A vast majority of the most frequently prescribed medications contain at least one ingredient capable of causing an adverse allergic reaction, a US study has found. Known as inactive ingredients, these components are added to improve the taste, shelf-life, absorption and other characteristics of a pill, but the researchers found that more than 90 per cent of all oral medications tested contained at least one ingredient that can cause allergic or gastrointestinal symptoms in sensitive individuals. Such ingredients include lactose, peanut oil, gluten and chemical dyes, scientists said. “When you’re a clinician, the last thing you want to do is prescribe a medication that could cause an adverse reaction or allergic reaction in a patient,” said C Giovanni Traverso, from Massachusetts Institute of Technology (MIT). “This project was inspired by a real-life incident where a patient with Celiac disease was prescribed a medication and the formulation of the pill they picked up from the pharmacy had gluten in it,” Traverso said.”We wanted to understand the problem and drill down to characterise the entire universe of inactive ingredients across thousands of drugs,” he said. Researchers analysed data on the inactive ingredients found in 42,052 oral medications that contained more than 354,597 inactive ingredients. Inactive ingredients are defined as substances that are added to a pill’s formulation but are not intended or expected to have a direct biological or therapeutic effect. Although such ingredients have been tested for safety at the population level, scattered case reports have suggested that inactive ingredients may cause adverse reactions in individuals who have allergies or intolerances. “There are hundreds of different versions of pills or capsules that deliver the same medication using a different combination of inactive ingredients,” said Daniel Reker, a postdoctoral fellow at MIT.”This highlights how convoluted the possible choices of inactive ingredients are, but also suggests that there is a largely untapped opportunity today to specifically select the most appropriate version of a medication for a patient with unusual sensitivities,” Reker said.
