Telling me some random generic has gone up in price means nothing to me . For all I know, that might be an old fashioned drug hardly any doctors prescribe and the price increases is required in order to keep it available for the few people who require it... or it could just as easily mean the company has a monopoly and is price gouging consumers.
There needs to be a weighted index, or multiple indexes, of drugs weighted by how important they are. Not sure how to define importance in this context, but quantity sold would be a good start, maybe another index weighted by average expenditure per patient per year and another weighted by lives saved.
Edit: Downvoters, I did read the article. An unweighted group of any product is not very useful from an economics perspective. That is why the CPI is weighted.