Objective: Perform an economic evaluation of alverine citrate/simethicone for the treatment of irritable bowel syndrome (IBS) from the perspective of the National Health System (NHS) in Mexico.

Methods: A systematic review of the clinical literature was conducted to evaluate the efficacy and safety of alverine citrate/simethicone compared to pinaverium bromide and butilhyoscine bromide. With the information obtained, an economic evaluation of cost-effectiveness was carried out using a decision tree model using a time horizon of 2 months. The measure of efficacy is expressed as the probability of overall improvement in IBS (Martínez-Vázquez, 2012). We considered the direct medical costs related to the treatment of each of the interventions that were obtained from NHS purchasing portals in Mexico.

Additionally, a budget impact analysis was carried out to calculate the financial impact of alverine citrate/simethicone in the NHS of Mexico. The analysis was performed over 5 years.

Results: The average cost per patient treated with alverine citrate/simethicone was $1,442.61MxN with an efficacy of 0.638. Pinaverium bromide and butylhyoscine bromide have an average cost per patient of $170.99 and $276.92 MXN with the efficacy of 0.597 and 0.609.

Alverine/simethicone citrate is a "cost-effective" option over butylhyoscine bromide and pinaverium bromide with an ICER of $41,181.73 MXN and $31,085.80 MXN respectively.

The inclusion of alverine citrate/simethicone in the NHS would imply an average financial impact over 5 years expressed as a percentage of the NHS drug budget of 0.096%.

Conclusions: Alverine citrate/simethicone for the treatment of patients with IBS, is a cost-effective option within the cost-effectiveness threshold established in Mexico against butylhyoscine bromide and pinaverium bromide.