September 02, 2019
I’m an old, but still widely used, antibiotic.
What molecule am I?
Image of Nitrofurantoin 3D Image of Nitrofurantoin

Nitrofurantoin is an antibacterial medication used primarily to treat urinary tract and bladder infections. It has been sold under more than two dozen trade names, including Macrobid; but it is now almost always supplied as a generic.

The first US patent on the synthesis of nitrofurantoin was awarded in 1952 to Kenyon J. Hayes at the long-defunct Eaton Laboratories1 (Norwich, NY). The drug was introduced in 1953. In his 2015 book Basic Principles of Drug Discovery and Development, Benjamin E. Blass called nitrofurantoin “a surprisingly successful drug” because of its market longevity.

In 2018, a controversy erupted over the cost of the liquid formulation of nitrofurantoin. The only two US companies that produce the formulation, Nostrum Laboratories (Kansas City, MO) and Casper Pharma (East Brunswick, NJ), dramatically increased their prices: Nostrum, from the already expensive US$475 per bottle, to $2,393 and Casper to $2,800. Needless to say, an uproar ensued, heightening demands for pharma industry price reforms, an issue of much concern in the US Congress and elsewhere.

1. You can purchase vintage postcards of the Eaton buildings on Amazon and other online sellers.

Nitrofurantoin hazard information

GHS classification*: acute toxicity, oral, category 4
H302—Harmful if swallowedChemical Safety Warning
GHS classification: skin sensitization, category 1
H317—May cause an allergic skin reactionChemical Safety Warning
GHS classification: respiratory sensitization, category 1
H334—May cause allergy or asthma symptoms or breathing difficulties if inhaledChemical Safety Warning

*Globally Harmonized System of Classification and Labeling of Chemicals. Explanation of pictograms.

Nitrofurantoin fast facts

CAS Reg. No.67-20-9
Empirical formulaC8H6N4O5
Molar mass238.16 g/mol
AppearanceYellow to orange crystals or powder
Melting point≈272 ºC (dec.)
Water solubility80 mg/L
Chemical Abstract Service - a division of ACS

Learn more about this molecule from CAS, the most authoritative and comprehensive source for chemical information.

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