Side effects of methylphenidate in childhood cancer survivors: a randomized placebo-controlled trial.
OBJECTIVE
To investigate the frequency and severity of side effects of methylphenidate among childhood survivors of acute lymphoblastic leukemia and brain tumors and identify predictors of higher adverse effect levels.


METHODS
Childhood cancer survivors (N = 103) identified as having attention and learning problems completed a randomized, double-blind, 3-week, home-crossover trial of placebo, low-dose methylphenidate (0.3 mg/kg; 10 mg twice daily maximum) and moderate-dose methylphenidate (0.6 mg/kg; 20 mg twice daily maximum). Caregivers completed the Barkley Side Effects Rating Scale (SERS) at baseline and each week during the medication trial. Siblings of cancer survivors (N = 49) were recruited as a healthy comparison group.


RESULTS
There was a significantly higher number and severity of symptoms endorsed on the SERS when patients were taking moderate dose compared with placebo or low dose, but not low dose compared with placebo. The number of side effects endorsed on the SERS was significantly lower during all 3 home-crossover weeks (placebo, low dose, moderate dose) when compared with baseline symptom scores. The severity of side effects was also significantly lower, compared with baseline screening, during placebo and low-dose weeks but not moderate-dose weeks. Both the number and severity of symptoms endorsed at baseline were significantly higher for patients compared with siblings. Female gender and lower IQ were associated with higher adverse effect levels.


CONCLUSIONS
Methylphenidate is generally well tolerated by childhood cancer survivors. There is a subgroup at increased risk for side effects that may need to be closely monitored or prescribed a lower medication dose. The seemingly paradoxical findings of increased "side effects" at baseline must be considered when monitoring side effects and designing clinical trials.
Conklin
Heather M
HM
Divisionsof Behavioral Medicine, St Jude Children's Research Hospital, Memphis, Tennessee 38105-2794, USA. heather.conklin@stjude.org
Lawford
Joanne
J
Jasper
Bruce W
BW
Morris
E Brannon
EB
Howard
Scott C
SC
Ogg
Susan W
SW
Wu
Shengjie
S
Xiong
Xiaoping
X
Khan
Raja B
RB
D000293:Adolescent; D001932:Brain Neoplasms / Q000453:epidemiology*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000009:adverse effects*; D002648:Child; D003072:Cognition Disorders / Q000188:drug therapy* / Q000453:epidemiology*; D015897:Comorbidity; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage / Q000009:adverse effects*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology*; D017741:Survivors
D000697:Central Nervous System Stimulants; D008774:Methylphenidate