Medication Overuse Headache

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Medication Overuse Headache

Medication overuse headache (MOH) is the third most common headache disorder and the most common secondary cause of chronic daily headache. It develops when acute headache medications are used too frequently, paradoxically transforming episodic migraine or TTH into a chronic daily pattern. MOH is both preventable and reversible, but its management requires recognizing the problem, withdrawing the overused medication, and establishing effective preventive therapy. Without addressing MOH, no preventive treatment will work optimally.

Bottom Line

Definition: Headache ≥15 days/month in a patient with pre-existing headache, developing as a consequence of regular overuse of acute medication for >3 months
Thresholds: Simple analgesics ≥15 days/month; triptans, ergots, opioids, or combination analgesics ≥10 days/month
Prevalence: ~1-2% of the general population; up to 50% of patients presenting to headache clinics with chronic daily headache
Treatment: Withdrawal of the overused medication is the single most important intervention. Most patients improve within 2-8 weeks of withdrawal.
Bridge therapy during withdrawal: NSAIDs (if not the overused class), steroids, nerve blocks, or anti-emetics
Start preventive therapy simultaneously with withdrawal — reduces relapse rate from ~40% to ~25%
Relapse rate: 25-40% at 1 year. Opioid and barbiturate overuse have the highest relapse rates.

ICHD-3 Criteria

A. Headache occurring on ≥15 days/month in a patient with a pre-existing headache disorder
B. Regular overuse for >3 months of one or more acute treatment drugs:
- Simple analgesics (acetaminophen, NSAIDs): ≥15 days/month
- Triptans: ≥10 days/month
- Ergotamine: ≥10 days/month
- Opioids: ≥10 days/month
- Combination analgesics (with caffeine or barbiturate): ≥10 days/month
- Multiple drug classes (not individually exceeding thresholds): ≥10 days/month combined
C. Not better accounted for by another diagnosis

Medication Class	Threshold	Time to MOH Development	Withdrawal Difficulty
Simple analgesics (acetaminophen, ibuprofen, aspirin)	≥15 days/month	Months to years	Easiest
Triptans	≥10 days/month	~1-2 years	Moderate (1-2 weeks rebound)
Combination analgesics (caffeine-containing)	≥10 days/month	Months	Moderate (caffeine withdrawal adds to symptoms)
Opioids	≥10 days/month	Fastest (weeks-months)	Most difficult (physical dependence, highest relapse rate)
Barbiturates (butalbital)	≥10 days/month	Weeks-months	Most difficult (physical dependence; seizure risk with abrupt withdrawal)
Ergotamine	≥10 days/month	Months	Moderate

Pathophysiology

Central sensitization: Repeated acute medication exposure leads to upregulation of pronociceptive pathways (calcitonin gene-related peptide, substance P, nitric oxide) and downregulation of endogenous antinociceptive systems (serotonergic, endorphin)
Receptor changes: Serotonin receptor (5-HT1B/1D) downregulation with chronic triptan use; opioid receptor tolerance and hyperalgesia with opioid overuse
Cortical excitability: fMRI and PET studies show altered pain processing and reduced descending pain inhibition in MOH patients
Genetic susceptibility: Not all patients who use frequent acute medications develop MOH. Family history of headache and certain behavioral traits (anxiety, catastrophizing) increase risk.
Resolution with withdrawal: Central sensitization reverses within weeks of medication cessation in most patients, supporting the causal role of overuse

Clinical Presentation

How to Recognize MOH

Pattern: Episodic migraine or TTH that gradually transforms into chronic daily headache over months. The headache becomes daily or near-daily, often present upon waking.
Character: Often loses typical migrainous features — becomes a dull, diffuse, bilateral headache with intermittent migrainous exacerbations
Medication pattern: Patient takes acute medication preemptively ("just in case") or at the first hint of headache. Medication use creeps up from episodic to near-daily.
Psychological features: Anxiety about running out of medication, irritability when medication is late, organizing activities around medication availability
Ask every chronic headache patient: "How many days per month do you take something for your headache?" This single question screens for MOH.

