Question 86

Therapeutic duplication is a concern for a patient presenting prescriptions for both verapamil and nifedipine.

Both verapamil and nifedipine are calcium channel blockers used to treat hypertension and angina. Prescribing both medications can lead to therapeutic duplication, increasing the risk of adverse effects without providing additional therapeutic benefit.

A) Drug-disease contraindication

This option is incorrect as a drug-disease contraindication refers to a situation where a medication is inappropriate due to a specific health condition the patient has. While there may be individual considerations, the primary concern here is the overlap in medication classes rather than a contraindication related to a specific disease.

B) Narrow therapeutic index

This option is also incorrect. A narrow therapeutic index refers to medications for which the effective dose is close to the toxic dose, requiring careful monitoring. While both verapamil and nifedipine should be used cautiously, they do not inherently share a narrow therapeutic index concern when used together.

C) Duration of therapy

This choice is not relevant to the question at hand. Duration of therapy refers to how long a medication should be prescribed, which is not the primary concern with these two medications being prescribed together. The issue is more about the overlap in their therapeutic effects rather than the length of time each should be used.

D) Therapeutic duplication

This is the correct answer as both verapamil and nifedipine serve similar purposes in managing cardiovascular conditions. Prescribing both can lead to an unnecessary increase in calcium channel blockade, potentially causing excessive hypotension, bradycardia, or other adverse effects.

Conclusion

Therapeutic duplication is a significant concern when a patient is prescribed both verapamil and nifedipine, as they belong to the same class of medications and can lead to compounded effects without additional therapeutic benefits. Other options, such as drug-disease contraindications or narrow therapeutic indices, do not adequately address the primary issue of overlapping drug effects in this scenario. Thus, it is essential to recognize and manage the risks associated with therapeutic duplication in patients on multiple medications.