The big question is if opioids are even appropriate for chronic non-cancer pain at all. Second question is if you feel they are (basically what Ducttape said), is it worth the hassle. There is a lot of red tape to push through for opioid therapy, people rarely get better, and nobody thanks you, especially the government.
That being said, there are multiple layers of regulations/guidelines. Most important are the CDC, DEA, and your state government. In general:
1. DEA states chronic C2 patients should be seen "frequently reassessed" and "at least every 3 months", but you can only write for a 30 day supply at a time. It IS legal to write two more 30 days supplies with a "Do not fill" date on it to get to 3 months, but the general understanding is see patient's every month for reeval and refill if appropriate.
2. You need to evaluate patient's risk of overdose (low, medium, high) with at least one validated opiate risk tool (ORT). You should also evaluate risk by their medical/psychological/social history.
3. Urine drug screen frequency should be based on risk score. In general, 1-2/year for low risk, 3-4/year for moderate risk, and 4-6/year for high risk. You can also do a UDS as needed. This should be random, not on a schedule.
4. You should check your state's PDMP (Prescription Drug Monitoring Program) before every prescription.
5. You need to establish an opiate contract with the patient detailing the do/don'ts and they need to sign this agreement.
6. You should also do random pill counts intermittently. Meaning you call the patient and they have 24 hours to come in with their meds and show you they have the amount of pills they should have. No more, no less.
7. In general, people should be below 50 MMED (Milligrams of Morphine Equivalents per day), or at least below 90MMED. Risk of overdose increases dramatically at these two points and many regulations are based on them.
8. You should give Narcan to everyone on opiates, but especially anyone who is Moderate or High risk.
9. You should avoid opiates on anyone concurrently on Benzodiazepines or Soma and be cautious with anyone on other sedatives.