Relationship between the Price & Quality of Medicines: Narrative Review

Abstract

One medicine can appear in a range of prices in the market. Given the perception that expensive products are superior in quality compared to their generic counterparts has led to poor drug substitution practices. This narrative review aimed to investigate the relationship between the price and quality of medicines using in-vitro and in-vivo studies conducted on differently priced products. A literature search was conducted to find original research articles written in English and published from January 2000 to June 2021 using Scopus, PubMed, and Google scholar. Studies that did not report in-vitro or in-vivo quality control test results against the price of the products were excluded. Contents were explored, extracted, analysed, and evaluated to find any relationship between the price of a drug product to its quality. Thus, sixteen articles were reviewed [Group I- In-vitro quality & price of medicines (n=11), and Group II- In-vivo quality of different medicines (n=5)]. All the studies were conducted on tablets and capsules. Eight in-vitro studies confirmed that all the tested medicines were up to the expected quality, irrespective of the price. Rest (n=3) of the in-vitro studies reported quality failures indicating that low and middle-income countries might have poor-quality drugs with lower prices. Among the in-vivo studies (n=5), three articles supported the idea of generic substitution. The other two articles reported that generics were not bioequivalent and suggested monitoring the therapy during & after the substitution of generic medicines. Moreover, poor quality was reported for antibiotics, antipsychotics, and antidiabetic tablets. Even though the majority (n=11) of the articles supported the idea that quality does not depend on the price of medicines, it is difficult to generalize the idea, given the difference in the quality tests reported in studies. The scarcity of in-vivo studies limits the outcomes of this review.