Simple analgesics (non-opioid analgesics)

• What are simple analgesics?
• What are simple analgesics used for?
• How do the simple analgesics work?
• Precautions
• Side effects of simple analgesics

What are simple analgesics?

Simple or non-opioid analgesics are a diverse group of drugs that include anti-inflammatory drugs (non-steroidal anti-inflammatory drugs or NSAIDs) and paracetamol.

Most anti-inflammatory drugs also have the ability to relieve fever and antiplatelet (anti-clotting) properties. Paracetamol has the ability to reduce fever, but has minimal anti-inflammatory effects and no effect on blood clotting. Paracetamol is the preferred option for fever and mild-to-moderate pain as it has fewer adverse effects.

What are simple analgesics used for?

NSAIDs, including aspirin, are indicated for:

• Fever
• Mild-to-moderate pain due to inflammation and tissue injury
• Migraine and tension headache
• Period pain
• Pain caused by bone cancer
• Rheumatoid arthritis, including juvenile rheumatoid arthritis
• Osteoarthritis
• Rheumatic fever
• Pain caused by an attack of gout (not aspirin)

Paracetamol is indicated for:

• Mild-to-moderate pain
• Fever
• Migraine and tension headache

How do the simple analgesics work?

Anti-inflammatories relieve pain and inflammation within the body by decreasing the production of pro-inflammatory chemicals known as prostaglandins. Prostaglandins are normally produced in response to tissue damage, and are known to play a major role in the processes of inflammation, pain and fever.

Paracetamol also works by reducing the synthesis of prostaglandins.

Precautions

Asthmatics:

• In some asthmatics anti-inflammatory medicines can trigger an asthma attack.
• If you suffer from asthma you should consult your doctor before taking any non-steroidal anti-inflammatory medication.

Crohn’s disease:

• Crohn’s disease can be exacerbated by anti-inflammatory medication.
• If you suffer from Crohn’s disease you should consult your doctor before taking any non-steroidal anti-inflammatory medication.

History of peptic ulcer disease (stomach ulcers):

• Anti-inflammatory medication can increase the risk of further ulceration or bleeding.
• If you have a history of peptic ulcer disease you should consult your doctor before taking any non-steroidal anti-inflammatory medication.

Heart Failure and High Blood Pressure:

• Heart failure and high blood pressure may be exacerbated with the use of anti-inflammatories.
• If you suffer from heart disease or high blood pressure you should consult your doctor before taking any non-steroidal anti-inflammatory medication.

Pregnancy:

• Non-steroidal anti-inflammatories are ADEC pregnancy category C.
• Before taking anti-inflammatory medication pregnant women, should discuss the benefits and risks with their doctor.

Breastfeeding:

• For the effects of Statins on breastfeeding, consult your healthcare professional.

Children

• Children under 18 years should not use aspirin as there is a risk of Reye’s syndrome.

Paracetamol

Pregnancy and breastfeeding:

• Safe to use
• ADEC category A

Side effects of simple analgesics

NSAIDS: Most common side effects are mild. Listed below are the common (≥1%) and infrequent (<1%) side effects of non-steroidal anti-inflammatory medications (NSAIDS). You may not experience any side effects.

Common:

• Nausea, dyspepsia
• Ulceration or bleeding of the stomach or intestines
• Diarrhoea
• Headache
• Dizziness
• Salt and fluid retention(oedema)
• High blood pressure

Uncommon:

• Ulceration of the oesophagus
• Rectal irritation (with suppositories)
• Heart failure
• Confusion
• Asthma attacks
• Rash

Speak to your doctor if you experience or are concerned about any of these or other side effects.

Paracetamol: Reports of side effects are rare at recommended doses. The following side effects have been reported:

• Dyspepsia
• Allergic reactions and blood disorders

Speak to your doctor if you have any concerns regarding the use of paracetamol.

References

1. Australian Medicines Handbook. Non-opioid analgesics[online]AMH Pty Ltd 2007[cited Feb 8, 2008] http://www.amh.net.au
2. MIMs Online. [online]MIMS Australia Pty Ltd 2007.[Cited Feb 8, 2008] http://www.mims/com.au