Senators Call for New Limits on 'Medically Important' Antibiotics

A new bill introduced this week in the US Senate would restrict the use of "medically important" antibiotics in agriculture in the hopes of reducing the risk of bacteria developing resistance to those drugs.

Background

The bill, the Preventing Antibiotic Resistance Act (PARN) (PDF), was introduced on 2 March 2015 by Sens. Dianne Feinstein (D-CA) and Susan Collins (R-ME), with support from Sens. Kirsten Gillibrand (D-NY) and Elizabeth Warren (D-MA).

The legislation is the latest in long line of legislative efforts meant to confront resistance. Since 2012, legislators have introduced at least a dozen bills related to developing new antibiotics or safeguarding the effective use of existing antibiotics. (See the end of this article for a complete list)

The bill is in fact similar to one introduced in 2013 by Feinstein, which was also intended to restrict the use of antibiotics.

As with the old bill, Feinstein and Collins' latest effort focuses on the use of antibiotics in agricultural settings.

"The Centers for Disease Control and Prevention, CDC, estimate that antibiotic-resistant bacteria cause at least 23,000 deaths and 2 million infections each year in the United States. The CDC also estimates that antibiotic resistance costs the United States $20 billion in excess health costs each year," Feinstein said in remarks earlier this week. "These statistics will only worsen if we do not take meaningful steps to reduce inappropriate and unnecessary antibiotic use."

Combatting Resistance

The PARN Act would take those "meaningful steps" by preventing some "medically important" antibiotics from being used in food-producing animal populations. Any New Animal Drug Application (NADA)—the application used by FDA to approve new veterinary drugs—for a medically important antibiotic that fails to demonstrate that it would not contribute to antibiotic resistance could be rejected by FDA.

"Medically important" antimicrobials include penicillin, tetracycline, macrolide, lincosamide, streptogramin, aminoglycoside, sulfonamide, cephalosporin, fluoroquinolone, and any drug listed as ‘highly important’, ‘critically important’, or ‘important’ by the World Health Organization (WHO).

Drug sponsors will be required to, as of 1 January 2018, submit data indicating:

• there is evidence of effectiveness in controlling or preventing bacterial disease
• an approved use is consistent with accepted veterinary practice
• an approved use is linked to a specific etiologic agent
• an approved use is appropriately targeted to animals at risk of developing a specific bacterial disease
• an approved use has an explicitly defined duration of therapy
• there is reasonable certainty of no harm to human health due to the development of antimicrobial resistance

FDA would then be tasked with either updating the labels of animal antibiotics to reflect their appropriate uses, or removing from the market any drugs which fail to provide sufficient evidence under the above criteria.

The bill has won praise from the Pew Charitable Trusts, which said it would "ensure that antibiotics are used appropriately based on the best available evidence."

Other Antibiotic Legislation