Overview of Pain Medications

Pain medications are often the first course of treatment in pain management. Recently, there has been a rapid increase in the number and types of pain medications. There is a wide range of medicines available to treat the various types, intensities, and categories of pain.

Pain can be acute (e.g., sudden and intense pain from an injury or illness) or chronic (e.g., persistent pain that is long lasting, such as low back pain). Pain intensity can be described as mild, moderate, or severe.

Categories of pain include nociceptive pain, which is pain associated with an injury, such as a burn or a broken bone, and neuropathic pain, which usually occurs from changes in the nervous system, such as from shingles or RSD/CRPS. Pain of neuropathic origin often is described in terms of abnormal sensations (e.g., heat, burning, cold, numbness). Most pain medications are more effective when used to treat nociceptive pain than neuropathic pain.

For a number of reasons, pain, especially chronic pain, is often undertreated. Some types of pain medication (e.g., opioids drugs) have a high risk for causing dependency and physicians may be reluctant to prescribe these medications.

In some cases, patients do not provide accurate information about pain levels to their pain management team. When treating pain, good communication between the patient and health care providers is important. Friends or family members can also provide information about the patient's pain, especially if the patient is unable to do so.

Types of Pain Medications

An analgesic is a medicine that temporarily reduces or relieves pain. Analgesics can make short-term pain more tolerable, but do not eliminate the cause for the pain. There are two types of analgesics used to manage pain: non-opioid analgesics and opioid analgesics.

Adjuvant drugs also may be prescribed to treat patients who experience pain. Adjuvant drugs increase the efficacy or strength of other medications.

Non-opioid Analgesics

Some analgesics are available over-the-counter, meaning they do not require a prescription. Prescription non-opioid analgesics are also available, but whether they are more effective than over-the-counter drugs is questionable. Prescription varieties typically are more expensive than over-the-counter medications.

Non-opioid analgesics include acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs). There is an upper limit to the effectiveness of these medications, and increasing the dosage beyond a certain point does not increase pain relief. Non-opioid analgesics are not habit-forming. Studies have shown that 20–40% of patients achieve adequate pain relief with these medications.

Acetaminophen is available over-the-counter and by prescription. This medication relieves mild pain and reduces fever, but does not reduce inflammation (i.e., swelling and irritation).

Acetaminophen often is used to treat mild headache and arthritis pain, muscle pain, toothaches, back pain, and pain and discomfort caused by colds. Tylenol® is a commonly used brand of acetaminophen.

Acetaminophen is considered safer for long-term use than other non-opioid analgesics. It may be combined with other drugs (e.g., NSAIDs, opioid analgesics) to provide additional pain relief. Acetaminophen combinations include the following:

  • Acetaminophen with aspirin
  • Acetaminophen with aspirin and caffeine (e.g., Excedrin®)
  • Acetaminophen with codeine
  • Acetaminophen with hydrocone (e.g., Vicodin®)
  • Acetaminophen with oxycodone (e.g., Percocet®)

In August 2013, the FDA released a warning stating that acetaminophen can cause rare but serious skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis, acute generalized exanthematous pustulosis), which may be fatal. These reactions, which also may occur with NSAIDs, can result from first-time acetaminophen use or at any time when using the medication. If you are using an over-the-counter or prescription medication and develop a skin rash, stop taking the drug and seek immediate medical attention.

Excedrin® is used to treat headache and migraine pain, muscle pain, menstrual cramps, arthritis, back pain, toothaches, and pain and discomfort due to colds and sinus infections. Its relative strength is similar to a dose of ibuprofen. Taken together, alcohol, acetaminophen, and aspirin can damage the liver and stomach. Side effects include liver damage, nausea, vomiting, and abdominal pain.

Codeine is an opioid analgesic. Physicians may prescribe a combination of acetaminophen and codeine to treat moderately severe pain. Its relative strength is approximately double that of acetaminophen or an NSAID taken alone. Side effects include dizziness, shortness of breath, nausea, vomiting, and constipation.

Acetaminophen with hydrocone (e.g., Vicodin®) can be addictive when used long term. It is usually prescribed for less than one week. Possible side effects include nausea, vomiting, constipation, dizziness, drowsiness, and feeling disoriented.

Acetaminophen with oxycodone (e.g., Percocet®) is considered stronger than acetaminophen with hydrocone. Serious reactions can include respiratory depression, apnea, low blood pressure (hypotension), and shock. Common side effects include dizziness, drowsiness, nausea, vomiting, and constipation.

In some cases, the pain management team recommends taking an NSAID for short-term relief and then supplementing the drug using acetaminophen with hydrocone or acetaminophen with oxycodone, as needed.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 03 Jan 2000

Last Modified: 28 Jul 2014