For children with attention deficit / hyperactivity disorder, who take a weekend or summer break methylphenidate it may have some advantages. A medication “vacation” can help assess whether a medication is still useful and possibly help tolerate it, gain weight, and suppress growth. But drug vacations are not without its problems, said Lily Hechtman, MD, FRCP, a professor in the department of psychiatry at McGill University in Montreal, during a session at the World Congress on ADHD – Virtual event.
Stopping taking a drug can have health and social repercussions, warned Hechtman, presenter and moderator of the session, “The unsolved mysteries in the treatment of ADHD with psychostimulants.”
He rate of drug holidays ranges from 30% to 40% in patients with ADHD. Patients have multiple reasons to take them, Hechtman said. The American Academy of Child and Adolescent Psychology, as well as the National Institute for Health and Clinical Excellence, recommend this method for assessing whether a drug is still needed. Parents can opt for a drug vacation because most prefer their children to take fewer medications.
A drug vacation can counter some of the key side effects of stimulant medications such as decreased appetite and weight loss, and the mood swings and irritability that accompanies medication, as well as sleep problems.
It can also be used to prevent drug tolerance, the need to increase the dose as the 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. “Therefore, the longer the child is taking medication, the more likely he or she will have a certain tolerance to medication,” Hechtman said.
It is hypothesized that a vacation period with drugs causes the resensitization of neurons in the brain because they are not exposed to the stimulation of dopamine release and exposure to dopamine.
The minimum time a patient needs a vacation with medication to cope with a certain tolerance is approximately one month. “Even if you have a drug vacation and your drug tolerance has decreased, it can reappear with increasing doses once the medication is resumed” after the vacation, Hechtman said.
The growth factor
A drug holiday can also address concerns about suppressing growth. “Some studies show that drug holidays help suppress growth and others don’t,” Hechtman said.
Over a ten-year period, “it could be seen that the rate of drug use decreased significantly over time” among participants, said Hechtman, co-author of the MTA research. Only 10% of those who started the study between the ages of 7 and 9 continued to use stimulants 10 years later. By observing the short-term effects on the growth of these children, those who never started with stimulants had no growth suppression, while those who received early and consistent treatment experienced the greatest growth suppression.
Comparatively, incoherently medicated participants had lower growth suppression than those who were left with medications. “They were pretty close to the controls,” Hechtman said.
These patterns continued at 16-year follow-up as these patients became adults. Based on the results of the inconsistently treated group, this suggests that drug holidays may limit the effects of growth suppression, at least to some extent, Hechtman said.
Other studies have yielded several results on the impact of drug vacations on height and weight. “Evidence of the usefulness of drug vacations for the side effects of medication exists to decrease appetite and weight, but not so much to decrease height,” Hechtman summarized.
A recent one to study of 230 children of James Waxmonsky and colleagues who examined drug vacations on weekends and summers showed that drug vacations increased in weight but, curiously, not in height. Previous studies cited by Hechtman had inconsistent results on height and weight gain and loss. A 2012 study suggested that drug vacations resulted in a slight improvement in appetite for both the weekend and the school holidays. But only 9% of the children in the sample (n = 51) saw their appetite return to normal levels.
“Negative things can happen”
The downside of the drug vacation is that parents can rationalize that their child is okay without the medication and leave it. The process of stopping and starting medication can cause other problems. “Negative things can happen during drug holidays,” Hechtman said.
The large variability of doses over the weekend can cause bounces and side effects.
A child can go from a full dose, which can be 50 to 60 mg of stimulant to zero from Friday to Saturday. As a result, they have a lot of rebounding that Saturday. Similarly, they go from zero on Sunday to full dose on Monday, causing many side effects. “In addition, they will never have a stable effective dose due to the roller coaster effect of being in and out of drugs,” he noted.
Lack of consistency and adaptation to side effects can lead to medication discontinuation.
Outside of medication, the child may have more accidents or more injuries. “His behavior outside of medication can be such that it leads to social problems,” Hechtman continued. Weekend activities that require medication may be affected, such as homework or school projects, family or religious gatherings, or sports and social activities with family and peers. If the child behaves poorly outside of medication, he or she may be expelled from these activities. If it is a summer vacation with drugs, they can be kicked out of camp or by the pool.
If the child’s condition is already getting worse and there is also a holiday period with drugs, the child may experience a rebound or relapse, in which the condition seems much worse than with drugs.
Do holidays matter with drugs?
Another speaker at the session, James Swanson, Ph.D., who noted that “the onset of tolerance may limit and ultimately undermine the initial relative benefit” of stimulants, said there may be cases where vacations in the drug may be impractical.
Given the low adherence to ADHD medication, “most cases of treated ADHD stop taking medication anyway and these patients do not have the opportunity to take drugs,” he said in an interview.
“If tolerance arises, for a long-term treatment the concept of drug vacation seems hard to me to evaluate,” said Swanson, director of the University of California’s Child Development Center, Irvine.
Planned drug breaks may not be a good way to evaluate effectiveness unless performed under “double-blind” conditions, he offered. The MTA used an approach to switch between short periods of time, with and without medication. “We did this to compare drugs with placebo and compare drug doses to optimize short-term benefit,” said Swanson, co-author of the MTA study.
Hechtman receives funding from The Canadian Institutes of Health Research. Swanson has two patents: (PIXA4), which uses a “flight time” camera to measure infant growth and a provisional patent on the stimulant medication tolerance mechanism (PATSMTA).
This article originally appeared on MDedge.com, which is part of the Medscape professional network.