Adverse effect of antiviral drugs, subsequent encounter

This code signifies a harmful or undesirable reaction experienced by a patient due to the therapeutic use of an antiviral medication, specifically when the patient is receiving routine care during the healing or recovery phase of the adverse effect. It indicates that the initial injury or complication from the drug has already occurred, and the current encounter is for ongoing management.

Apply this code when documenting follow-up visits for patients experiencing persistent side effects or complications from antiviral drugs, such as ongoing liver enzyme elevation, renal dysfunction, or dermatological reactions. It is appropriate for encounters where the focus is on monitoring the resolution of the adverse effect or managing its long-term sequelae after the initial acute phase.

• Always use in conjunction with a code identifying the specific adverse effect (e.g., R94.5 for abnormal liver function studies).
• Ensure the documentation clearly states the adverse effect is due to an antiviral drug and that this is a subsequent encounter.
• Distinguish from initial encounters (A) or sequela encounters (S) based on the stage of care for the adverse effect.