For children with attention-deficit/hyperactivity disorder, taking a weekend or summer break from methylphenidate may have some benefits. A drug “holiday” can help assess whether a drug is still useful and possibly help with drug tolerance, weight gain, and growth suppression. But drug holidays are not without their problems, Lily Hechtman, MD, FRCP, professor at the department of psychiatry, McGill University, Montreal, said during a session at the World Congress on ADHD – Virtual Event.
Dr. Lily Hechtman
Ceasing a medication can have repercussions from a health and social standpoint, cautioned Dr. Hechtman, a presenter and moderator of the session, “Unsolved mysteries in the treatment of ADHD with psychostimulants.”
The rate of drug holidays is somewhere between 30% and 40% in ADHD patients. Patients have multiple reasons for taking them, said Dr. Hechtman. The American Academy of Child & Adolescent Psychology as well as the National Institute for Health and Clinical Excellence recommend this method to assess whether a medication is still necessary. Parents may opt for a drug holiday because most would prefer their children to take less medication.
A drug holiday can counteract some of the key side effects of stimulant medication such as decreased appetite and weight loss, and the moodiness and irritability that accompanies the medication, as well as sleep problems.
It may also be used to avoid drug tolerance, the need to increase dosage as medication continues. A 2002 study of 166 children and adolescents treated with methylphenidate revealed that 60% had developed drug tolerance. Drug tolerance increases with duration. “So, the longer the child is on medication, the more likely he or she will develop some drug tolerance,” said Dr. Hechtman.
It is hypothesized that a drug holiday results in the resensitization of the neurons in the brain because they aren’t exposed to the stimulation of dopamine release and dopamine exposure.
The minimum time a patient needs a drug holiday to deal with some drug tolerance is about a month. “Even if you have a drug holiday and your drug tolerance has been decreased, it can reoccur with increasing dosages, once medication resumes” after the holiday, said Dr. Hechtman.
The growth factor
A drug holiday can also address concerns about growth suppression. “Some studies show that drug holidays help with growth suppression and others do not,” said Dr. Hechtman.
The Multimodal Treatment of ADHD (MTA) study, which followed children with ADHD from childhood to adolescence into adulthood, offers some key insights on the effects of treatment on growth.
Over a 10-year period, “you could see that the rate of medication use decreased significantly with time” among participants, said Dr. Hechtman, a coauthor of the MTA research. Only 10% who began the study aged 7-9 years were still using stimulants 10 years later. Looking at short-term effects on growth among these children, those who never went on stimulants to begin with had no growth suppression at all, whereas those who underwent early and consistent treatment experienced the greatest growth suppression.
Comparatively, inconsistently medicated participants had less growth suppression than those who remained on medication. “They were pretty close to the controls,” said Dr. Hechtman.
These patterns continued in a 16-year follow-up, as these patients became adults. Based on the results in the inconsistently treated group, this suggests that drug holidays can limit the effects of growth suppression, at least to a certain extent, said Dr. Hechtman.
Other studies have yielded varying results on the impact of drug holidays on height and weight. “The evidence for the utility of drug holidays for medication side effects is there for decreased appetite and weight, but not so much for decreased height,” summarized Dr. Hechtman.
One recent study of 230 children by James Waxmonsky and colleagues that examined drug holidays on weekends and summers showed that drug holidays did increase weight but interestingly, not height. Older studies Dr. Hechtman cited had inconsistent results on height and weight gain and loss. A 2012 study suggested that drug holidays resulted in a slight improvement in appetite for both weekend and school holidays. But only 9% of the children in the sample (n = 51) saw their appetite return to normal levels.