The maker of Robitussin is recalling several lots of cough syrup due to contamination that could pose a serious risk to people with weakened immune systems.

(CNN) – Parents take note: GlaxoSmithKline Consumer Healthcare has voluntarily recalled three lots of its children's cough syrups — Children's Robitussin Honey Cough and Chest Congestion DM and Children's Dimetapp Cold and Cough — due to the products having incorrect dosing cups in their packaging. GlaxoSmithKline found that the cups for Children's Robitussin Honey cough syrup were missing lines for the 5-milliliter and 10-milliliter graduations and the cups for Children's Dimetapp were missing the 10-milliliter graduation. They include:Lots "02177" and "02178" for Children's Robitussin Honey Cough and Chest Congestion DM (4 ounces), expiring January 2022. However, in children, cough may not be the first symptom. Studies have compared honey with some of the over-the-counter cough medicines and found it works just as well."