Underdosing of drug/meds/biol subst, sequela

This code signifies a long-term or residual effect resulting from a patient receiving an insufficient amount of a drug, medicament, or biological substance. This underdosing led to a persistent health problem or complication that is now being addressed. The original underdosing event is in the past, and the current encounter focuses on managing its lasting consequences.

Use this code when documenting a patient's current condition that is a direct sequela of a previously identified underdosing of a medication or biological. This applies when the patient is no longer experiencing the acute underdosing event itself, but rather its chronic or delayed effects. Examples include organ damage from prolonged insufficient medication, or a chronic infection due to inadequate prophylactic treatment.

• Always sequence the code for the specific sequela (e.g., chronic kidney disease, recurrent infection) first, followed by this sequela code.
• Ensure documentation clearly links the current condition to a past underdosing event.
• This code is for the sequela of underdosing, not the acute underdosing event itself (which would use the 'A' or 'D' seventh character).