Editorial use only . Lenoltec - Ratio Lenoltec #3: acetaminophen (300 mg), caffeine (15 mg), codeine (30 mg). Combination medicines containing narcotic analgesics and acetaminophen are used to relieve pain. A narcotic analgesic and acetaminophen used together may provide better pain relief than either medicine used alone. In some cases, relief of pain may come at lower doses of each medicine. Narcotic analgesics act in the central nervous system (CNS) to relieve pain. In the U.S. these medicines are available only with a medical doctor's or dentist's prescription. In Canada, some acetaminophen, codeine, and caffeine combinations are available without a prescription.