Impact of a restrictive drug access program on the risk of cardiovascular encounters in children exposed to ADHD medications

BACKGROUND

ADHD medications increase clinical encounters for cardiovascular symptoms. Uncertain are the roles of differences in ADHD medications and restrictive practices by drug programs.

METHODS

We conducted two nested case-control studies. The first was nested within a cohort of children de novo users of methylphenidate, amphetamines or atomoxetine and the second case-control study was nested within a subcohort of de novo amphetamine or atomoxetine users with no cardiovascular events prior to the first dispensing of either drug. The outcome for both studies was the composite of physician visits, emergency room visits or hospitalizations for cardiovascular reasons. Cases were matched on sex, age and date of entry within the cohorts, with up to 10 controls. Patients with an active dispensation of ADHD medications at the index date (and up to 90 days previously) were considered exposed. Conditional logistic regression was used to calculate odd ratios (OR).

RESULTS

The full cohort comprised 38,495 patients. Among these patients, 3595 (9.3%) had no prior cardiovascular events (the subcohort). In the full cohort, an association was demonstrated with exposure to amphetamine and atomoxetine (but not methylphenidate) and the cardiovascular encounter outcomes. When the sub-cohort was analyzed the associations with amphetamine or atomoxetine were no longer evident.

CONCLUSION

Reimbursement policies need to be considered when conducting observational studies. Had the analysis been conducted without consideration of these policies the results would have incorrectly identified amphetamine and atomoxetine as important risk factors for cardiovascular encounters.

Cognitive functioning associated with stimulant use in patients with non-affective psychosis, their unaffected siblings and healthy controls

BACKGROUND

Little is known about the effect of stimulant use (amphetamines, cocaine, ecstasy) on cognitive functioning in schizophrenia patients. The current study examined (1) whether recency and frequency of stimulant use is associated with cognitive functioning and (2) whether these associations differ between psychotic patients, their unaffected siblings and controls.

METHOD

Participants completed a comprehensive cognitive test battery. Stimulant use was assessed by urinalysis and by the Composite International Diagnostic Interview (CIDI). Using random effects regression models, the main effects of Stimulant Use and the interaction with Diagnostic Status on cognitive functioning were assessed.

RESULTS

The interaction term between Stimulant Use and Diagnostic Status was not significant for any of the cognitive outcome variables, indicating similar effects of stimulant use in all three groups. Recent stimulant users showed more errors deficit in verbal learning in comparison to never users (Cohen's d = -0.60, p < 0.005). Lifetime frequent stimulant use was significantly associated with worse immediate and delayed verbal recall, working memory and acquired knowledge (Cohen's d = -0.22 to -0.29, p < 0.005). Lifetime infrequent stimulant use was not associated with significant cognitive alterations in comparison to never use.

CONCLUSIONS

The presence of cognitive deficits associated with lifetime stimulant use is dependent on the frequency of use, with no observed deficits in infrequent users and modest negative effects in frequent users.

The effect of drug use on the age at onset of psychotic disorders in an Australian cohort

BACKGROUND

We aimed to examine the association between illicit substance use and age at onset in psychotic disorders in an Australian cohort.

METHODS

Retrospectively acquired information on substance use during the year prior to illness onset was collected from 1642 participants enrolled in the Australian National 2010 Survey of High Impact Psychosis study (SHIP), with an ICD-10 diagnosis of schizophrenia spectrum or affective psychosis. Latent class analysis was performed according to illicit substance use, using age as an active covariate; identified classes were subsequently validated. Cox regression was used to examine the independent contribution of the identified substance use classes and several confounding variables to the prediction of age at onset of psychosis.

RESULTS

Three classes according to substance use were identified: non-users (n=803), cannabis predominant users (n=582), and polysubstance users (n=257). For participants with schizophrenia spectrum disorders, cannabis predominant users had a higher hazard of earlier age at onset than for non-users (adjusted HR=1.38, 95% CI=1.2-1.6); polysubstance users had an even higher hazard (adjusted HR=1.95, 95% CI=1.5-2.4). In contrast, for participants with affective psychosis, cannabis predominant users (adjusted HR=1.10, 95% CI=0.8-1.4) and polysubstance users (adjusted HR=0.87, 95% CI=0.6-1.3) did not have a higher hazard of earlier age at onset compared with non-users.

