Which of the following is classified as a stimulant?

Ritalin is classified as a stimulant because it contains methylphenidate, which is a central nervous system (CNS) stimulant. This medication is commonly prescribed to treat attention-deficit hyperactivity disorder (ADHD) and narcolepsy. Stimulants work by increasing the levels of certain neurotransmitters in the brain, primarily dopamine and norepinephrine, which help to improve focus and concentration in individuals with ADHD.

In contrast, Skelaxin is a muscle relaxant and does not have stimulant properties. Motrin, also known as ibuprofen, is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain and reduce inflammation, not a stimulant. Synthroid contains levothyroxine, a synthetic hormone used to treat hypothyroidism, which does not act as a stimulant in the way that Ritalin does. Each of these medications serves a different therapeutic purpose, making Ritalin unique in its classification as a stimulant.