which then slowly release the drug into the bloodstream over 48 to 72 hours, allowing for long-lasting relief from pain. The patches are available in generic form and are available for lower costs. Fentanyl patches are manufactured in five patch sizes: 12.5 micrograms /hour, 25 µg/h, 50 µg/h, 75 µg/h, and 100 µg/h. Dosage is