Drug-induced headache.

Medication overuse headache is a common complex disorder with physical and psychologic elements. Treatment may be difficult but often is accomplished in an outpatient setting. Some patients require inpatient treatments. An option for some is day treatment with i.v medication in an infusion center over several consecutive days. The two most common classes of drugs that acutely induce headache are NO donors, typified by NTG, and PDE inhibitors, typified by sildenafil. NO donors cause a biphasic headache in migraineurs and PDE inhibitors a monophasic one.