulant medication-methylphenidate 400 mg a day, Vyvanse 200 mg a day. Unsafe? Well neither patient complains of problematic side effects for which they would stop the medication. Also, blood pressure and pulse are in normal range. We got to these doses because lower doses didn’t have any effect until we went higher. In each of these cases, I have ordered stimulant blood levels to see if blood levels were too high. In fact, in each case the levels were lower that what was expected by mathematical extrapolation.

The point? There are a group of ADHD adults who are very fast metabolizers who will only respond to very high stimulant doses. Since most of the metabolism of amphetamines and methylphenidate occurs outside the liver, I’m not sure obtaining a liver P450 enzyme profile to determine metabolism will be useful.

If you have ADHD and have not responded to appropriate stimulant doses, then consider seeing an ADHD adult psychiatrist who has experience and comfort with this dosing concept.  That’s what true expert clinicians are for.