There are risks that anyone taking painkillers should consider. If your aunt has any history of substance abuse, or emotional problems, she is at risk for becoming addicted. The doctor prescribing drugs should know the patient's history, but with the high turnover at Indian Health Service clinics, this is not always the case.
Most people do not react well to painkillers; they feel nauseous, dizzy, and/or disoriented. Some people, though, experience a high and have a positive reaction. If your aunt falls into the second group, this is another risk factor for addiction.
Once the body starts taking painkillers, the brain’s natural endorphins (the hormones that make you happy) are no longer being produced, since the body is ingesting opiates, one of the ingredients in painkillers. Your aunt is not lying; her pain probably feels just as strong, if not stronger, than when she was first released from the hospital. The scary thing is that the pain from the actual surgery is probably almost gone. Once the patient stops taking painkiller and the opiates are no longer in the body, the body experiences a painful withdrawal syndrome, which is why your aunt is still experiencing pain. If she keeps taking this medication, it would not be to treat the pain from her surgery; it would be to treat her withdrawal symptoms. This causes an endless cycle of medication because her body has become dependent on this drug, especially if higher doses are used, which will lead to an addiction.
Substance Abuse: How to Help