Adverse effect of fentanyl or fentanyl analogs, init

This code signifies an undesirable or harmful reaction experienced by a patient due to the therapeutic use of fentanyl or its synthetic derivatives. This adverse effect occurs during the initial period of treatment for the condition.

Apply this code when a patient presents with symptoms such as respiratory depression, severe nausea, dizziness, or allergic reactions directly attributable to prescribed fentanyl. This is appropriate for the first encounter where the adverse effect is being evaluated and treated.

• Always assign an additional code for the specific manifestation of the adverse effect (e.g., R06.03 for apneic hypoxia).
• Ensure documentation clearly states the fentanyl was administered therapeutically and the reaction was an adverse effect, not poisoning or overdose.
• Verify the encounter is the initial one for this specific adverse reaction to fentanyl. Subsequent encounters would use a different seventh character.