Question

A man with obstructive pulmonary disease requires therapy to prevent anginal attacks. Which drug should be avoided in this patient? (A) verapamil (B) felodipine (C) isosorbide mononitrate (D) diltiazem (E) propranolol

Short answer

Propranolol (E) should be avoided.

Step-by-step solution

Understanding the Medical Context

In this exercise, the patient suffers from obstructive pulmonary disease and is at risk of anginal attacks. We need to determine which drug is not suitable due to their condition. Obstructive pulmonary disease patients are usually advised to avoid certain medications that might worsen their respiratory status.

Identifying Problematic Drug Classes

Patients with obstructive pulmonary disease should avoid non-selective beta-blockers because they can exacerbate breathing difficulties by blocking beta-2 adrenergic receptors in the lungs. This leads us to focus on the listed options that belong to this class of drugs.

Reviewing Each Option

Let's review each option: (A) Verapamil and (B) Felodipine are calcium channel blockers, (C) Isosorbide mononitrate is a nitrate, (D) Diltiazem is a non-dihydropyridine calcium channel blocker, (E) Propranolol is a non-selective beta-blocker.

Identifying the Drug That Should Be Avoided

Propranolol (E) is a non-selective beta-blocker and therefore can worsen symptoms in patients with obstructive pulmonary disease due to its potential to cause bronchoconstriction.

Conclusion and Correct Choice

Based on the analysis, propranolol should be avoided in a patient with obstructive pulmonary disease as it can worsen the respiratory condition.

Key concepts

Obstructive Pulmonary Disease Overview

Obstructive pulmonary disease refers to a category of conditions that block airflow and cause breathing-related problems. The most common forms are chronic obstructive pulmonary disease (COPD) and asthma. These conditions cause the airways to narrow, leading to symptoms like shortness of breath, coughing, and wheezing.
Patients with obstructive pulmonary disease must be cautious with certain medications, as some can exacerbate breathing difficulties. Non-selective beta-blockers, for example, can trigger bronchoconstriction by blocking beta-2 adrenergic receptors in the lungs. This can lead to worsening of symptoms, making it crucial to avoid these drugs unless absolutely necessary. Understanding these interactions is vital for managing the disease effectively.

Angina Management in Patients

Angina is a condition characterized by chest pain due to reduced blood flow to the heart muscles. It is often described as a squeezing or pressing pain in the chest. Proper management of angina involves lifestyle changes, medication, and sometimes medical procedures.
For patients with obstructive pulmonary disease, angina management must consider their respiratory condition to avoid complications. Medications used to treat angina include:

• Calcium channel blockers
• Nitrates
• Aspirin and antiplatelet agents

Each of these medications has a specific role in improving blood flow and reducing heart strain, but choosing the right drug is essential for safe management.

Beta-Blockers and Respiratory Considerations

Beta-blockers are medications that reduce heart rate, blood pressure, and overall heart workload. They are used in treating various heart conditions, such as hypertension, arrhythmias, and angina. However, not all beta-blockers are suitable for everyone, especially for patients with obstructive pulmonary disease.
Non-selective beta-blockers, like propranolol, are particularly risky as they affect both beta-1 and beta-2 receptors. The beta-2 receptors influence lung function, and blocking them can cause bronchoconstriction, leading to breathing issues. For patients with obstructive pulmonary disease, selective beta-blockers, which mainly target beta-1 receptors, are safer alternatives if beta-blocker therapy is necessary.

Calcium Channel Blockers as an Option

Calcium channel blockers are a class of drugs that relax the muscles of your heart and blood vessels. They are often used in the treatment of high blood pressure, certain arrhythmias, and angina. These medications help improve blood flow to the heart by relaxing the muscle around blood vessels, thus reducing the heart's workload.
There are two main types of calcium channel blockers: dihydropyridines and non-dihydropyridines. Both types can benefit patients with angina, but they have different effects and side profiles. For instance, verapamil and diltiazem (non-dihydropyridines) are known for their effect on heart rate, while dihydropyridines like felodipine primarily affect vascular tone.

Nitrate Therapy in Angina Relief

Nitrate therapy is a staple in the treatment of angina. Nitrates help dilate the blood vessels, easing the heart's workload and improving blood delivery to the heart muscle. The vasodilation helps reduce chest pain by lowering the oxygen demand of the heart.
Isosorbide mononitrate is a common nitrate used to prevent angina attacks. It is typically used in patients who need long-term management for their chest pain. Nitrate therapy is generally considered safe for patients with obstructive pulmonary disease, as it doesn't interfere with lung function, making it a preferred option for managing angina in these individuals.