WHO Essential Medicines List Adds New Drugs, Categorizes Antibiotics

When the World Health Organization (WHO) updates its Essential Medicines List every 2 years, observers anticipate the addition of some new drugs or alternate indications. The 20th edition, released Tuesday, also includes a more drastic change by categorizing antibiotics.

Amid widespread efforts to curb antibiotic overuse and prevent bacterial resistance to the drugs, the WHO is attempting to guide clinicians toward using different antibiotics for appropriate infections. The goal of the new categorization is to “enhance treatment outcomes, reduce the development of drug-resistant bacteria, and preserve the effectiveness of ‘last resort’ antibiotics that are needed when all others fail,” according to a press statement on the updated list’s release. Antibiotics are now sorted into 3 categories:

1. Access. These antibiotics are widely used to treat numerous common infections, like amoxicillin to treat pneumonia, and should be available and affordable at all times.
2. Watch. These antibiotics have higher resistance potential and should be considered first- or second-line treatments for a select few infections. For instance, clinicians should aim to curtail the use of ciprofloxacin to treat cystitis or upper respiratory tract infections.
3. Reserve. These antibiotics, which include colistin and daptomycin, should only be used as a last resort when all other alternatives have failed in severe circumstances such as life-threatening infections caused by multi-drug resistant bacteria. Antibiotics in the latter 2 groups should be a target of responsible drug stewardship programs aiming to correct the misuse of such medicines, the list noted.

"The new WHO list should help health system planners and prescribers ensure people who need antibiotics have access to them, and ensure they get the right one, so that the problem of resistance doesn’t get worse,” said Dr Suzanne Hill, director of essential medicines and health products, in the press release.

The antibiotic categories weren’t the only changes to the list since its last iteration published in 2015. Its roster of 433 essential drugs now includes some novel drugs like 2 oral cancer therapies and a new combination therapy for treating hepatitis C. It has also added fentanyl and methadone for the management of cancer pain, even as fentanyl has been blamed for a sharply rising rate of overdoses caused by synthetic opioids in the United States.

Just as notable as the new additions are the absences of medicines some had speculated would join the line-up of essential medicines. The WHO had received requests to include long-acting insulin analogs on the list, but the newly released formulary omits these and keeps only intermediate-acting insulin and soluble insulin injections.

Nonprofit organization Health Action International applauded the decision in a press release, arguing that incorporating the long-acting analogs into the list would have driven up prices and caused access to shrink.

“A positive decision would have encouraged national governments to buy long-acting analogue insulin — which has a median price that is seven to nine times higher than human insulin, but has limited added therapeutic value,” said Margaret Ewen, PhD, in the statement. “The result would have been fewer people being treated and more deaths.”

Ewen was a co-lead of the Addressing the Challenge and Constraints of Insulin Sources and Supply (ACCISS) study, which examined insulin access worldwide and found that the long-acting analogs, glargine and detemir, were unaffordable by the WHO’s standards, as they cost over 8 days’ wages for a low-paid unskilled worker to buy a month-long supply.