NEW YORK – Assessing nonresponsiveness to attention-deficit/hyperactivity disorder treatment requires a bit of detective work, according to Dr. Laurence L. Greenhill.

The reason can be as simple as a little kid not being able to swallow a big pill, or as complex as a dysfunctional family dynamic that interferes with medication adherence. But once the problem is rooted out and addressed, most refractory patients can experience a good response, Dr. Greenhill said at a psychopharmacology update held by the American Academy of Child and Adolescent Psychiatry.

Since primary care physicians usually continue to manage children who respond to ADHD medications, psychiatrists are usually the ones who see nonresponders, said Dr. Greenhill, a child and adolescent psychiatrist at the New York Psychiatric Institute.

Medication nonadherence, the most common cause of a failure to improve, can arise from numerous situations.

On the simple side, it might be a matter of finding the right form of medication; a liquid or sprinkle capsule might be much easier for a child to take than a pill. And not all pills are created equally easy to take.

"For example, [the osmotic controlled release oral delivery system methylphenidate] just went off patent, and generics are now available. But some of these generics are much bigger. In fact, one of the 18-mg pills is twice as large as the patent medicine, and lots of kids can’t swallow it," he said.

The ADHD medication guide published by Long Island Jewish Hospital can be a helpful tool when working with parents on this issue. It lists all the Food and Drug Administration–approved medications for ADHD, with full-size photographs of each capsule, tablet, or pill.

Some generics are not pharmacokinetically or pharmacodynamically identical to the original formulation, Dr. Greenhill noted. Although the drug has to be molecularly identical and dose identical, "the ascending dose curve and duration of action need not be matched." Some generic formulations do fall into this problematic category. "For this reason, I try to encourage parents to get the brand," said Dr. Greenhill, adding that he has no financial interest in any of the drugs.

Medication nonadherence also can be attributable to uncomfortable or even intolerable side effects. These can include gastrointestinal issues, trouble sleeping, lack of appetite, restlessness, irritability, and "feeling fidgety."

Dosage adjustments or a medication change might be in order. For appetite issues, recommend giving the medication after meals, and reassure parents it’s OK to let a child eat later in the evening, when hunger may return.

It’s important to get the child’s growth records from the pediatrician, and plot height and weight curves every 6 months. If there’s a consistent fall-off, consider lowering the dose or changing to another drug.

Contrary to widely held belief, stimulants don’t pose significant cardiac risks to most children. A baseline electrocardiogram is really only necessary for a child who has a family history of sudden cardiac death or a personal history of syncope or cardiac abnormalities. Blood pressure and pulse should be monitored at every visit.

Melatonin is worth a try for youngsters whose ADHD meds interfere with good sleep, Dr. Greenhill said.

"I would start at 1 mg/night and work up," he said. "Starting at a high dose can actually shut off the naturally occurring melatonin. Plasma levels peak about an hour after taking it, so timing is important. I usually start with it about 3 hours before the scheduled sleeping time and then adjust."

Family dynamics also can play a big role in medication nonadherence. "ADHD families are often poor at scheduling activities, sometimes to the extent that parents are the ones who forget to give the medication. They also might not have a clear idea of how to give it, and just leave it on the kitchen table, making it the child’s responsibility to take it every day.

"If this is a child who can’t remember to bring homework back from school, then how is he going to remember to stay on schedule with medication?"

If it’s clear that parents are having difficulty in this area, the simplest thing to do is send the medicine to school and ask the nurse to administer it. Switching to a long-acting form might help, too, since it’s just easier to remember to take one pill than to take two.

The ADHD Parents Medication Guide is a great resource that can be used to get parents actively involved with the child’s drug therapy, Dr. Greenhill said. Developed by the American Psychiatric Association and the American Academy of Child and Adolescent Psychiatry, the online guide is designed to help families and physicians work together to make the best decisions about a child’s care.

Dr. Greenhill is on the advisory board of Quotient, which manufactures an ADHD testing system, and is a consultant for the Health Information Technology Lab.

msullivan@frontlinemedcom.com

When ADHD doesn’t improve, check medication adherence first