Underdosing of penicillins, initial encounter

This code signifies that a patient has received an insufficient dose of a penicillin-based antibiotic, leading to a suboptimal therapeutic effect or treatment failure. This underdosing can result from various factors, including patient non-adherence, incorrect prescription, or issues with medication administration.

Apply this code when documenting the initial presentation or diagnosis of a patient experiencing adverse effects or treatment failure directly attributable to receiving less than the prescribed or therapeutically effective amount of penicillin. This is relevant when the underdosing is the primary reason for the current encounter.

• Always assign a secondary code for the specific medical condition being treated with the penicillin.
• Distinguish carefully between underdosing (patient received too little) and non-compliance (patient did not take medication as prescribed).
• Ensure documentation clearly supports that the underdosing occurred during the "initial encounter" for this specific issue.