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| This news site is not sanctioned by, nor part of, the Diamond Headache Foundation, The American Academy of Neurology OR The American Headache Society. |
| News covering selected sessions related to migraine from 2008 medical conferences. |
| Annual Meeting of the American Academy of Neurology |
Chicago, IL April 15-18, 2008 |
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Medication Overuse Headache: New Insights
into an Old Problem |
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BY DON SCHRADER
Contributing Writer |
CHICAGO
(ECCC)— Headache caused by medication use continues
to challenge and frustrate clinicians almost 60 years after the
condition was first described, Dr. Hans-Christoph Diener said
April 18 during the annual meeting of the American Academy of
Neurology.
As described by Peters and Horton in 1951, medication-overuse
headache had several universal features: Patients required
increasingly higher doses of headache medication. Headache
became more frequent and severe, and eventually affected
patients had headache every day. When patients stopped their
headache medication altogether, the headache pain initially
worsened before improving (Proc Staff Meet Mayo Clinic.
1951;26:153-161).
“The patients have a terrible time for a few days after they
stop treatment but then they start to feel better,” said Dr.
Diener, chair of neurology at the University of Duisburg-Essen
in Germany.
The 1988 International Headache Classification system defined
drug-induced headache as a chronic headache that occurs at least
15 days a month and is associated with use of headache
medications for at least 10 to 15 days a month for 3 or more
months. The headache improves after medication withdrawal. The
International Headache Society affirmed the criteria in the 2004
headache classification system.
The criteria for medication-overuse headache were further
refined in 2006 to describe the condition’s association with
different types of headache medications. Additionally, a new
criterion was added: The headache developed or markedly worsened
during medication overuse (Cephalalgia. 2006;26:1409-1410).
“This meant that you no longer had to wait until medication
withdrawal to make the diagnosis,” said Dr. Diener.
The estimated prevalence of medication-overuse headache has
ranged from 1% to 3% of the general population, to 10% in
published clinical series, to 25% in headache specialty centers.
In a review of published studies involving a total of 2,600
patients, Dr. Diener and colleagues found that
medication-overuse headache has a female-male predominance of
3.5:1 and that two thirds of the patients initially had
migraine. Age at onset was about 40 years, a duration of primary
headache of about 20 years, a duration of drug overuse of 10
years, and a duration of medication-overuse headache of about 6
years (In: The headaches. 2nd ed. 1999:871-878).
Dr. Diener and his colleagues also found that medication-overuse
headache has characteristics specific to the medication that is
being over used (Neurology. 2002;59:1011-1014).
“Patients are amazed that I can tell them what drug they are
using before they tell me,” said Dr. Diener.
Not all headache patients with the same medication dosage
develop drug-overuse headache. Population-based studies suggest
a chronification (transition from episodic to chronic headache)
incidence of 3%. The incidence in headache specialty centers
might be as much as fivefold greater.
In an ongoing study that eventually will include 30,000 patients
followed for 5 years, the German Headache Consortium has
identified several factors that significantly increase the risk
of chronification: drug intake more than 10 days a month,
chronic facial pain, chronic back pain, and use of two or more
headache drugs.
Depression and anxiety also increase susceptibility to
medication-overuse headache. Headache patients with comorbid
anxiety or depression have a sixfold greater risk of
medication-overuse headache compared with patients who do not
have either of those conditions, said Dr. Diener.
The pathophysiologic mechanisms of medication overuse headache
remain undetermined but most likely involve central
sensitization, said Dr. Diener. Other possibilities include
dysregulation of 5-HT metabolism, downregulation of 5-HT
receptors in the trigeminal, and sensitization of peripheral
nociceptors.
Effective treatment of medication-overuse headache includes
patient education, identification of risk factors, and drug
withdrawal. Long-term management focuses on preventive treatment
and psychological support.
“This is a condition that requires collaboration among the
neurologist, the behavioral psychologist, and the physical
therapist,” said Dr. Diener. “If you try to treat patients on
your own, you are asking for failure.”
In about 90% of cases, medication withdrawal can be accomplished
on an outpatient basis. Patients who use bartiburates, opioids,
tranquilizers, or multiple drugs will likely require inpatient
care, as will patients with severe anxiety, depression, or other
psychiatric disorders.
Without regular follow-up, the risk of relapse is substantial,
said Dr. Diener. The risk of relapse is greater with
tension-type and mixed headache compared with pure migraine.
Analgesics have a much higher association with relapse than do
ergots and triptans. The relapse rate for patients treated with
opioids is virtually 100%.
“We teach doctors not to treat migraine patients with opioids,
particularly patients who have frequent headache attacks,” said
Dr. Diener. |
| Copyright 2008 Elsevier Custom Conference Coverage. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyright owner. No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products liability, through negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Because of rapid advances in the medical sciences, the Publisher recommends that independent verification of diagnoses and drug dosages should be made. Opinions expressed in this publication are those of the original authors and do not necessarily reflect those of the Publisher, the sponsor, or the editors. Elsevier assumes no liability for any material published herein. |
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