A nurse is reviewing the concept of therapeutic index for medications. Which of the following statements best describes a drug with a narrow therapeutic index?

A. "The IV heparin increases the effects of the warfarin and decreases the length of your hospital stay.": Heparin does not enhance the effect of warfarin directly. Their mechanisms of action are different, and warfarin’s effect is delayed. Heparin is used to maintain anticoagulation until warfarin becomes effective.
B. "Both heparin and warfarin work together to dissolve the clots.": Neither heparin nor warfarin dissolves existing clots; they prevent further clot formation and allow the body’s natural fibrinolytic system to break down clots. This statement misrepresents their action.
C. "Warfarin takes several days to work, so the IV heparin will be used until the warfarin reaches a therapeutic level.": Warfarin requires 3–5 days to reach therapeutic INR levels due to its action on vitamin K-dependent clotting factors. Heparin provides immediate anticoagulation, which is why it is continued until warfarin is therapeutic.
D. "I will call the provider to get a prescription for discontinuing the IV heparin today.": Discontinuing heparin too soon places the patient at risk for clot progression or embolization, as warfarin will not yet be therapeutic. The nurse should understand and educate the patient about the rationale for overlap.

A. Montelukast: This leukotriene receptor antagonist is used for long-term asthma control and prevention of exercise-induced bronchospasm. It is not effective for treating acute asthma attacks due to its delayed onset of action.
B. Salmeterol: This is a long-acting beta-2 agonist (LABA) used for maintenance therapy in asthma. It has a slower onset and should never be used for rapid symptom relief during an acute attack, as doing so can delay appropriate treatment.
C. Albuterol: Albuterol is a short-acting beta-2 agonist (SABA) that provides rapid bronchodilation and is the first-line rescue medication for aborting an acute asthma attack. It works within minutes to relieve bronchospasm and improve airflow.
D. Beclomethasone: This inhaled corticosteroid is used for long-term asthma management by reducing airway inflammation. It is not effective in acute situations because it does not provide immediate bronchodilation.