Imagine you hurt your thumb by hitting it with a hammer. Pain sensors at the site of the injury (also known as nociceptors), immediately generate a pain signal which is sent along a pathway of nerves, through the spinal cord and up to your brain.¹ This is known as the ascending pain pathway.¹

Here, the message is relayed to the different parts of the brain that are responsible for the perception of pain, as well as various physical reactions such as a rise in blood pressure and fast breathing.¹ It's only now that your body registers the sense of pain.¹

At the same time, your brain reduces the perception of pain by activating the descending pain pathways:¹

1. It secretes opioids that block pain transmission in the spinal cord
2. It sends a signal down the spinal cord that activates the secretion of noradrenaline, another substance that blocks the transmission of pain signals

Adapted from Von der Laage D, 2013¹

The quality of pain we feel depends on where it comes from. Superficial pain that originates in the skin, e.g. a needle prick, is sharp and easily located.¹ On the other hand, pain that originates from deeper structures, such as bone, joints, and muscle, feels dull, often radiates to the surrounding area and is difficult to localise.¹ Pain that originates from our intestines tends to be dull and colicky, with accompanying symptoms such as nausea.¹

Pain may be acute or chronic.² Acute pain begins suddenly and does not last longer than 3 months.² It arises as a consequence of injury or disease and has a warning function.¹ Chronic pain lasts for months or years and may result in other problems, such as depression and disturbed sleep.² Unlike acute pain, chronic pain has lost its warning function and is due to a malfunction of the nervous system.¹

Pain that arises from stimulation of nociceptors is described as nociceptive pain.² Most pain, particularly acute pain, is nociceptive pain.² Examples are pain after surgery, broken bones, skin injury or joint diseases.¹

Pain that results from damage to nerves is described as neuropathic pain.² Neuropathic pain is commonly of a shooting, burning or stabbing nature and tends to become chronic.¹

Pain can have a big impact on your daily life.³ It can interfere with your ability to do your daily activities.³ Pain can sap your energy, leaving you feeling drained and unwell.³ The more severe the pain, the greater the impact.³

Fortunately, there are different treatment options available to manage pain, including analgesics. Let us take a closer look at the relief provided by analgesics.

Analgesics can be broadly classified into 3 groups:⁴

• Non-opioid analgesics: they work in a different manner to opioids to relieve pain, e.g. paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs).
• Opioid analgesics: they bind to opioid receptors to relieve pain, e.g. codeine and morphine.
• Co-analgesics: their primary indication is not for pain, e.g. anti-epileptic drugs and anti-depressants, but they do relieve pain in conditions such as chronic or neuropathic pain.

How analgesics work to relieve pain

Analgesics relieve pain by their effects on the ascending and descending pain pathways.⁵ Let's focus on the main types of analgesics used to treat pain, namely opioid and non-opioid analgesics.⁶

Non-opioid analgesics

Paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) are the main types of non-opioid analgesics and are effective for mild to moderate pain.⁶ Non-opioid analgesics relieve different types of pain (e.g., trauma, postoperative, cancer, arthritis pain) and are especially effective for certain types of deeper pain (e.g., muscle and joint pain, bone/dental pain, inflammatory pain, postoperative pain).⁴

NSAIDs work by inhibiting the synthesis of prostaglandins, which are responsible for the development of pain. Examples include ibuprofen and diclofenac.⁶

Paracetamol has been a mainstay of pain relief and fever control since the 1960's.⁷ Paracetamol is thought to elevate the pain threshold by blocking the release of pain causing substances in the spinal cord and brain.⁸

Non-opioid analgesics do not cause physical dependence or tolerance.⁶

Opioid analgesics

Opioid analgesics bind to opioid receptors to inhibit the transmission of pain signals generated by the nociceptors at the site of pain, as well as activate the descending pain pathways that inhibit pain.⁴ Therefore, opioids modify the sensation and perception of pain.⁴ Nearly all types of pain respond to opioids, however nociceptive type of pain responds better than neuropathic pain, which may require higher doses of opioids.⁴ Opioids play a major role in the treatment of acute pain (e.g. trauma, postoperative pain), breakthrough pain, cancer pain, and some types of chronic noncancer pain.⁴ Opioids are classified as weak, e.g. codeine, or strong, e.g. morphine.⁴

Combination analgesics

No single analgesic can treat all types of pain.⁷ Therefore, when combining two or more analgesics that work differently, there is a greater chance that pain signals will be interrupted and pain will be relieved.⁵ The combination will target multiple pain pathways for the relief of a broader spectrum of pain and might also reduce the risk of adverse effects.⁷

For example, a combination of codeine, paracetamol and ibuprofen acts synergistically, allowing for greater pain relief than if the analgesics were used separately.^7,9 This combination also targets pain, inflammation and fever simultaneously and may lower the risk of adverse effects because lower doses of each individual component are needed compared to using the three separately.^9,10

Ask your doctor or pharmacist about the triple combination analgesic from Adcock Ingram that has been trusted to relieve pain for over 30 years.¹⁰