Is a amphetamine and antihistamine the same thing?

No, amphetamines and antihistamines are not the same thing. Amphetamines are stimulant medications commonly used to treat conditions like ADHD and narcolepsy by increasing the levels of certain neurotransmitters in the brain. In contrast, antihistamines are medications that block histamine receptors to relieve allergy symptoms and are often used to treat conditions like hay fever and motion sickness. Their mechanisms of action, uses, and effects on the body are quite different.