Pharmacology encompasses the study of drugs that act on the respiratory system, including anti-asthmatic drugs, which alleviate symptoms of asthma, and drugs used in the management of chronic obstructive pulmonary disease (COPD), aimed at improving airflow and reducing exacerbations. Expectorants and antitussives help manage cough by promoting mucus clearance or suppressing the cough reflex, while nasal decongestants relieve nasal congestion. Respiratory stimulants are used to stimulate breathing in conditions where respiration is compromised. In the gastrointestinal tract, antiulcer agents protect the stomach lining and treat peptic ulcers, while drugs for constipation and diarrhea address bowel movement irregularities. Appetite stimulants and suppressants regulate hunger and satiety, and digestants and carminatives aid in digestion and reduce gas formation. Emetics induce vomiting in cases of poisoning, whereas anti-emetics prevent nausea and vomiting.
Chemotherapy involves the use of drugs to combat infections and diseases, adhering to principles that ensure efficacy and minimize resistance.