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.
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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
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British National Formulary. Morphine. (2019)
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Rang H.P, Ritter J.M, Flower R.J, Henderson G. Rang & Dale’s Pharmacology. 8th Ed. Elsevier Churchill Livingstone; 2016. Page 519.
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British National Formulary. Interactions: Morphine. (2019)