[Cardiovascular risks and management during Attention Deficit Hyperactivity Disorder treatment with methylphenidate]

Methylphenidate-Induced Non-ischemic Heart Failure With Reduced Ejection Fraction and Mild Pulmonary Hypertension

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that is commonly diagnosed during childhood. Patients present with hyperactive-impulsive behavior and/or inappropriate inattention which may persist through adulthood. Central nervous system stimulants have been used to manage patients with ADHD. Methylphenidate which is used as a first-line therapy has been shown to have adverse cardiovascular effects in these patients. This is a case of a young male with a history of ADHD since childhood on methylphenidate who was diagnosed with acute non-ischemic heart failure with an ejection fraction of 15-20%. Methylphenidate-induced heart failure is the rare adverse effect seen in ADHD patients who are on this medication. Our patient was started on goal-directed medical therapy for heart failure and was discharged with an implantable cardioverter defibrillator (LifeVest®, ZOLL, Pittsburgh, PA) because of his persistently low left ventricular ejection fraction. It is important for physicians to always consider heart failure as a possible cardiovascular adverse effect when starting patients on methylphenidate for the management of ADHD.

Association between methylphenidate and risk of myocardial infarction: A multinational self-controlled case series study

PURPOSE

To investigate the association between use of methylphenidate and risk of myocardial infarction among Asians.

METHODS

We conducted a multinational self-controlled case series study using nationwide healthcare databases of South Korea (2002-2018), Taiwan (2004-2015), and Hong Kong (2001-2016). Of patients with myocardial infarction who were also prescribed methylphenidate within the observation period, methylphenidate use was classified into four mutually exclusive periods by each person-day: exposed (exposed to methylphenidate), pre-exposure (prior to the first methylphenidate prescription), washout (after the end of methylphenidate treatment), and baseline (unexposed to methylphenidate). Risk of myocardial infarction among the three periods of methylphenidate use was compared to the baseline period using conditional Poisson regression analysis to estimate incidence rate ratios (IRRs) with 95% confidence intervals (CIs).

RESULTS

We identified 2104, 484, and 30 patients from South Korea, Taiwan, and Hong Kong, respectively. Risk of myocardial infarction was the highest during the pre-exposure period in all three populations: South Korea, pre-exposure (IRR 3.17, 95% CI 3.04-3.32), exposed (1.05, 1.00-1.11), washout (1.92, 1.80-2.04); Taiwan, pre-exposure (1.97, 1.78-2.17), exposed (0.72, 0.65-0.80), washout (0.56, 0.46-0.68); Hong Kong, pre-exposure (18.09, 8.19-39.96), exposed (9.32, 3.44-25.28), washout (7.69, 1.72-34.41). Following stratification for age and sex, the trends remained analogous to the main findings across all three populations.

CONCLUSIONS

Although a positive association between initiating methylphenidate and the onset of myocardial infarction was observed, the risk was the highest in the period before its initiation. Thus, this multinational study suggests there was no causal relationship between methylphenidate and myocardial infarction among Asians.

A randomized controlled laboratory study on the long-term effects of methylphenidate on cardiovascular function and structure in rhesus monkeys

BACKGROUND

Whether long-term methylphenidate (MPH) results in any changes in cardiovascular function or structure can only be properly addressed through a randomized trial using an animal model which permits elevated dosing over an extended period of time.

METHODS

We studied 28 male rhesus monkeys (Macaca mulatta) approximately 7 years of age that had been randomly assigned to one of three MPH dosages: vehicle control (0 mg/kg, b.i.d., n = 9), low dose (2.5 mg/kg, b.i.d., n = 9), or high dose (12.5 mg/kg, b.i.d., n = 10). Dosage groups were compared on serum cardiovascular and inflammatory biomarkers, electrocardiograms (ECGs), echocardiograms, myocardial biopsies, and clinical pathology parameters following 5 years of uninterrupted dosing.