CONCLUSIONS

Illicit substance use in the 12 months prior to psychosis onset has a differential effect on age at onset in schizophrenia spectrum and affective psychotic disorders. Our findings are compatible with the notion that illicit drugs bring forward age at onset in schizophrenia spectrum disorders but not affective psychotic disorders.

How long should infants at risk of drug withdrawal be monitored after birth?

AIM

Neonatal abstinence syndrome (NAS) is an increasingly common disorder diagnosed in infants exposed to various drugs, causing immense financial and social burden. Recommendations from various bodies are for babies to be monitored for 4 to 7 days following birth so that prompt treatment can commence should symptoms develop. We aimed to determine the best post-natal observation period in babies at risk of NAS.

METHODS

A retrospective review was undertaken of infants ≥35 weeks' gestation who received treatment for NAS in the period 2001-2010. During this time, the standard post-natal observation period was a minimum of 7 days. Data including drug exposure, day of admission and day of treatment were collected.

RESULTS

Two hundred and ten babies were included. Drug exposure was predominantly to opiates (99%); however, most infants (58%) were exposed to additional substances (benzodiazepines, cannabis or amphetamines). Ninety-five per cent of infants were admitted by day 5 of life. Of the babies treated by day 7, 98.5% had been admitted to the nursery by day 5. Infants with polydrug exposure were admitted significantly earlier; however, time to treatment was not significantly different to those exposed to opiate replacement therapy alone.

CONCLUSIONS

In our hospital, babies treated for NAS often required admission before day 5. This has implications for hospital resource allocation, suggesting that routine post-natal observation for NAS could be shortened to 5 days. Further research is needed to help identify neonates who require more careful post-natal observation.

Caregiver survey of pharmacotherapy to treat attention deficit/hyperactivity disorder in individuals with Williams syndrome

Williams syndrome (WS) is a genetic condition characterized by a unique neurocognitive and behavioral profile, including increased incidence of attention deficit/hyperactivity disorder (ADHD). The purpose of the present study was to examine the perceived helpfulness and side effects of medications used to treat ADHD (methylphenidate class, amphetamine class, atomoxetine) in individuals with WS. This was accomplished with a survey of parents/caregivers of individuals with WS through the Williams Syndrome Association. Five-hundred twelve (512) parents/caregivers responded to the survey regarding their child's/adult child's use of ADHD medications. Twenty-seven percent (27%) of the individuals had been prescribed a medication for ADHD, most commonly a methylphenidate class medication. OROS-methylphenidate was reported as the most helpful methylphenidate class formulation, with 74% reporting it at least somewhat helpful. Survey participants reported similar side effects as typically developing controls, but to a greater degree. Irritability was the most commonly endorsed side effect of an ADHD medication (38%). Individuals reported use of stimulant medications in the presence and absence of underlying cardiac conditions, with 56% of ADHD medication users reporting supravalvular aortic stenosis, 36% pulmonary artery stenosis, and 25% systemic hypertension. Individuals taking ADHD medications were more likely to report dental problems (p=0.004). Additional studies are needed to further investigate these findings and examine short-versus long-acting stimulant medications and dosage effects.

Amphetamines, atomoxetine and the risk of serious cardiovascular events in adults

Main Objective

To compare the incidence rates of serious cardiovascular events in adult initiators of amphetamines or atomoxetine to rates in non-users.

