Bupivacaine, marketed under the brand name Marcaine among others, is a medication used to decrease feeling in a specific area. It is used by injecting it into the area, around a nerve that supplies the area, or into the spinal canal's epidural space. It is available mixed with a small amount of epinephrine to make it last longer. It typically begins working within 15 minutes and lasts for 2 to 8 hours.Possible side effects include sleepiness, muscle twitching, ringing in the ears, changes in vision, low blood pressure, and an irregular heart rate. Concerns exist that injecting it into a joint can cause problems with the cartilage. Concentrated bupivacaine is not recommended for epidural freezing. Epidural freezing may also increase the length of labor. It is a local anaesthetic of the amide group.Bupivacaine was discovered in 1957. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Bupivacaine is available as a generic medication and is not very expensive. The wholesale cost in the developing world of a vial is about US$2.10.