How do Pain Relieving Medicines work?

How do Pain Relieving Medicines work?

If you experience chronic pain from back problems, arthritis, joint injuries, or trauma then you know how it hampers your daily life.

Moreover, in areas that ache and throb constantly, chronic pain also causes other conditions such as sleep disturbances and anxiety.

Chronic pain not only makes you irritable but at same time affects your personal and work life.

When it comes to most common way to treat pain at home, a painkiller is first thing that you might consider.

Be it toothache or arthritis pain, painkillers or pain relievers are considered effective solutions.

It is important to know that all pain medications work in a different ways and provide relief from pain.

Depending upon type of pain and various other factors, your doctor determines which pain medicine is best for you.

What are pain relievers or pain medicines?

Pain medicines also called analgesics are considered as a cornerstone of modern medicine.

They provide quick relief from discomfort that is caused by different conditions.

Right from minor aches to chronic pain, these medications play an important role in improving quality of life for individuals.

What are different types of pain medicines?

 If we talk about pain medications, they are categorized in three main groups stated below:

Over-the-counter or OTC medicines

These types of medications usually include NSAIDs and acetaminophen. They are easily available without a prescription from a doctor.

Over-the-counter or OTC medicines are suitable for treating mild to moderate pain.

Prescription NSAIDs

Some stronger NSAIDs such as celecoxib and diclofenac might require a prescription from a doctor for pain management.

They are effective in treating more serious pain and various inflammatory conditions.

Prescription opioids

Prescription opioids usually range from codeine to fentanyl and are prescribed strictly for treating acute pain.

Doctors generally give prescription opioids to patients suffering from cancer-related pain or experiencing post-surgery pain.

Due to potential for misuse of prescription opioids, they are monitored by doctors closely.

Pain relieving medicines: Know their working mechanism

Depending on class of medicine, mechanism of action of each type of pain reliever differs.

Let us understand working mechanism of three main classes of pain medicines:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Opioids
  • Acetaminophen
  • Nonsteroidal anti-inflammatory drugs (NSAIDs)

NSAIDs work in your body by inhibiting enzymes known as cyclooxygenases, especially COX-1 and COX-2.

These enzymes are further responsible for producing prostaglandins which are hormone-like substances responsible for inflammation, pain & fever.

Nonsteroidal anti-inflammatory drugs further block production ofprostaglandins which cause decreased inflammation and pain.


Opioids work in body by binding to particular receptors present in your brain, peripheral tissues, and spinal cord called opioid receptors.

You need to know that some major types of opioid receptors include mu, delta, and kappa.

When opioids bind to these receptors, transmission of pain signals is disturbed and perception of pain is altered.

Activation of mu receptors offer effective pain relief but it’s also linked with side effects like euphoria & respiratory depression. 

One can also develop physical dependence if opioids are taken more often than directed by a doctor.


Though exact working mechanism of acetaminophen is not understood completely.

It is believed to affect endocannabinoid system in your brain that plays a role in your pain perception, appetite, and mood.

Moreover, acetaminophen can hinder an enzyme in your brain that is involved in synthesis of prostaglandins.

Unlike NSAIDs, acetaminophen causes minimal anti-inflammatory effects and mainly reduces your fever & pain.

What are side effects of pain relievers?

Before you start treatment with any of these pain relievers, it is important to know about their side effects.

Pain medicines just like other drugs also come with a few side effects which can be managed.

Seriousness and likelihood of these side effects of depend upon various factors like dosage, type of medicine, and length of treatment.

Below-stated are some common side effects linked with different classes of pain drugs:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Might irritate your stomach lining and cause symptoms like stomach pain, heartburn, or ulcers.
  • Gastrointestinal bleeding ulcers
  • Kidney function might be affected, causing fluid retention & increased blood pressure
  • Allergic reactions like facial swelling, skin rashes, or wheezing.


  • By slowing down movement of your digestive tract, Opioids can cause constipation
  • nausea and vomiting when starting treatment with opioids
  • impair coordination and drowsiness
  • high doses or misuse of opioids cause slowed breathing
  • Physical dependence and addiction in some people


  • Overdose of acetaminophen or combining it with alcohol causes liver damage or failure
  • Skin reactions or serious allergic responses

Thus, with proper consultation, you must first understand pain relievers and then start treatment accordingly.

Copyright © All Rights Reserved.