Tolerance Assessment of paracetamol in patients with pharmacological hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs)

Ferdaous Chahed (Monastir, Tunisia), Najah Ben Fadhel (Monastir, Tunisia), Amel Chaabane (Monastir, Tunisia), Haifa Ben Romdhane (Monastir, Tunisia), Karim Aouam (Monastir, Tunisia), Nadia Ben Fredj (Monastir, Tunisia)

Background

Paracetamol is one of the most popular and commonly used analgesics and antipyretic drugs worldwide and it is considered as a well-tolerated drug. Cross-reactivity to paracetamol in patients with prior pharmacological reaction(intolerance) to NSAIDs is rarely studied. The objective of this study is to assess tolerance to paracetamol in patients with a confirmed pharmacological hypersensitivity reaction to one or more NSAIDs.

Method

A descriptive study was conducted at the Department of Clinical pharmacology of Monastir (Tunisia) during a period of 16 years and validated according to the Begaud et al.method. All patients who had an intolerance to NSAIDs were included. Tolerance to paracetamol was evaluated prospectively via a questionnaire and allergological explorations

Results

OPT to paracetamol was carried out in 84 patients with a confirmed intolerance to NSAID. Paracetamol intolerance was confirmed in 11 patients (13%). The median age of these patients was 46 years [range:37-50] with a female predominance (SR (F /M: 9/2). Atopy was identified in seven patients (63.6%). Five patients had at least 2 episodes of NSAID tolerance. Symptoms occurring during OPT to paracetamol are similar to the initial episode of intolerance reaction with NSAIDs. The delay between the paracetamol intake and hypersensitivity reactions was immediat in eight patients. NSAIDs previously offended were aryl carboxylic acids in ten cases, followed by salicylates in seven cases. Seven patients have shown an anaphylactic reaction after paracetamol OPT. A prior history of anaphylactic reactions with NSAIDs and underlying atopy have been reported as risk factors for cross-reactivity to paracetamol. The provocative dose was ranged between 100mg and 2000mg. The ROC curve analysis of the dosage of paracetamol was carried out using the dosages relating to 84 patients included. The area under the curve (sensitivity_100-specificity) is 0,83 (95% CI: 0,67-1, p = 0,0001). The threshold value of the dosage of paracetamol associated with the occurrence of hypersensitivity is 1000 mg (sensitivity:95,9% and a specificity of 72,7%).

Conclusion

paracetamol can induce cross-reactivity in a significant proportion of patients with HS to NSAIDs and prevalence varies depending on the initial episode of hypersensitivity to NSAIDs.