Methods

This was a retrospective cohort study of new amphetamines (n = 38,586) or atomoxetine (n = 20,995) users. Each medication user was matched to up to four non-users on age, gender, data source, and state (n = 238,183). The following events were primary outcomes of interest 1) sudden death or ventricular arrhythmia, 2) stroke, 3) myocardial infarction, 4) a composite endpoint of stroke or myocardial infarction. Cox proportional hazard regression was used to calculate propensity-adjusted hazard ratios for amphetamines versus matched non-users and atomoxetine versus matched non-users, with intracluster dependence within matched sets accounted for using a robust sandwich estimator.

Results

The propensity-score adjusted hazard ratio for amphetamines use versus non-use was 1.18 (95% CI: 0.55–2.54) for sudden death/ventricular arrhythmia, 0.80 (95% CI: 0.44–1.47) for stroke, 0.75 (95% CI: 0.42–1.35) for myocardial infarction, and 0.78 (95% CI: 0.51–1.19) for stroke/myocardial infarction. The propensity-score adjusted hazard ratio for atomoxetine use versus non-use was 0.41 (95% CI: 0.10–1.75) for sudden death/ventricular arrhythmia, 1.30 (95% CI: 0.52–3.29) for stroke, 0.56 (95% CI: 0.16–2.00) for myocardial infarction, and 0.92 (95% CI: 0.44–1.92) for stroke/myocardial infarction.

Conclusions

Initiation of amphetamines or atomoxetine was not associated with an elevated risk of serious cardiovascular events. However, some of the confidence intervals do not exclude modest elevated risks, e.g. for sudden death/ventricular arrhythmia.

Prohibition or coffee shops: regulation of amphetamine and methylphenidate for enhancement use by healthy adults

This article analyzes appropriate public policies for enhancement use of two most important stimulant drugs: Ritalin (methylphenidate) and Adderall (mixed amphetamine salts). The author argues that appropriate regulation of cognition enhancement drugs cannot be a result of a general discussion on cognitive enhancements as such, but has to be made on a case-by-case basis. Starting from the recently proposed taxation approach to cognition enhancement drugs, the author analyzes available, moderately permissive models of regulation. After a thorough analysis of relevant characteristics of methylphenidate and amphetamine, the author concludes that a moderately liberal permissive regulation of enhancement use by healthy adults might be appropriate for extended release forms of methylphenidate. However, due to their danger profile, amphetamine and instant release forms of methylphenidate should not be made readily available to healthy adults and would need to be prohibited.

Illicit stimulant use in humans is associated with a long-term increase in tremor

Use of illicit stimulants such as methamphetamine, cocaine, and ecstasy is a significant health problem. The United Nations Office on Drugs and Crime estimates that 14-57 million people use stimulants each year. Chronic use of illicit stimulants can cause neurotoxicity in animals and humans but the long-term functional consequences are not well understood. Stimulant users self-report problems with tremor whilst abstinent. Thus, the aim of the current study was to investigate the long-term effect of stimulant use on human tremor during rest and movement. We hypothesized that individuals with a history of stimulant use would exhibit abnormally large tremor during rest and movement. Tremor was assessed in abstinent ecstasy users (n = 9; 22 ± 3 yrs) and abstinent users of amphetamine-like drugs (n = 7; 33 ± 9 yrs) and in two control groups: non-drug users (n = 23; 27 ± 8 yrs) and cannabis users (n = 12; 24 ± 7 yrs). Tremor was measured with an accelerometer attached to the index finger at rest (30 s) and during flexion and extension of the index finger (30 s). Acceleration traces were analyzed with fast-Fourier transform. During movement, tremor amplitude was significantly greater in ecstasy users than in non-drug users (frequency range 3.9-13.3 Hz; P<0.05), but was unaffected in cannabis users or users of amphetamine-like drugs. The peak frequency of tremor did not significantly differ between groups nor did resting tremor. In conclusion, abstinent ecstasy users exhibit an abnormally large tremor during movement. Further work is required to determine if the abnormality translates to increased risk of movement disorders in this population.

