Respiratory System Drugs Quiz

Respiratory System Drugs

• Respiration is the exchange of gases between the atmosphere and the body's cells.
• Ventilation is the process of bringing fresh air into the body.
• Upper respiratory tract includes the nares, nasal cavity, pharynx, and larynx.
• The upper respiratory tract is lined with epithelial cells containing cilia.
• Cough receptors are primarily located in the pharynx and trachea.
• Diseases of the upper respiratory tract include congestion, sneezing, and coughs.
• The lower respiratory tract includes the trachea, bronchi, bronchioles, and alveoli.
• Bronchioles have smooth muscle, with sympathetic stimulation causing relaxation (bronchodilation) and parasympathetic stimulation causing contraction (bronchoconstriction).
• Alveoli produce surfactant to keep them open, and diseases include asthma, bronchitis, pneumonia, and recurrent airway obstruction (ROA), including heaves in horses.
• Expectorants increase the flow of respiratory secretions, making material easier to cough up.
• Guaifenesin increases respiratory secretions and is used as a muscle relaxant in horses (triple-drip).
• Adverse effects include mild decreases in blood pressure and increased heart rate.

Mucolytics

• Mucolytics decrease the viscosity of respiratory secretions.
• Acetylcysteine is used to treat acetaminophen toxicity in cats and prevent corneal damage in horses.
• Possible side effects include vomiting and hives (rarely), and chest tightness/irritation in the lower respiratory tract.

Antitussives

• Antitussives suppress coughs, but productive coughs are not always suppressed.
• Anti-tussives can act centrally (on brain stem centers) or locally (on mucosal linings).
• Opioids, Butorphanol, Hydrocodone, Codeine are centrally acting antitussives and can cause respiratory depression.
• Dextromethorphan is an OTC cough medication chemically similar to cocaine.

Decongestants

• Decongestants reduce nasal swelling.
• Many come in sprays, liquids, or tabs (PO).
• Decongestants are used to reduce nasal swelling by decreasing inflammation of the mucosal lining or reducing swelling, reducing congestion or swelling.
• Phenylephrine and pseudoephedrine are used; the latter may be combined with antihistamines.

Bronchodilators

• Bronchodilators widen the airways counteracting bronchoconstriction, produced by stimulating the sympathetic nervous system or by suppressing the parasympathetic nervous system.
• Examples of Bronchodilators include: Epinephrine, Isoproterenol, Terbutaline, and Albuterol.
• Beta-2-adrenergic agonists stimulate the Beta-2 receptors in the sympathetic nervous system, involved in bronchodilation and mast cell stabilization.
• Methylxanthines (Aminophylline, Theophylline) also have bronchodilating effects but also inhibit an enzyme in smooth muscle.
• Adverse effects include nausea, vomiting, CNS stimulation (Increased heart rate).
• Antihistamines bind with H1 receptors to cause bronchodilation, decreased HR, vasodilation, CNS sedation, and inhibit inflammation response.
• Ex: Diphenhydramine & Chlorpheniramine.
• The side effects for antihistamines include CNS depression and anticholinergic effects, such as dry mouth & urinary retention.

Respiratory Stimulants

• Respiratory stimulants stimulate respiration, such as Doxapram usually used to simulate respiration in dystocia or C-sections.

Respiratory Diseases

• Asthma is a chronic inflammatory disease of the lower airways in cats, triggered by inhaled allergens, resulting in smooth muscle contraction.
• Clinical signs include wheezing, dry cough, open-mouth breathing, and dyspnea (labored breathing).
• Treatment includes Glucocorticoids, bronchodilators.
• ROA (Recurrent Airway Obstruction, "heaves" in horses)- treated with medications and management practices, like keeping horses outdoors and managing dust levels.

Hormonal and Reproductive Drugs

• Hormones are chemical messengers produced by glands, regulating cellular activity.
• The main glands include the pituitary, thyroid, parathyroid, adrenal, pancreas, thymus, pineal, and gonads.
• Endocrine glands respond to feedback from the hypothalamus and other endocrine glands. These feedback loops can be negative or positive.
• Exogenous hormones are supplemental or replacement hormone therapy.
• Hormones produced in excess need to be decreased through the use of drugs.
• Example includes using drugs to decrease endogenous hormone production or activity, such as in the case of master gland control via the pituitary gland.

Blood Glucose Regulation

• The pancreas secretes insulin (promotes glucose uptake) and glucagon (increases glucose levels by breaking down glycogen).
• Hypoglycemia is a low blood glucose condition managed to help avoid hypoglycemia, which happens when the body does not produce enough glucose or when the body uses too much glucose.
• Insulin (if administered) is used to decrease glucose levels.
• Drugs can be used to simulate pancreatic beta cell production and increase secretions, thereby stimulating insulin production.
• SGL2 inhibitors prevent glucose reabsorption in the kidneys, enabling urination of excess glucose.
• Examples of hypoglycemic drugs include glipizide, and those drugs are used to treat animal disorders such as diabetes mellitus.

Antidiuretic Hormone (ADH)

• ADH promotes water retention by concentrating urine due to insufficient water release, which is the cause of diabetes insipidus.
• Oxytocin is used as adjunct therapy to stimulate uterine contractions to expel placenta, and stimulate milk letdown.