Sudden Unexplained Death
Summary: There appears to be no difference between the rate of sudden unexplained death (SUD) in the general population and the rate among people taking stimulants at therapeutic dose levels. The reported incidents of SUD among those taking stimulants are almost exclusively among patients with a pre-existing heart condition or a history of a blood relative who had experienced SUD.
Over 55,000 children between 3 and 20 years of age who were newly diagnosed with ADHD were followed up for a number of years. Some never took stimulants, some took stimulants but stopped, and some continued to take stimulants. Each group averaged about the same number of years of follow up. Two cardiac deaths occurred in the group that never took stimulants, three cardiac deaths occurred among former users, and no deaths occurred among current users. The fact that there is no significant difference between the groups is reassuring for those taking stimulants.
On the other hand, current stimulant users were about 20% more likely to visit the ER for cardiac causes than were non-users. This is not surprising since stimulants not infrequently increase pulse and blood pressure. However, the authors of this study do not report whether the increase in ER visits was related to
- the use of other drugs by those taking stimulants
- a greater level of anxiety among those taking stimulants, or
- cardiac disease or cardiac symptoms
The study was reported in the journal Pediatrics in December 2007.
Several years ago, both Health Canada and the US Food and Drug Agency reviewed the studies of sudden unexplained death (SUD) among ADHD patients taking stimulants and found no convincing connection between use of stimulants and elevated rates of SUD.About 1 in 27,000 people in the US will experience SUD each year. That means that, of every 2 million people, 74 die suddenly each year for no apparent reason – whether they are taking stimulants or not. So if 100 of the 3 million people taking stimulants experience SUD each year, that would not be evidence that stimulants cause SUD. The number of deaths each year of people taking stimulants would have to be considerably larger to be statistically significant, and it is not known to be.
Still, studies have found that almost half of the people taking stimulants who experienced sudden unexplained death had a pre-existing heart problem, often not previously recognized, or a family history of unexplained death at an early age. To me that means that people who have heart problems or have a blood relative who died young for no apparent reason should be wary of taking stimulants, which are known to increase the heart rate and blood pressure and alter the heart rhythm in some people. If stimulants are strongly indicated, it would be prudent to get a consultation from a cardiologist before deciding to start them.
Early in the summer of 2009, a study published in the American Journal of Psychiatry reported that children who experienced SUD were more likely to have been taking stimulants than children who were not. While provocative, this doesn’t tell whether stimulants caused the SUD.
Imagine a study that showed that men who died of a heart attack were much more likely to have brown lawns than men who didn’t have a heart attack. Men living in areas where the summer sun is really hot have more heart attacks – and brown lawns – but the brown lawns do not cause the heart attacks. Similarly, because stimulants were associated in the study with SUD, it is tempting to conclude that they caused the deaths.
But the higher rate of SUD among known stimulant users could have been caused by a number of other factors – for example, post-mortem blood levels of stimulants are much less likely to be done on passengers in an auto accident than on people known to be taking stimulants. So an unknown number of passengers who were stimulants users may have been missed. An association can be an important clue or a coincidence or a very misleading clue (as it is with the brown lawns). Associations should not be used as the basis for conclusions.
In balancing the risks and benefits of stimulants for people with ADD, it is also worth keeping in mind that people who have ADD and who don’t take stimulants may be at a higher risk of sudden death than the general population as they are more likely than others to engage in high risk behaviors including unsafe sex, are more impulsive, have more automobile and other accidents, and engage more in substance abuse. Most of these risks have been shown to be reduced by the use of stimulants.
Hopefully more research will bring make it clear how much stimulants increase (or decrease) the incidence of sudden death. Still, if there is a chance of sudden cardiac death from stimulants, what can be done to minimize it? The risk of SUD in pediatric patients taking stimulants is probably comparable to the risk of SUD among students taking part in athletic activities. While this risk is low, it may be reduced further by the doctor…
- taking a careful medical history of the patient and his or her biological family especially with regard to heart problems, brain disorders, fainting, seizures, and SUD of a blood relative at an early age
- doing a physical exam at baseline and, if physical problems arise later, during treatment
- asking the patient to notify him or her if cardiac symptoms such as unexplained chest pain, fainting, and palpitations appear
- where there is a family history of heart problems early in life, it would be reasonable to obtain an EKG and a cardiac consultation since there may be a heart problem that is not obvious.
- encouraging the patient tn engage in regular physical activity
- unless contraindicated, encouraging the patient to take very low daily doses of aspirin, around 40mg/day (half a baby aspirin a day or one every other day).
In many European countries, EKG screening for all student athletes participating in organized sports is mandatory. Studies in Japan have shown that EKG’s are more sensitive to cardiac abnormalities than are a medical history and physical exam, and universal screening of school children for cardiovascular disease has been mandatory since 1973.