Great questions. There are a few issues here, and I will attempt to address all.
Over-the-counter (OTC) vs. Prescription (Rx-only)
- The Food and Drug Administration (FDA) oversees the regulatory approval of drugs, whether OTC or Rx-only.
- Most new drugs go through a New Drug Application (NDA). The drugs are usually then classified as Rx-only.
- However, two mechanisms exist to make a drug OTC.
- The manufacturer can submit another NDA demonstrating the drug is appropriate for OTC categorization.
- One may submit a "drug monograph" and demonstrate the drug is generally accepted as safe and effective (GRASE).
- Most applications follow the first path (e.g., omeprazole, esomeprazole).
- The biggest difference is the NDA allows patent exclusivity giving the drug manufacturer a legal monopoly on sales.
Safety of pain medications
- Pain medications are a diverse grouping of drugs. Many pain medications exist from different classes of drugs; the different classes act on different parts of the body to reduce pain, and thus are not necessarily comparable.
- Non-steroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen (Advil), naproxen (Aleve), meloxicam (Mobic), etc.) are generally the first-line treatment for pain, especially pain related to arthritis and back pain.
- NSAIDs may increase the risk of bleeding (especially in the upper digestive tract), high blood pressure, kidney problems, and heart issues.
- Acetaminophen (APAP; Tylenol) is good choice for general pains and also for fevers. It is not as good for back pain as NSAIDs.
- Depending on the source of information, the maximum daily dose is somewhere around 3,000-4,000 mg per day. Higher doses may cause liver damage. Otherwise, acetaminophen is safe and effective.
- Opioids (e.g., morphine, methadone, oxycodone, etc.) are generally reserved for severe, acute pain or chronic cancer-related pain. We've tended to overuse opioids for chronic, non-cancer pain in the past 20 years, which was a major cause of the current opioid epidemic.
- Opioids increase the risk of severe respiratory depression (decreased drive to breathe), overdose, and death.
- In the past 20 years, over 400,000 people have died from opioid overdoses, about the same number of Americans who died in World War II.
In summary, the OTC vs Rx issue is largely related to regulations based on the safety and effectiveness of a medication. "Pain medications" is a broad category, and each drug carries its own risks. Opioids possess a high risk for adverse outcomes, and low efficacy.
Also keep in mind, there are topical medications to treat pain, and there are even non-medication alternatives for treatment of pain, such as physical therapy, cognitive behavioral therapy for chronic pain, yoga, tai chi, acupuncture, chiropractic, TENS units, and more.