Motor skills of children newly diagnosed with Attention Deficit Hyperactivity Disorder prior to and following treatment with stimulant medication

Motor difficulties are common in children with Attention Deficit Hyperactivity Disorder (ADHD). Although preliminary evidence has suggested that methylphenidate can improve the motor skills in children with ADHD and Developmental Coordination Disorder (DCD), the effect of stimulant medication on motor performance in children newly diagnosed with ADHD with or without motor impairment remains unclear. A cohort study of 49 medication-naïve children (39 male; mean age 8.4±1.3 years) with ADHD was conducted. Children were evaluated using the Movement Assessment Battery for Children and the developmental test of visual motor integration at diagnosis and again three months following daily treatment with a stimulant medication. Motor difficulties were highly present at baseline (73.5%) but resolved in a subset after treatment with stimulant medication, suggesting that their motor difficulties may be attributed in part to their attentional problems. Nevertheless, motor impairment persisted in 55.1% of the sample. The severity of the behavioural symptoms was significantly associated with balance skills in children without motor impairments (r(2)=0.30, p<0.01) and with visual motor integration skills in children with persisting motor difficulties (r(2)=0.27, p<0.01). Attentional difficulties negatively affect the motor skills of children with ADHD. Following the use of stimulant medication, an important subset continued to demonstrate motor difficulties. The improvement in behaviour was insufficient to resolve motor problems and these children should therefore be targeted for rehabilitation services.

A clinican's guide to adult attention-deficit hyperactivity disorder

While attention-deficit hyperactivity disorder (ADHD) has been traditionally viewed as a childhood ailment, longitudinal data suggest that it persists into adulthood for most affected individuals. Adult ADHD is now recognized as a legitimate diagnosis with clinical and epidemiological implications. It is estimated that 4% of American adults are afflicted by this disorder. There have been advances in adultADHD screening tools, diagnostic guidelines, medication delivery systems and psychosocial treatments. Despite these gains, there is great variability among clinicians in the diagnosis and treatment of adult ADHD. This article reviews controversies surrounding the diagnosis and treatment of adult ADHD and suggests strategies to overcome existing obstacles.

The return of rainbow diet pills

The US Food and Drug Administration (FDA) has recently warned consumers about the risks of weight loss supplements adulterated with multiple pharmaceutical agents. Some of these supplements combine potent anorectics, such as amphetamines derivatives, with benzodiazepines, beta-blockers, and other medications to suppress the anorectics' adverse effects. These weight loss supplements represent the most recent generation of rainbow diet pills, named for their bright and varied colors, which date back more than 70 years. Beginning in the 1940s, several US pharmaceutical firms aggressively promoted rainbow pills to physicians and patients. By the 1960s the pills had caused dozens of deaths before the FDA began removing them from the US market. We used a variety of original resources to trace these deadly pills from their origins in the United States to their popularity in Spain and Brazil to their reintroduction to the United States as weight loss dietary supplements.

Do prescription stimulants increase the risk of adverse cardiovascular events?: A systematic review

BACKGROUND

There is increasing concern that prescription stimulants may be associated with adverse cardiovascular events such as stroke, myocardial infarction, and sudden death. Public health concerns are amplified by increasing use of prescription stimulants among adults.

METHODS

The objective of this study was to conduct a systematic review of the evidence of an association between prescription stimulant use and adverse cardiovascular outcomes. PUBMED, MEDLINE, EMBASE and Google Scholar searches were conducted using key words related to these topics (MESH): ADHD; Adults; Amphetamine; Amphetamines; Arrhythmias, Cardiac; Cardiovascular Diseases; Cardiovascular System; Central Nervous Stimulants; Cerebrovascular; Cohort Studies; Case-control Studies; Death; Death, Sudden, Cardiac; Dextroamphetamine; Drug Toxicity; Methamphetamine; Methylphenidate; Myocardial Infarction; Stimulant; Stroke; Safety. Eligible studies were population-based studies of children, adolescents, or adults using prescription stimulant use as the independent variable and a hard cardiovascular outcome as the dependent variable.

