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Analgesics Class of Medications (Painkillers & NSAIDs)

Whether you call them painkillers, pain relievers or pain medicines, analgesics are all about stopping or lowering pain and discomfort. But it’s important to use them wisely and as directed. Look at the label or talk to your healthcare provider if you have questions.

Overview

What are analgesics?

Analgesics are medicines that relieve pain. They’re also known as painkillers or pain relievers. They’re some of the most commonly used medicines worldwide.

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While they have a similar purpose, analgesics are different from anesthetics. Anesthetics block all sensations, including pain.

Types of analgesics

There are a few main types of analgesics. They are:

Several medications that aren’t analgesics still have pain-relieving properties. They commonly treat pain. They can do that as either standalone medicines or as part of combination treatments.

Acetaminophen

Acetaminophen comes under brand names like Panadol® or Tylenol®. It’s also known as paracetamol in some parts of the world. Acetaminophen is one of the most commonly used pain relievers worldwide. And it’s also good at reducing fevers. But one thing it can’t do is lower inflammation.

You can buy acetaminophen over the counter (OTC). Many OTC products for common illnesses combine acetaminophen with other medicines. Many prescription medicines also use it as a supporting ingredient.

NSAIDs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are analgesics that work by lowering inflammation. They’re also good for bringing a fever down and reducing swelling. Some examples of NSAIDs include:

  • Aspirin
  • Celecoxib (Celebrex®)
  • Ibuprofen (Advil®, Motrin®)
  • Indomethacin (Indocin®, Tivorbex®)
  • Ketorolac (Toradol®)
  • Meloxicam (Mobic™)
  • Naproxen (Aleve®, Naprosyn®)

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Opioids

Opioids are common, effective painkillers. But healthcare providers use them cautiously because of the possible side effects. And if you use them too long or other than prescribed, you can develop opioid use disorder.

Some examples of common opioid medications include:

  • Codeine
  • Fentanyl (Abstral®, Actiq®, Duragesic®, Fentora®)
  • Hydrocodone (Hysingla®) or combination medicines (Apadaz®, Co-Gesic®, Lorcet®, Norco®, Reprexain®, Vicodin®, Zydone®)
  • Hydromorphone (Dilaudid®)
  • Meperidine (Demerol®)
  • Methadone (Dolophine®, Methadose®)
  • Morphine (Duramorph®, Infumorph®, Kadian®, Mitigo®, MorphaBond ER®, MS Contin®)
  • Oxycodone (RoxyBond, Oxaydo®, Oxycontin®, Roxicodone®, Xtampza®) or combination medicines (Percocet®, Percodan®)
  • Oxymorphone (Opana®)

How do analgesics work?

Analgesics work in a few main ways:

  • Inflammation blocking
  • Opioid receptor activation
  • Lowering electrical activity
  • Pain modulation

Inflammation blocking

Your body uses hormone-like chemicals called prostaglandins as part of its defense system. Some prostaglandins are there to cause inflammation, which activates nerve endings that feel pain.

Your body makes prostaglandins using two types of cyclooxygenase (COX) enzymes. Without those enzymes, your body can’t activate inflammation and pain processes. That’s why many pain medicines, like acetaminophen and NSAIDs, are COX inhibitors.

Some COX inhibitors only work in certain places. For example, acetaminophen only affects COX enzymes in your brain. That may be why it doesn’t help inflammation. And some COX inhibitors are selective. That means they don’t affect both types. The COX-2 inhibitor celecoxib is an example of that.

Opioid receptor activation

Opioid medications lower pain-signaling activity in your nervous system. Your body has its own pain control system. That’s so you can still react to try to protect yourself from whatever’s causing pain. Opioids use the same receptors that your body’s own pain control system uses. That lets them make certain parts of your nervous system send out pain-blocking impulses.

Lowering electrical activity

Some medications take advantage of how your cells use electrolytes, like sodium, calcium or potassium. They limit how these electrolytes get into your cells. And when those cells are part of how you feel pain, your pain level goes down. Gabapentin and pregabalin are examples of that.

Pain modulation

Some medications change the way your body handles pain signals. One way they do that is by changing levels of neurotransmitters like serotonin. That’s how other medication types, like tricyclic antidepressants and antiseizure drugs, can also help with pain.

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Who prescribes analgesic pain medication?

Many pain medicines are available without a prescription. You can buy them at pharmacies, grocery stores and even online.

But it’s also common for you to need a prescription for pain medicines. In the U.S., you always need a prescription for opioids and many other medicines that treat pain.

How should you take analgesics?

You should take analgesics as directed on the label or as prescribed by your healthcare provider. Most pain medicines come in one of the following forms:

  • Capsules or tablets you take by mouth
  • Dissolvable films you put in your mouth
  • Liquid you take by mouth
  • Nasal spray
  • Patches you wear on your skin
  • Solutions you receive through an injection or an intravenous (IV) line
  • Suppositories you take by putting them in your butthole (anus)
  • Topical creams, lotions or gels

What are the risks of using pain relievers?

The risks of using pain relievers vary depending on which medicines you’re taking. Some possible risks include:

  • Allergic reactions
  • Bleeding too much because your blood isn’t clotting well
  • Diarrhea or constipation
  • Kidney damage from taking too much of one or more NSAIDs
  • Liver damage from taking too much acetaminophen or drinking alcohol while taking it
  • Nausea, upset stomach or heartburn
  • Opioid overdose or opioid use disorder
  • Stomach ulcers

Does pain medication stop working after a while?

Sometimes, you can build up a tolerance to pain medicines. This is true for opioids and for many other types of pain medicines. And sometimes, using a pain medication too often can make pain worse, like with rebound headaches.

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When should I get medical attention for painkiller side effects?

You should get medical attention right away if you experience:

Additional Common Questions

What’s the best analgesic?

The best analgesic for you can depend on several factors. Healthcare providers use what’s called a “pain ladder” approach when deciding what analgesic to recommend. That means they usually start low with weaker pain medicines. If those don’t work, they move up the ladder to stronger options.

A note from Cleveland Clinic

Whether you have a mild headache or you’re recovering after a major surgery, analgesics are a key way to treat pain. But pain comes in different types and severities. That’s why there are multiple types of pain medicines and even more ways to use them.

If you have questions about your pain and how to manage it, talk to your healthcare provider. Talk to them not just about how much or where it hurts, but how it affects your life. Explaining in detail can help your provider find the best approach to treating your pain.

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Care at Cleveland Clinic

Comprehensive pain recovery treatment plans can help you manage your pain levels and symptoms more easily.

Medically Reviewed

Last reviewed on 12/12/2025.

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