Final answer:
Parents should be instructed to contact the healthcare provider if their child experiences a change in voiding pattern while taking Strattera for ADHD, as this can be a side effect of the medication.
Step-by-step explanation:
A 13-year-old child is receiving Strattera as treatment for ADHD. When creating a teaching plan for the parents, a nurse would instruct the parents to contact the healthcare provider if they notice a change in voiding pattern. Strattera (atomoxetine) can cause urinary retention and other urinary side effects, which would necessitate medical attention. Increased attentiveness and improvement in behavior are expected outcomes of the medication, while a lack of social interaction can be a symptom of ADHD itself but is not specifically related to the medication side effects.