Doctors prescribe hydrocodone APAP for the treatment of pain, according to MedicineNet. The drug is a combination of the narcotic hydrocodone and the non-narcotic pain-relieving analgesic acetaminophen. The indication of 5/325 on the prescription indicates that the medication contains 5 milligrams of hydrocodone and 325 milligrams of acetaminophen, notes RxList.
Hydrocodone blocks nerve cell receptors in the brain that create the sensation of pain, while acetaminophen elevates the pain threshold, reports MedicineNet. Frequently sold under the brand names Lortab and Vicodin, hydrocodone APAP relieves moderate to moderately severe pain. Common side effects of use include vomiting, nausea, sedation, dizziness and lightheadedness, among others.