RESULTS

With the exception of serum myoglobin, there were no statistical differences or apparent dose-response trends in clinical pathology, cardiac inflammatory biomarkers, ECGs, echocardiograms, or myocardial biopsies. The high-dose MPH group had a lower serum myoglobin concentration (979 ng/mL) than either the low-dose group (1882 ng/mL) or the control group (2182 ng/mL). The dose response was inversely proportional to dosage (P = .0006).

CONCLUSIONS

Although the findings cannot be directly generalized to humans, chronic MPH exposure is unlikely to be associated with increased cardiovascular risk in healthy children.

Stimulants and Pediatric Cardiovascular Risk

OBJECTIVE

Concerns about serious cardiovascular (CV) events among stimulant-treated youth have led to clinical and policy debates. Accordingly, several population-based empirical studies have assessed the risk of CV events in children and adolescents treated with stimulants. The main objective of this review was to summarize findings and to evaluate the strengths and weaknesses of these population-based studies. In addition, we discuss the CV monitoring and policy implications for a clinically focused audience.

METHODS

A computerized literature search of Medline and PsycINFO was conducted for the calendar years 1990-2015 to identify population-based studies assessing stimulant treatment-emergent CV events in youth. Additional reports, peer-reviewed or gray literature, for example, government reports, were also included.

RESULTS

Nine population-based studies (one case-control and eight retrospective cohort designs) were included in this review. The case-control study compared sudden unexplained death cases to age-matched controls (motor vehicle passenger deaths) with respect to prior stimulant use and found a significant association (odds ratio = 7.4 [95% CI: 1.4-74.9]). By contrast, most retrospective cohort studies assessed the risk of serious CV events (i.e., sudden death, myocardial infarction, and stroke) and did not find an association with current stimulant exposure. The absolute rate for these serious events was low, but other data support risk. For example, cardiac-related emergency department visits showed a 20% increased risk for current stimulant users compared with nonusers in one study, and another study showed a 64% and 90% increased risk for concurrent use of stimulants with antidepressants and antipsychotics, respectively. Similarly, in another study, compared with nonusers, stimulant users had twofold greater odds of CV-related inpatient or outpatient services.

CONCLUSION

In the face of mixed results from population-based safety studies, this review supports the inclusion of baseline and ongoing monitoring of cardiac status to assure a favorable benefit risk profile for stimulant users, particularly in concomitant regimens with antipsychotics and antidepressants.

STEMI Secondary to Coronary Vasospasm: Possible Adverse Event of Methylphenidate in a 21-Year-Old Man with ADHD

Methylphenidate (Ritalin^®) is an increasingly used medication in the treatment of attention-deficit hyperactivity disorder (ADHD). Cardiovascular adverse effects like vasospasm or myocardial infarction are described as very rare adverse effects. We present the case of a 21-year-old man diagnosed with ADHD who recently started therapy with Ritalin^® Adult 20 mg for at least 3 days. Afterwards he presented with chest pain, elevated troponin and creatine kinase, and posterolateral ST elevations. A myocarditis was initially supposed. In the coronary angiography, signs of coronary artery spasm could be found. The echocardiography showed mild left ventricular dysfunction; no acute myocarditis could be found in the cardiac MRI and myocardial biopsy. The medication with methylphenidate was stopped, and after 12 days the asymptomatic patient was discharged from hospital.

Cardiovascular safety of methylphenidate among children and young people with attention-deficit/hyperactivity disorder (ADHD): nationwide self controlled case series study

OBJECTIVE

 To determine whether treatment with methylphenidate in children and young people with attention-deficit/hyperactivity disorder (ADHD) was associated with cardiovascular events.

DESIGN

 Self controlled case series analysis.

SETTING

 Nationwide health insurance database, 1 January 2008 to 31 December 2011, in South Korea.

PARTICIPANTS

 1224 patients aged ≤17 who had experienced an incident cardiovascular event and had had at least one incident prescription for methylphenidate.

MAIN OUTCOME MEASURES

 A recorded diagnosis (either a primary or secondary cause) of any of the following cardiovascular adverse events: arrhythmias (ICD-10 (international classification of diseases, 10th revision) codes I44, I45, I47, I48, I49), hypertension (codes I10-I15), myocardial infarction (code I21), ischemic stroke (code I63), or heart failure (code I50). Incidence rate ratios were calculated with conditional Poisson regression and adjusted for time varying comorbidity and comedication.

