Underdosing of calcium-channel blockers, initial encounter

This code signifies that a patient has received less than the prescribed or recommended dose of a calcium-channel blocker, leading to a suboptimal therapeutic effect. This underdosing is occurring during the initial period of treatment or assessment for the underdosing event.

Use this code when a patient's medical record indicates that their calcium-channel blocker medication was administered at a lower dose than intended, contributing to uncontrolled hypertension, angina, or other conditions managed by these drugs. This applies when the underdosing is first identified or being actively managed.

• Always ensure documentation clearly specifies "underdosing" and identifies the drug class as a calcium-channel blocker.
• The "A" seventh character indicates an initial encounter, meaning the patient is receiving active treatment for the underdosing.
• Do not use this code for medication non-compliance where the patient intentionally or unintentionally did not take the medication as prescribed; this code is for situations where the administered dose was insufficient.