Case Report: High-Dose Methylphenidate for Adult ADHD

Case Report: High-Dose Methylphenidate for Adult ADHD
Case Report: High-Dose Methylphenidate for Adult ADHD

Attention deficit hyperactivity disorder (ADHD), once thought to exclusively affect children and adolescents, is not "outgrown" when children become adults; indeed, about two-thirds of children diagnosed with ADHD continue to experience its symptoms in adulthood.1,2 In children, the core symptoms of the disorder are inattention (distractibility), hyperactivity, and impulsivity. Symptoms change with the advent of adulthood, with a decrease in hyperactivity. But inattention, impulsivity, and disorganization remain present, causing impairments in functioning both in domestic and in employment/academic settings.3 Adults with ADHD generally have lower incomes, greater difficulties in personal relationships, more instability in employment and academics, and higher rates of car accidents.3

ADHD is highly comorbid with many other psychiatric conditions, including depression and anxiety.4,5 In particular, several studies have shown a strong comorbidity between ADHD and obsessive-compulsive disorder (OCD).6,7

Stimulant medication is usually the first-line ADHD treatment in both the adult and the pediatric populations. In adults, methylphenidate (MPH: Concerta, Daytrana, Focalin, Metadate CD, Methylin, Ritalin) is efficacious when administered in weight-adjusted doses equivalent to those used in children.8 MPH is available in short- and intermediate-acting preparations, as well as slow-release and long-acting ones. Immediate-release MPH reaches peak plasma concentration after two hours and decreases thereafter, necessitating administration several times a day.9 Long-acting formulations, such as once-daily osmotic release oral system (OROS) MPH, improve adherence and demonstrate efficacy similar to that of an immediate-release dose of MPH. The NHS National Institute for Health and Clinical Excellence (NICE) 2008 guidelines for treatment of adult ADHD set the maximum dose at 100mg of MPH/day.10 However, some patients do not achieve symptom remission at that dose.

Liebrenz et al. present a case report of a 38-year-old Caucasian man with comorbid symptoms of ADHD and OCD who remained symptomatic until the was treated with an extremely high dose of MPH (378mg/day).11 The patient was diagnosed with ADHD at age 9 and was treated with a variety of stimulants, including MPH and sustained-release MPH daily. At age 13, these agents were discontinued, and he was switched to desipramine, until, at age 18, symptoms of OCD developed, and clomipramine 75mg was added to his regimen, along with counseling. Symptoms of hyperactivity and inattention persisted, and the patient resumed taking MPH (60mg/day) at age 22, three years after entering college. He was unable to finish college, due to difficulties in focusing, and several attempts to obtain a secondary degree in the United States, Great Britain, and Switzerland also failed.

For unknown reasons, he did not receive further stimulant medication until age 32, when he started taking immediate-release MPH (60mg/day) to reduce distractibility at his newfound job as a sales clerk. Although it was somewhat effective, improvements were not sustained through the day, so during the following 14 months, he began to use MPH excessively, both orally and rectally, at doses of 4,800 to 6,000mg/day.

At age 34, he began treatment at the Outpatient Clinic for Patients with ADHD at the Psychiatric University Hospital in Zurich, Switzerland, where the authors are affiliated. He was diagnosed with an obsessive-compulsive disorder, as well as combined personality disorder and the diagnosis of ADHD was confirmed. Treatment was begun with fluoxetine (40mg/day) and immediate-release MPH 200mg, which was then increased to 240mg and finally 270mg/day.

Using a combined approach of CBT and pharmacologic management, his dose of MPH was initially reduced to 200mg/day; however, he continued to experience pronounced symptoms of ADHD, which affected his family relationships. While his signs of OCD diminished with fluoxetine, his ADHD symptoms only improved dramatically after he began treatment extended-release MPH (378mg/day). His Global Assessment of Functioning scale score increased from 43 to 68, and he began to care for his child several days a week and reestablish interpersonal relationships at home.

During treatment, he was carefully monitored for cardiac side effects (e.g., tachycardia and hypertension), as well as manic symptoms, suicidal ideation, and psychosis, all of which were absent. Symptoms such as agitation and irritability, which can be signs of MPH abuse, were likewise absent. Moreover, there was no return to the excessive use of MPH.

The authors conclude, "To our knowledge, this is the first reported case of high-dose treatment in a patient with adult ADHD. We therefore suggest that clinicians consider these findings in their work with patients when ADHD symptoms do not improve sufficiently with currently recommended dosages of stimulants." They advise close monitoring of clinical symptoms for potential adverse effects when using these higher dosages.

1. Faraone SV, Antshel KM. Diagnosing and treating attention-deficit/hyperactivity disorder in adults. World Psychiatry. 2007;7:131–136

2. Rosler M, Casas M, Konofal E, Buitalaar J. Attention deficit hyperactivity disorder in adults. World J Biol Psychiatry. 2010;11:684–698.

3. Kolar D, Keller A, Golfinopoulos M, et al. Treatment of adults with attention-deficit/hyperactivity disorder. Neuropsych Dis Treatment. 2008;4(2):389–403.

4. Kessler RC, Adler L, Barkley R, et al. The prevalence and correlates of adult ADHD in the United States: Results from the National Comorbidity Survey Replication. Am J Psychiatry. 2006;163:716–723.

5. Biederman J, Petty CR, Woodworth KKY, et al. Adult outcome of attention-deficit/hyperactivity disorder: A controlled 16-year follow-up study. J Clin Psychiatry. 2012;73(7):941–950.

6. Van Ameringen M, Mancini C, Simpson W, Patterson B. Adult attention deficit hyperactivity disorder in an anxiety disorders population. CNS Neurosci Ther. 2011;17(4):221–226.

7. Schatz DB, Rostain AL. ADHD with comorbid anxiety: A review of the current literature. J Atten Disord. 2006;10(2):141–149.

8. Faraone SV, Spencer T, Aleardi M, et al. Meta-analysis of the efficacy of methylphenidate for treating adult attention-deficit/hyperactivity disorder. J Clin Psychopharmacol. 2004;24:24–29.

9. Nair R, Moss SB. Management of attention-deficit hyperactivity disorder in adults: Focus on methylphenidate hydrochloride. Neupsychiatr Dis Treat. 2009;5:421–432.

10. Kendall T, Taylor E, Perez A, Taylor C. Diagnosis and management of attention-deficit/hyperactivity disorder in children, young people, and adults: Summary of the NICE guidance. BMJ Clinical research ed. 2008; 337:a1239.

11. Liebrenz M, Hof D, Buadze A, et al. High dose methylphenidate treatment in adult attention deficit hyperactivity disorder: A case report. J Med Case Rep. 2012;6(1):125.
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