RESULTS

Ten population-based observational studies which evaluated prescription stimulant use with cardiovascular outcomes were reviewed. Six out of seven studies in children and adolescents did not show an association between stimulant use and adverse cardiovascular outcomes. In contrast, two out of three studies in adults found an association.

CONCLUSIONS

Findings of an association between prescription stimulant use and adverse cardiovascular outcomes are mixed. Studies of children and adolescents suggest that statistical power is limited in available study populations, and the absolute risk of an event is low. More suggestive of a safety signal, studies of adults found an increased risk for transient ischemic attack and sudden death/ventricular arrhythmia. Interpretation was limited due to differences in population, cardiovascular outcome selection/ascertainment, and methodology. Accounting for confounding and selection biases in these studies is of particular concern. Future studies should address this and other methodological issues.

Acute myocardial infarction in a teenager due to Adderall XR

Adderall XR is commonly prescribed for children and adolescents with attention deficit/hyperactivity disorder. We present a case of a 15-year-old male who suffered a myocardial infarction after starting Adderall XR. Patient was otherwise in good health with no previous cardiac abnormalities. Cardiac catheterization was normal, and etiology was presumed to be secondary to acute vasospasm. The patient improved with cessation of medication. Physicians need to carefully screen patients for cardiac abnormalities prior to starting amphetamine-based medications.

The nonmedical use of prescription stimulants among dental and dental hygiene students

The purpose of this study was to determine the nonmedical use of prescription attention deficit disorder (ADD) stimulant medication among dental and dental hygiene students. A questionnaire was used to examine demographic information, student experiences, and perceptions of prescription stimulant medication and to determine if students used a prescription stimulant nonmedically. In 2008, 401 surveys were mailed to dental education institutions in the south-central region of the United States, and 243 surveys (61 percent) were returned. The survey found that 12.4 percent of these students used a prescription stimulant nonmedically and, of those, 70 percent took it to improve attention and/or concentration. The most commonly reported stimulant medication used nonmedically was Adderall (77 percent). The majority (87 percent) of the students obtained the medication through friends, and 90 percent began using the drug in college. Even though 74 percent of the students reported being stressed, chi-square analysis found no significant association between nonmedical use of ADD stimulant medication and stress level (p=0.585). Sixteen percent of the students surveyed felt it was easy to obtain stimulant medication for nonmedical use at their school, and 17 percent thought it was a problem within their institution. These results may help administrators and faculty members become aware of potential problems with the misuse of ADD stimulant medication.

Characteristics of college students with attention-deficit hyperactivity disorder symptoms who misuse their medications

OBJECTIVE

The purpose of the current investigation is to examine the characteristics of college students with attention-deficit hyperactivity disorder symptoms who misuse their prescribed psychostimulant medications.

METHODS AND PARTICIPANTS

Forty-three undergraduate students with a prescription for Ritalin or Adderall completed structured interviews and a battery of questionnaires.

RESULTS

Analyses revealed that compared to non-misusers, misusers were significantly more likely to report using a greater number of illicit substances, including nicotine, marijuana, cocaine, hallucinogens, and opiates, over the past year. Additionally, compared to non-misusers, misusers were significantly more likely to report greater negative expectancies effects, experience more hyperactivity symptoms, and score higher on a measure of sensation seeking.

CONCLUSION

The findings have important implications for future prevention initiatives. In particular, knowledge regarding the extent of misuse in populations with and without prescriptions and variables associated with misuse is essential to the development of effective prevention programs.

Khat use and neurobehavioral functions: suggestions for future studies

Although there is a rich body of research available regarding the effect of acute and chronic khat dosing in animal models, research on the behavioral and cognitive effects of khat in human subjects is not extensive and several of the available studies have been done only in the context of observational and single-case studies. In light of the absence of a substantial literature on the neurobehavioral deficits associated with khat use and to provide a context that could be used to identify themes for future research we review previous research that has focused on other stimulant drugs. This review highlights multiple areas of neurocognitive deficit that have been identified in previous studies of individuals who have been chronic users of stimulants, such as amphetamines and methamphetamines. The review highlights a substantial body of evidence demonstrating a wide range of learning and memory impairments including deficits that persist during abstinence from active drug use. This review does not imply a similar khat effect, but due to some similarities pharmacologically between the active components of khat (cathinone and cathine) and amphetamines, future studies examining these same domains of cognitive functioning in chronic khat users and abstinent khat users appears to be warranted, if possible using some of the same or similar laboratory measures.

