It became so only after mankind learned to increase the efficiency and effects of these substances. ... Prescription drugs such as tranquilizers , amphetamines , benzodiazepines , barbiturates , steroids , and analgesics can be knowingly or unknowingly over prescribed or otherwise used improperly. ... morphine Section: Effects and Uses Related: Pharmaceuticals Morphine, a narcotic , acts directly on the central nervous system. ... cocaine Section: Effects and Add...

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• Approx Pages: 20
• Grade Level: Undergraduate