Conference Coverage

What to do when stimulants fail for ADHD


 

EXPERT ANALYSIS FROM AAP 2019

NEW ORLEANS – A variety of reasons can contribute to the failure of stimulants to treat ADHD in children, such as comorbidities, missed diagnoses, inadequate medication dosage, side effects, major life changes, and other factors in the home or school environments, said Alison Schonwald, MD, of Harvard Medical School, Boston.

Mother and child with a pediatrician gpointstudio/Thinkstock

Stimulant medications indicated for ADHD usually work in 70%-75% of school-age children, but that leaves one in four children whose condition can be more challenging to treat, she said.

“Look around you,” Dr. Schonwald told a packed room at the annual meeting of the American Academy of Pediatrics. “You’re not the only one struggling with this topic.” She sprinkled her presentation with case studies of patients with ADHD for whom stimulants weren’t working, examples that the audience clearly found familiar.

The three steps you already know to do with treatment-resistant children sound simple: assess the child for factors linked to their poor response; develop a new treatment plan; and use Food and Drug Administration-approved nonstimulant medications, including off-label options, in a new plan.

But in the office, the process can be anything but simple when you must consider school and family environments, comorbidities, and other factors potentially complicating the child’s ability to function well.

Comorbidities

To start, Dr. Schonwald provided a chart of common coexisting problems in children with ADHD that included the recommended assessment and intervention:

Doctors also may need to consider other common comorbidities in children with ADHD, such as bipolar disorder, depression, learning disabilities, oppositional defiant disorder, and tic disorders.

Tic disorders typically have an onset around 7 years old and peak in midadolescence, declining in late teen years. An estimated 35%-90% of children with Tourette syndrome have ADHD, Dr. Schonwald said (Dev Med Child Neurol. 2006 Jul;48[7]:616-21).

Managing treatment with stimulants

A common dosage amount for stimulants is 2.5-5 mg, but that dose may be too low for children, Dr. Schonwald said. She recommended increasing it until an effect is seen and stopping at the effective dose level the child can tolerate. The maximum recommended by the FDA is 60 mg/day for short-acting stimulants and 72 mg/day for extended-release ones, but some research has shown dosage can go even higher without causing toxic effects (J Child Adolesc Psychopharmacol. 2010 Feb;20[1]:49-54).

Dr. Schonwald also suggested trying both methylphenidate and amphetamine medication, while recognizing the latter tends to have more stimulant-related side effects.

Adherence is another consideration because multiple studies show high rates of noncompliance or discontinuation, such as up to 19% discontinuation for long-acting and 38% for short-acting stimulants (J Clin Psychiatry. 2015 Nov;76(11):e1459-68; Postgrad Med. 2012 May;124(3):139-48). A study of a school cohort in Philadelphia found only about one in five children were adherent (J Am Acad Child Adolesc Psychiatry. 2011 May;50[5]:480-9).

One potential solution to adherence challenges are pill reminder smartphone apps, such as Medisafe Medication Management, Pill Reminder-All in One, MyTherapy: Medication Reminder, and CareZone.

Dr. Schonwald noted several factors that can influence children’s response to stimulants. Among children with comorbid intellectual disability, for example, the response rate is lower than the average 75% of children without the disability, hovering around 40%-50% (Res Dev Disabil. 2018 Dec;83:217-32). Those who get more sleep tend to have improved attention, compared with children with less sleep (Atten Defic Hyperact Disord. 2017 Mar;9[1]:31-38).

She also offered strategies to manage problematic adverse effects from stimulants. Those experiencing weight loss can take their stimulant after breakfast, drink whole milk, and consider taking drug holidays.

To reduce stomachaches, children should take their medication with food, and you should look at whether the child is taking the lowest effective dose they can and whether anxiety may be involved. Similarly, children with headaches should take stimulants with food, and you should look at the dosage and ask whether the patient is getting adequate sleep.

Strategies to address difficulty falling asleep can include taking the stimulant earlier in the day or switching to a shorter-acting form, dexmethylphenidate, or another stimulant. If they’re having trouble staying asleep, inquire about sleep hygiene, and look for associations with other factors that might explain why the child is experiencing new problems with staying asleep. If these strategies are unsuccessful, you can consider prescribing melatonin or clonidine.

Alternatives to stimulants

Several medications besides stimulants are available to prescribe to children with ADHD if they aren’t responding adequately to stimulants, Dr. Schonwald said.

Atomoxetine performed better than placebo in treatment studies, with similar weight loss effects, albeit the lowest mean effect size in clinician ratings (Lancet Psychiatry. 2018 Sep;5[9]:727-38). Dr. Schonwald recommended starting atomoxetine in children under 40 kg at 0.5 mg/kg for 4 days, then increasing to 1.2 mg/kg/day. For children over 40 kg, the dose can start at 40 mg. Maximum dose can range from 1.4 to 1.8 mg/kg or 100 mg/day.

About 7% of white children and 2% of African American children are poor metabolizers of atomoxetine, and the drug has interactions with dextromethorphan, fluoxetine, and paroxetine, she noted. Side effects can include abdominal pain, dry mouth, fatigue, mood swings, nausea, and vomiting.

Two alpha-adrenergics that you can consider are clonidine and guanfacine. Clonidine, a hypotensive drug given at a dose of 0.05-0.2 mg up to three times a day, is helpful for hyperactivity and impulsivity rather than attention difficulties. Side effects can include depression, headache, rebound hypertension, and sedation, and it’s only FDA approved for ages 12 years and older.

An extended release version of clonidine (Kapvay) is approved for monotherapy or adjunctive therapy for ADHD; it led to improvements in ADHD–Rating Scale-IV scores as soon as the second week in an 8-week randomized controlled trial. Mild to moderate somnolence was the most common adverse event, and changes on electrocardiograms were minor (J Am Acad Child Adolesc Psychiatry. 2011 Feb;50[2]:171-9).

Guanfacine, also a hypotensive drug, given at a dose of 0.5-2 mg up to three times a day, has fewer data about its use for ADHD but appears to treat attention problems more effectively than hyperactivity. Also approved only for ages 12 years and older, guanfacine is less sedating, and its side effects can include agitation, headache , and insomnia. An extended-release version of guanfacine (brand name Intuniv) showed statistically significant reductions in ADHD Rating Scale-IV scores in a 9-week, double-blind, randomized, controlled trial. Side effects including fatigue, sedation, and somnolence occurred in the first 2 weeks but generally resolved, and participants returned to baseline during dose maintenance and tapering (J Am Acad Child Adolesc Psychiatry. 2009 Feb;48[2]:155-65).

Intuniv doses should start at 1 mg/day and increase no more than 1 mg/week, Dr. Schonwald said, until reaching a maintenance dose of 1-4 mg once daily, depending on the patient’s clinical response and tolerability. Children also must be able to swallow the pill whole.

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