724 Repetitive Intravenous Prochlorperazine Treatment of Patients With Refractory Chronic Daily Headache Shiang-Ru Lu, MD; Jong-Ling Fuh, MD; Kai-Dih Juang, MD; Shuu-Jiun Wang, MD Objectives.—To investigate the efficacy and long-term outcome of intravenous prochlorperazine for the treatment of refractory chronic daily headache. Background.—Unlike dihydroergotamine, the treatment results of intravenous neuroleptics as first-line agents for refractory chronic daily headache have rarely been reported. Methods.—We retrospectively analyzed the data of inpatients with refractory chronic daily headache who re- ceived intravenous repetitive prochlorperazine treatment from November 1996 to March 1999. A semistructured telephone follow-up interview was done in September 1999. Results.—A total of 135 patients (44 men, 91 women) were recruited, including 95 (70%) with analgesic over- use. After intravenous prochlorperazine treatment, 121 (90%) achieved a 50% or greater reduction of headache intensity, including 85 (63%) who became headache-free. The mean hospital stay was 6.2  2.7 days, and mean to- tal prochlorperazine used was 98  48 mg. Acute extrapyramidal symptoms occurred in 21 patients (16%). One hundred twenty-four patients (92%) were successfully followed up, with a mean duration of 14.3  7.5 months. Compared with pretreatment status, 93 patients (75%) considered their headache intensity decreased, and 86 pa- tients (69%) considered their headache frequency decreased, although 40 (32%) still had a daily headache. Of the 87 patients with analgesic overuse who could be followed, 61 (70%) no longer overused analgesics. Poor response to prochlorperazine treatment (relative risk, 1.8) and presence of major depression (relative risk, 1.8) were predic- tors of persistent chronic daily headache at follow-up. Conclusions.—Prochlorperazine was effective and safe in the treatment of patients with refractory chronic daily headache with or without analgesic overuse. Compared with dihydroergotamine, prochlorperazine seemed less effective at achieving “freedom from headache” during hospitalization, but had a similar outcome at follow-up. Key words: chronic daily headache, migraine, prochlorperazine, tension-type headache Abbreviations: CDH chronic daily headache, TM transformed migraine, CTTH chronic tension-type headache, NDPH new daily persistent headache, DHE dihydroergotamine, EPS extrapyramidal symptoms (Headache 2000;40:724-729) Chronic daily headache (CDH) refers to daily or near-daily headache with a duration of more than 4 hours per day and a frequency of more than 15 days per month for more than 1 month if untreated. 1 It is classified into four subtypes: transformed migraine (TM), chronic tension-type headache (CTTH), new daily persistent headache (NDPH), and hemicrania continua (HC). Overuse of and dependence on anal- gesics or ergotamine have been proposed as an im- portant factor in the development of CDH, especially in TM. 2,3 Abrupt discontinuation of these drugs 4,5 (detoxification) usually results in headache improve- ment but frequently causes discomfort. Intravenous (IV) dihydroergotamine (DHE) (Raskin protocol) 6 has been shown to shorten the hospital stay and re- duce the analgesic withdrawal symptoms. 6,7 There- fore, it is the treatment of choice for detoxification. From the Neurological Institute, Taipei Veterans General Hospital and Departments of Neurology (Drs. Lu, Fuh, Wang) and Psychiatry (Dr. Juang), National Yang-Ming University School of Medicine, Taipei, Taiwan. Address all correspondence to Dr. Shuu-Jiun Wang, The Neu- rological Institute, Taipei Veterans General Hospital, 11217, Taipei, Taiwan. Accepted for publication June 6, 2000.