Narcotics, more precisely called opioids in modern medicine, are primarily used to treat moderate to severe pain. They work by binding to opioid receptors in the brain and spinal cord, reducing the intensity of pain signals and altering the emotional response to pain. Beyond pain relief, narcotics serve several other medical purposes, including surgical anesthesia, cough suppression, and even diarrhea treatment.
Pain Relief for Acute and Severe Pain
The most common medical use of narcotics is managing pain that’s too intense for over-the-counter medications to handle. This includes pain after surgery, serious injuries, burns, kidney stones, and cancer. In hospitals, opioids like morphine, hydromorphone, and fentanyl are frequently given intravenously around the time of surgery to control pain while patients recover.
For outpatient situations, prescriptions typically start at the lowest effective dose. The CDC’s 2022 prescribing guideline recommends that doctors start opioid-naïve patients at roughly 20 to 30 morphine milligram equivalents per day. A common example: one tablet of hydrocodone 5 mg combined with acetaminophen, taken no more than every four hours as needed. The emphasis is on “as needed” rather than on a fixed schedule, and for many types of nonsurgical pain, a few days or less is often enough.
Morphine can also be delivered directly into the spinal area through implantable pumps, a technique reserved for chronic pain and palliative care when other routes aren’t sufficient.
Chronic Non-Cancer Pain
Using narcotics for long-term pain that isn’t related to cancer is more controversial. The CDC guideline states that doctors should consider opioid therapy for chronic pain only when the expected benefits for both pain and daily function outweigh the risks. The evidence for long-term benefit is mixed.
A large Cochrane review found that among patients who stayed on oral opioids for six months, about 44% achieved at least a 50% reduction in pain. That’s meaningful for the people it helps, but many patients drop out before reaching that point because of side effects or inadequate relief. Whether long-term opioid use improves quality of life or the ability to function day-to-day remains unclear from the available evidence. Signs of addiction appeared in only about 0.27% of participants in the studies that tracked it, though the real-world rate depends heavily on individual risk factors and how prescriptions are managed.
Surgical Anesthesia
During surgery, narcotics play a critical role as part of general anesthesia. Fentanyl and its faster-acting derivative remifentanil are commonly used to provide pain control while a patient is under anesthesia. Remifentanil is especially useful because the body clears it rapidly, regardless of how long the surgery takes. In studies of elderly patients undergoing spinal surgery, those who received remifentanil woke up faster, started breathing on their own sooner, and were extubated more quickly compared to those given fentanyl. This faster recovery can reduce the risk of postoperative complications like respiratory depression.
Remifentanil is also preferred for patients with kidney or liver problems and those with obesity, because its breakdown doesn’t depend on those organs functioning normally.
Cough Suppression
Some narcotics act directly on the cough center in the brainstem, making them effective cough suppressants. Codeine was historically the most widely known opioid used for this purpose, but hydrocodone is also approved as an antitussive for adults and children six and older. These medications quiet a persistent, nonproductive cough that disrupts sleep or daily life. Because they carry the same risks as other opioids, including dependence and respiratory depression, they’re generally reserved for coughs that don’t respond to non-narcotic treatments.
Diarrhea Treatment
One of the lesser-known uses of narcotics is controlling diarrhea. Diphenoxylate, an opioid that acts on receptors in the gut’s own nervous system, slows down intestinal contractions and extends the time it takes food to move through the digestive tract. This reduces the urgency and frequency of bowel movements. It’s combined with a small amount of atropine (to discourage misuse) and prescribed for acute and chronic diarrhea in adults and teens 13 and older.
This medication is only appropriate for non-infectious diarrhea. When diarrhea is caused by a bacterial infection, slowing the gut down can trap bacteria and their toxins inside, potentially leading to serious complications including sepsis.
Common Side Effects
All narcotics share a core set of side effects because they act on the same type of receptors throughout the body. The most frequent include sedation, nausea, vomiting, and constipation. Constipation is particularly persistent and doesn’t tend to improve over time the way other side effects do.
The most dangerous side effect is respiratory depression, where breathing slows to fewer than 8 to 10 breaths per minute. This is dose-dependent, meaning higher doses carry a greater risk, and it’s the primary cause of death in opioid overdoses. In a study of hospitalized patients, 16% of those who experienced adverse opioid events had documented breathing rates of 8 or fewer per minute combined with significant drowsiness. Risk increases when opioids are combined with other sedating substances like alcohol or benzodiazepines.
How Narcotics Are Regulated
Under the Controlled Substances Act, narcotics are placed into one of five schedules based on their medical usefulness, potential for abuse, and likelihood of causing dependence. The DEA evaluates eight specific factors when scheduling a drug, including its pattern of abuse, risk to public health, and whether it causes physical or psychological dependence. Heroin, for instance, sits in Schedule I with no accepted medical use, while morphine, fentanyl, and oxycodone are Schedule II, meaning they have legitimate medical applications but carry a high potential for abuse. Codeine-containing cough preparations with lower concentrations fall into Schedule III or V, reflecting their comparatively lower abuse potential.
If you’re prescribed an opioid for pain, current guidelines favor the shortest effective course. For continuous use lasting more than a few days, a gradual taper is recommended to avoid withdrawal symptoms. For courses under a week, cutting the dose in half for two days before stopping is a common approach. For use lasting one week to a month, a slower taper of about 20% reduction every two days is typical.