Drugs of abuse and human placenta

Drugs of abuse such as cocaine and amphetamines, when used by pregnant women, exert deleterious effects on the fetus. These drugs produce their effects through inhibition of the serotonin transporter, norepinephrine transporter, and dopamine transporter. The inhibition can occur in the pregnant mother as well as in the fetus. These events contribute to the detrimental effects of these drugs on the fetus. However, the role of placenta, which serves as the link between the pregnant mother and the fetus, in the process remains understudied. It has been assumed that the placenta did not play any direct role in the process except that it allowed the passage of these drugs from maternal circulation into fetal circulation. This was before the discovery that the placenta expresses two of the three monoamine transporters. The serotonin transporter and the norepinephrine transporter are expressed on the maternal-facing side of the syncytiotrophoblast, thus exposed to the inhibitory actions of cocaine and amphetamines if present in maternal blood. Inhibition of these transporters in the placenta could lead to elevation of serotonin and norepinephrine in the intervillous space that may cause uterine contraction and vasoconstriction, resulting in premature delivery, decreased placental blood flow, and intrauterine growth retardation. Thus, the placenta is actually a direct target for these abusable drugs. Since the placental serotonin transporter and norepinephrine transporter are also inhibited by many antidepressants, therapeutic use of these drugs in pregnant women may have similar detrimental effects on placental function and fetal growth and development.

The mixed amphetamine salt extended release (Adderall XR, Max-XR) as an adjunctive to SSRIS or SNRIS in the treatment of adult ADHD patients with comorbid partially responsive generalized anxiety: an open-label study

To examine the changes in partially responsive anxiety symptoms utilizing adjunctive treatment with the mixed amphetamine salt extended release (Adderall XR, MAX-XR) in the treatment of adult ADHD patients, with comorbid refractory anxiety. Consenting adult patients (n = 32) with confirmed diagnosis of generalized anxiety (GA) and comorbid (ADHD) participated in this open-label study. All patients had significant comorbid anxiety symptoms (HAM-A > 7) and failed to respond to 8-week trials of Serotonin Reuptake Inhibitors (SSRIs) or Norepinephrine Reuptake inhibitors (SNRIs). All patients were treated with the "Mixed Amphetamine salts Extended Release Adderall XR, (MAS-XR), as adjunctive to SSRIs or to SNRIs and were followed for at least 12 weeks. The primary effectiveness measure was the Clinical Global Impression severity subscale (CGI-S). Other scales included the Hamilton Anxiety Scale (HAM-A), the adult ADHD Self-Report Scale (ASRS-v1.1) symptom checklist, and Sheehan's disability scale. Baseline measures prior to the treatment with MAS-XR were compared to those at 4, 8, and at 12 weeks of treatment. Monitoring for pulse, blood pressure, and weight changes was carried out at baseline and at end point. All patients completed this open-label trial. There was significant and robust resolution of symptoms of all effectiveness measures, including the symptoms of anxiety, as shown by changes from baseline in HAM-A, ASRS-v1.1, and CGI at 8 weeks. Also there was significant reduction in the disability score at 12 weeks. Patients tolerated the treatment, and there were no significant cardiovascular changes at 12 weeks. There was decrease in mean weight at 12 weeks by 2.2 kg (P < .001). Mixed amphetamine salts MAS-XR can be used in adult patients with ADHD and comorbid anxiety symptoms. Larger controlled studies are needed to support the effectiveness of mixed amphetamine salts in patients with comorbid anxiety symptoms. Treatments need to include the targeting of the ADHD symptoms effectively in order to achieve better resolution of anxiety symptoms.