analgesics:

non-steroidal anti-inflammatories (nsaid)

Written by Chloe Doris

Last Reviewed: September 2019

Review Due: September 2020

examples1

Ibuprofen

Diclofenac

Naproxen

Aspirin

 

mechanism of action2

In regular full dosage, NSAIDs have both an analgesic and an anti-inflammatory effect.

 

Prostaglandins act to sensitise nociceptors to inflammatory mediators such as bradykinin. NSAIDs decrease the production of prostaglandins by inhibiting the enzyme cyclo-oxygenase (COX) and thus decrease the sensitisation of nociceptors.


There are 2 isoforms of COX – COX1 and COX2. NSAIDs vary in their selectivity for inhibiting different types of COX – selective inhibition of COX-2 is associated with less GI intolerance. Aspirin blocks both COX1 & 2 and therefore has a stronger response.

 

indications1

Mild to moderate pain (including post-operative, migraine & dental)

Pain and inflammation of soft tissue injuries

Pain and inflammation in rheumatic disease and other MSK disorders

Pyrexia with discomfort

 

side effects1

Respiratory depression

Dependence or withdrawal

Arrhythmias

Confusion

Constipation, GI discomfort, reduced appetite

Dizziness, drowsiness, dry mouth

Euphoria

Hallucination

Palpitations

 

Contraindications1

History of hypersensitivity to aspirin or any other NSAID.

​

To be used with caution in children, depending on drug. For example, aspirin should not be used in children in under 16 due to risk of Reye's syndrome.


With systemic use: active GI bleeding, active GI ulceration, history of GI bleeding or perforation related to NSAIDs, history of recurrent GI haemorrhage or ulceration, severe heart failure or varicella infection are contraindications to NSAIDs. 

 

dose adjustments1

Hepatic Impairment 

Prescribe with caution in mild to moderate impairment, avoid in severe impairment


Renal Impairment

Avoid if possible or use with cautio, avoid in severe renal impairment1

 
 

interactions3

Warfarin

Ciclosporin 

Diuretics

Lithium

Methotrexate

SSRIs

counselling1

In topical use – patients should wash hands immediately after use and also be advised against excessive exposure to sunlight of the area treated to avoid possible photosensitivity.

 

REFERENCES

  1. British National Formulary. Morphine. (2019)

  2. Rang H.P, Ritter J.M, Flower R.J, Henderson G. Rang & Dale’s Pharmacology. 8th Ed. Elsevier Churchill Livingstone; 2016. Page 519.

  3. British National Formulary. Interactions: Morphine. (2019)