Unsp adverse effect of drug or medicament, init encntr

This code signifies an undesirable or harmful reaction to a drug or medication when the specific nature of that reaction is not documented. It's used when a patient experiences an adverse event from a therapeutic substance, but the precise manifestation of the effect is unknown or unrecorded.

This code is appropriate for initial encounters where a patient presents with symptoms attributed to a drug, but the physician's documentation only states "adverse effect of drug" without further detail (e.g., rash, nausea, anaphylaxis). It's also used when the specific drug causing the reaction is known, but the type of adverse effect is not.

• Always strive for a more specific adverse effect code if documentation permits.
• This code is for the initial encounter for the adverse effect; subsequent encounters would use the appropriate seventh character.
• Do not use this code for poisoning, underdosing, or allergic reactions where the specific allergic manifestation is known.