• Amphetamine: Antisleep drugs which are taken by truck drivers to keep them awake. Amphetamines are stimulants and thus reduce sleep, increase alertness.
Excessive dosage of cocaine causes hallucinations.
Cannabinoids (e.g., marijuana, hashish) are sometimes abused by sportspersons for euphoria or performance-related psychological effects.

• Morphine is an opioid depressant; it reduces pain, induces sleep/drowsiness, and depresses the central nervous system. It does not increase alertness. Morphine can be used as an analgesic which is usually given to the patients who have undergone surgery.