Maya E. Guglin, MD, PhD

I never thought about these drugs as potential causes of amphetamine-induced cardiomyopathy, but if you think about it, it makes perfect sense. When we look at causes of cardiomyopathy in the adult population, the most common is ischemic heart disease or coronary heart disease, which is easy to rule out or in. But in about 50% of cases, we find normal or near-normal coronary arteries, and we look for other causes such as prior exposure to anthracyclines, or peripartum cardiomyopathy or a history of myocarditis that degenerated into cardiomyopathy. With the current level of addiction in the U.S. adult population, we also screen for substance abuse, and one of the substances we look for is methamphetamines, because they have catecholamine-mediated effects on the body, which can induce tachycardia, high blood pressure, vasoconstriction and direct toxic cardiac effects. That means people who use methamphetamines are prone to cardiomyopathy, and methamphetamines are a well-established etiology of cardiomyopathy. In about 50% of cases, the cardiomyopathy is reversible if the patient quits methamphetamines, but it is not easy to get off them. So, it makes perfect sense that people who use amphetamines on a chronic basis can have increased risk for developing cardiomyopathy.

I applaud the authors for coming up with this hypothesis, because ADHD is so common and prescription medications for it are frequently used on a chronic basis; some of the patients in this study were on the medication for 10 years. When such chronic use accumulates year after year, it is logical to suggest that we will find some increased rate of incidence of cardiomyopathy.

I am biased, but the diagnosis of ADHD did not exist where I grew up, so I think physicians prescribe these medications to young people way too liberally. I would try harder to use behavioral changes or other social factors to influence children and teenagers before putting them on prescription medications. I understand that many people may disagree. But anything that interferes with your psyche or cortical activity to me is highly undesirable, especially in young people before all their neurological processes and ways of dealing with difficulties in life are completely formed. I would probably be more careful and cautious prescribing these medications, especially for such a lengthy amount of time. The difference between the risk over 1 year and the risk over 10 years is quite big. For a short amount of time, it is probably not such a big deal because the risk is minimal.

In medicine, we very easily put people on a medication but very reluctantly discontinue it even after the need for it is questionable or gone. In many cases, polypharmacy becomes a burden and no one has bothered to critically assess a patient’s medication list and discontinue the unnecessary ones. I would caution physicians who deal with these medications for this population to consider the potential side effects.

Cardiomyopathy is rare, but it is a very serious and life-changing diagnosis, and it may not be reversible. Therefore, I would avoid these medications for this population as much as possible, though I understand why people would think the risk is small enough to be acceptable.