Table 1.

Comparison of medications known to contain NDMA

Medication	Highest NDMA level, µg, per dose	Maximum daily dosing, mg	Cause of NDMA	FDA response
Ranitidine	0.86 per 300 mg	300	Undetermined but increases with application of heat	Complete market withdrawal
Nizatidine	0.02 per 150 mg	300	Undetermined	Voluntary recalls of affected products
Irbesartan	Unpublished	300	Manufacturing process	Voluntary recalls of affected products
Losartan	Unpublished	100	Manufacturing process	Voluntary recalls of affected products
Valsartan	20.19 per 320 mg	320	Manufacturing process	Voluntary recalls of affected products
Metformin a	0.19 per 500 mg	2000	Undetermined	Voluntary recalls of affected products

Comparison of NDMA levels of affected medications and cause of impurity as reported by the FDA as well as agency response. ⁴ , ⁶ , ⁸ Typical maximum daily dosing of oral products is reported.

Abbreviations: FDA, US Food and Drug Administration; NDMA, N‐nitrosodimethylamine.

^a Extended‐release formation.