Management

Step 1: Withdrawal of Overused Medication

Approach	When to Use	Details
Abrupt withdrawal	Triptans, simple analgesics, ergots, combination analgesics	Stop the overused medication completely on a set date. Expect a withdrawal period of 2-10 days with worsened headache, nausea, anxiety, and sleep disturbance. Most patients improve within 2-4 weeks.
Gradual taper	Opioids and barbiturates (mandatory)	Abrupt withdrawal of opioids causes physical withdrawal syndrome. Barbiturate withdrawal carries seizure risk. Taper over 2-4 weeks with medical supervision.
Outpatient	Most patients	Education, set withdrawal date, provide bridge medications, follow up in 2-4 weeks
Inpatient	Opioid/barbiturate dependence, failed outpatient withdrawal, significant psychiatric comorbidity, high acute medication use (>30 days/month)	Supervised withdrawal with IV bridge therapy (DHE protocol, ketorolac, magnesium)

Step 2: Bridge Therapy During Withdrawal

Naproxen 500 mg BID scheduled (not PRN) for 2-3 weeks — if NSAIDs were not the overused class. Most commonly used bridge.
Prednisone taper: 60 mg × 5 days then taper over 2 weeks. Evidence is mixed (some RCTs positive, some negative) but widely used.
GON block: Bupivacaine +/- steroid at withdrawal onset. Provides 2-4 weeks of reduced headache without medication.
Anti-emetics: Metoclopramide 10 mg or prochlorperazine 10 mg PRN for nausea during withdrawal.
IV DHE protocol (inpatient): Repetitive IV DHE over 3-5 days. Highly effective for breaking the MOH cycle but requires admission or infusion center.

Step 3: Start Preventive Therapy

Preventive Therapy and MOH

Start a preventive simultaneously with withdrawal — this is now the recommended approach (previously, some advocated withdrawing first and starting a preventive later)
Any evidence-based migraine preventive can be used: topiramate, amitriptyline, beta-blocker, CGRP mAb, Botox (if chronic migraine criteria met)
Topiramate has the best evidence in the context of MOH specifically — two positive RCTs showing benefit even without formal withdrawal (medication overuse may partly reverse as headache frequency decreases)
OnabotulinumtoxinA: PREEMPT included patients with medication overuse. Botox is effective in chronic migraine with MOH without requiring formal withdrawal first.
CGRP mAbs: Post-hoc analyses of major trials (HALO-CM, FOCUS) show efficacy in chronic migraine patients with MOH, with concurrent reduction in acute medication use
Key point: Preventive medications are less effective if overuse continues. Withdrawal amplifies the benefit of prevention.

Step 4: Education and Relapse Prevention

Limit acute medication to <10 days/month (triptans, combination analgesics) or <15 days/month (simple analgesics) going forward
Headache diary: Track both headache days and medication days. This is the single best tool for early detection of relapse.
Structured follow-up: Monthly for the first 3-6 months after withdrawal. Relapse is most common in the first 6 months.
Identify and address drivers: Anxiety, untreated depression, inadequate preventive therapy, and lack of alternative acute options all predispose to relapse

Prognosis

Overused Medication	Withdrawal Duration	1-Year Relapse Rate
Triptans	~4 days (shortest)	~20-25%
Simple analgesics	~7 days	~25-30%
Combination analgesics	~7-10 days	~30%
Opioids	~10-14 days	~40-50% (worst prognosis)
Barbiturates	~10-14 days	~40-50%

References

Diener HC, et al. Pathophysiology, prevention, and treatment of medication overuse headache. Lancet Neurol. 2019;18(9):891-902.
Munksgaard SB, et al. Withdrawn: medication-overuse headache. Cochrane Database Syst Rev. 2019.
Silberstein SD, et al. OnabotulinumtoxinA for treatment of chronic migraine: subgroup analysis of patients with medication overuse from the PREEMPT trials. J Headache Pain. 2013;14:86.
Diener HC, et al. Topiramate reduces headache days in chronic migraine: a randomized, double-blind, placebo-controlled study. Cephalalgia. 2007;27(7):814-823.
Headache Classification Committee of the International Headache Society. The International Classification of Headache Disorders, 3rd edition. Cephalalgia. 2018;38(1):1-211.