Pharmacovigilance & Drug Safety

Diclofenac is a most commonly used NSAID for pain and inflammatory management. Diclofenac has an equipotential inhibitory action on Cyclooxygenase (COX) 1 and 2 enzymes, there by hindering prostaglandin production. In a hospital setting it is administered through Intramuscular (IM), Intravenous (IV), transdermal, oral and rectal routes. Although, the medication is considered as an appropriate option to treat post-operative pain, it is associated with morbid syndromes like Kounis and Nicolau along with gastrointestinal, hepatic, neurological, renal and respiratory adverse effects. The immunological adverse effects are comparatively underreported and among those reported anaphylactic reactions associated with IM and rectal routes of administration of diclofenac are common, whereas, IV and oral route diclofenac allergies are rare. The case report series of diclofenac allergy by IV and oral diclofenac administration are reported here. In either cases patient developed drug induced hypersensitivity reaction as soon as the drug administered, causality assessment is performed in both the cases and concluded that the reaction was moderate and definitely preventable in one as the patient informed of a similar reaction in past after diclofenac injection and in the other case the causality assessment stated the reaction was moderate and not preventable as patient has no past history. Thus, our paper concludes by saying adverse effects of diclofenac include angioedema usually quite self-limiting, though it is proven to be fatal at times. Thus, the condition should be identified early and the offending agent should be removed. Corticosteroids antihistamines can be useful in management. Healthcare professionals should keep in mind the possible adverse reactions of the diclofenac and the patient should be well enquired about reaction history or to be informed regarding the adverse reaction caused by the drug before prescribing and dispensing it.