FRANKFURT: Bayer said it had received a warning letter from the US Food and Drug Administration over how it handled production of some drugs at its Leverkusen, Germany headquarters.
The German drugmaker, which is taking over US seed maker Monsanto, is addressing the FDA's complaints regarding manufacturing practices, which stem from a routine inspection in January, Bayer said.
It has no evidence that patient safety was or is at risk and no products would be recalled, it added.
"We expect temporary supply limitations affecting our mature product portfolio," though distribution from the Leverkusen supply centre would continue, Bayer said.
A spokesman said this was affecting the established drugs Adalat against high blood pressure, blood thinner Aspirin Cardio, antibiotic Avelox, and potency drug Levitra.
Citi analysts said in a research note that the products accounted for 2017 sales of about 2 billion euros (US$2.5 billion), about 6 per cent of the group total.
"The business impact will be reflected in our upcoming 2018 guidance on February 28," Bayer said.