Adverse effect of antiallergic and antiemetic drugs, init

This code signifies an undesirable or harmful reaction experienced by a patient due to the therapeutic use of medications intended to treat allergies or prevent/alleviate nausea and vomiting. These adverse effects occur despite the drug being correctly prescribed and administered.

Apply this code when documenting a patient's initial presentation for symptoms resulting from an adverse reaction to antihistamines, decongestants, or antiemetic agents. This includes reactions like severe drowsiness, paradoxical excitation, cardiac arrhythmias, or extrapyramidal symptoms, when the drug was taken as directed.

• Always sequence this code first if it is the primary reason for the encounter.
• Requires an additional code to identify the specific adverse effect or manifestation.
• Ensure documentation clearly states the drug was taken correctly and the reaction was unexpected.