Which of the following is a side effect of methylphenidate?

• A. Dry mouth, diarrhea, constipation, restlessness, tremors, irritability, tachycardia, palpitations, anorexia
• B. Hypotension and bradycardia
• C. Increased appetite and sleepiness
• D. Hair loss and rash

Answer: (A)

Methylphenidate is a central nervous system stimulant, and its common adverse effects reflect sympathetic and appetite-suppressing actions. It increases dopamine and norepinephrine in the brain by blocking their reuptake, which boosts alertness and focus but often comes with peripheral stimulation. Those effects include dry mouth, GI upset (diarrhea or constipation), restlessness, tremor, irritability, tachycardia, palpitations, and reduced appetite leading to anorexia. The combination listed matches these stimulant-side effects precisely.

The other options describe effects that are unlikely with methylphenidate: hypotension and bradycardia suggest opposite autonomic effects; increased appetite and sleepiness clash with the drug’s stimulatory profile; hair loss and rash are not typical primary adverse effects of this medication.