Underdosing of peripheral vasodilators, subsequent encounter

This code indicates that a patient is experiencing adverse effects or complications due to receiving an insufficient amount of a peripheral vasodilator during a subsequent encounter. Peripheral vasodilators are medications used to widen blood vessels, often to improve blood flow to the extremities. Underdosing can lead to worsening symptoms of the underlying condition, such as peripheral artery disease, or a lack of therapeutic effect.

Use this code when a patient presents for follow-up care related to the ongoing management of a condition, and it is determined that their peripheral vasodilator medication was administered at a dose lower than prescribed or therapeutically effective. This applies when the underdosing is the cause of the current clinical presentation or a contributing factor to the patient's symptoms.

• Requires an additional code to specify the manifestation of the underdosing (e.g., worsening claudication).
• The 7th character "D" signifies a subsequent encounter, meaning the patient is receiving routine care during the healing or recovery phase.
• Distinguish from poisoning (T46.7X1-) or adverse effect (T46.7X5-) which imply incorrect administration or an unexpected reaction at a correct dose, respectively.