Evaluation of lithium response in episodic cluster headache: a retrospective case series.
OBJECTIVE
In this study, we attempted to evaluate the response to lithium treatment and its tolerability in the prevention of episodic cluster headache (CH) and to identify clinical predictors of response.


BACKGROUND
Verapamil and lithium are the most widely used drugs in the prevention of CH attacks. Lithium is considered a second-line treatment in part because of its potentially severe adverse drug reactions (ADRs). Evidence for the efficacy of lithium in CH prevention is greater in chronic than in episodic patients. In addition, because of its narrow therapeutic window and ADRs (which can be significantly reduced with proper periodical monitoring of blood levels), lithium is recommended only in chronic CH, when other drugs are ineffective or potentially harmful.


METHODS
Our primary aim was to determine whether lithium reduced the number of attacks per day (attack frequency). We compared attack frequency in 3 periods: run-in, the first, and the second week of lithium treatment. Responders were defined as patients showing at least a 50% reduction in attack frequency.


RESULTS
Lithium response was evaluated in 26 patients. Treatment led to a significant reduction in attack frequency within 2 weeks in a percentage of 77% of responders and 23% of nonresponders. Responders and nonresponders did not differ in terms of demographic and clinical characteristics. Only 15% of patients experienced mild ADRs.


CONCLUSIONS
Our study provides additional evidence on the effectiveness of lithium in the prevention of episodic CH. It also shows the tolerability of lithium, given the short duration of treatment and low dosage.
Headache Center, Unit of Clinical Pharmacology, University-Hospital Agency of Cagliari, Cagliari, Italy. mimmastoc@hotmail.it
Maria Erminia
ME
Stochino
Arianna
A
Deidda
Carlo
C
Asuni
Alessandra
A
Cherchi
Mirko
M
Manchia
Maria
M
Del Zompo
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D003027:Cluster Headache / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008094:Lithium / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D008094:Lithium