The nursing instructor is teaching about antitussives and their side effects. what ingredient found in some antitussives does the instructor tell students can cause drowsiness?

antihistamine

Explanation:

Antihistamines are the drugs which are used to treat allergies, congestion, sneezing caused by dust, pollen and insect bite.

These are the suitable drugs for inducing sleep and drowsiness. These have powerful sedating features. These are the active ingredients found in counter sleep aids.

Antitussives are the medicines that suppress coughing. These will inhibit coordinating region of the brain.

Antihistamines are the components of antitussives which suppress the functions of the brain and causes drowsiness.

                                                        water

a colorless, transparent, odorless, tasteless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.

                                                        halon  

any of a number of unreactive gaseous compounds of carbon with bromine and other halogens, used in fire extinguishers, but now known to damage the ozone layer.

                                                  dry chemical

extinguishing agent used on class a, class b, and class c fires.

                                                  carbon dioxide

a colorless, odorless gas produced by burning carbon and organic compounds and by respiration. it is naturally present in air (about 0.03 percent) and is absorbed by plants in photosynthesis.