Drug induced headache, not elsewhere classified

This code represents a headache that is directly caused by the use of a medication, where the headache is not a symptom of another underlying condition. It specifically refers to headaches induced by drugs that are not otherwise classified or specified in more detailed headache codes.

Use this code when documentation clearly links a patient's headache to a prescribed or illicit drug, and no other more specific headache diagnosis applies. This diagnosis is appropriate when the headache resolves or improves with cessation or dosage adjustment of the implicated drug.

• Always sequence this code after the adverse effect or poisoning code for the drug causing the headache, if applicable.
• Ensure documentation specifies the drug involved and the causal link to the headache.
• Differentiate from medication overuse headache (MOH), which has specific diagnostic criteria and a different ICD-9-CM code.