RESULTS

 Increased risk of arrhythmia was observed in all exposed time periods-that is, periods of treatment with methylphenidate-(incidence rate ratio 1.61, 95% confidence interval 1.48 to 1.74), and the risk was highest in the children who had congenital heart disease. No significant risk of myocardial infarction was observed for all exposed time periods (1.33, 0.90 to 1.98), though risk was higher in the early risk periods between eight and 56 days after the start of treatment with methylphenidate. No significant increased risk was observed for hypertension, ischemic stroke, or heart failure.

CONCLUSION

 The relative risk of myocardial infarction and arrhythmias is increased in the early period after the start of methylphenidate treatment for ADHD in children and young people. Though the absolute risk is likely to be low, the risk-benefit balance of methylphenidate should be carefully considered, particularly in children with mild ADHD.

Changes of Heart Rate Variability during Methylphenidate Treatment in Attention-Deficit Hyperactivity Disorder Children: A 12-Week Prospective Study

PURPOSE

The aim of this study was to clarify the relationship between the autonomic nervous system and attention deficit hyperactivity disorder (ADHD) rating scales and to evaluate the usefulness of heart rate variability (HRV) as a psychophysiological biomarker for ADHD.

MATERIALS AND METHODS

Subjects were recruited from outpatients in the Department of Child and Adolescent Psychiatry at the Korea University Medical Center from August 2007 to December 2010. Subjects received methylphenidate. Time- and frequency-domain analyses of HRV, the Korean ADHD rating scale (K-ARS), and computerized ADHD diagnostic system were evaluated before treatment. After a 12-week period of medication administration, we repeated the HRV measurements and K-ARS rating.

RESULTS

Eighty-six subjects were initially enrolled and 37 participants completed the 12-week treatment and HRV measurements subsequent to the treatment. Significant correlations were found between the K-ARS inattention score and some HRV parameters. All of the HRV parameters, except the standard deviations of the normal-to-normal interval, very low frequency, and low frequency to high frequency, showed a significant positive correlation between baseline and endpoint measures in completers. High frequency (HF) and the square root of the mean squared differences of successive normal-to-normal intervals (RMSSD), which are related to parasympathetic vagal tone, showed significant decreases from baseline to endpoint.

CONCLUSION

The HRV test was shown to be reproducible. The decrease in HF and RMSSD suggests that parasympathetic dominance in ADHD can be altered by methylphenidate treatment. It also shows the possibility that HRV parameters can be used as psychophysiological markers in the treatment of ADHD.

Assessment of potential cardiovascular risks of methylphenidate in comparison with sibutramine: do we need a SCOUT (trial)?

With the recent approval of methylphenidate (MPH) for treating attention-deficit/hyperactivity disorder (ADHD) in adults, the number of patients exposed will increase tremendously. The ongoing debate on the cardiovascular safety of MPH has triggered two large retrospective cohort studies in children and adolescents as well as in young to middle-aged adults. These studies looked into serious cardiovascular events (sudden cardiac death, acute myocardial infarction and stroke) as primary endpoints and concluded that MPH was safe after a mean duration of 2.1 years of follow-up in children and adolescents and mean duration of 0.33 years of current use in adults. The results are encouraging with respect to the short- and medium-term use of MPH. Without the inherent limitations of retrospective cohort studies, a prospective randomized, double-blind, placebo-controlled, multicenter trial in individuals stratified for cardiovascular risk factors would allow for an optimized risk assessment. With many millions of patients treated per year and drawing parallels to the lately discovered risks of sibutramine, another sympathomimetic with an overlapping mode of action and similar side effects on heart rate and blood pressure, we hypothesize that such a trial might be a dedicated risk mitigation strategy for public health. A critical assessment of cardiovascular side effects of MPH appears particularly warranted, because ADHD is associated with obesity, smoking and poor health in general. We summarize recent findings with the focus on cardiovascular risks of MPH in humans; we additionally analyze the limited number of rodent studies that have addressed cardiovascular risks of MPH.