Medication Overuse Headache
Summary
Medication Overuse Headache (MOH) is a chronic daily headache caused by regular, excessive use of acute headache medications. It is one of the most common causes of chronic headache, often developing in patients with an underlying primary headache disorder (migraine or tension-type headache). The diagnostic criteria require headache on ≥15 days/month with regular overuse of acute headache medications for >3 months. The key to management is withdrawal of the offending medication, which initially worsens headache but leads to significant improvement after 2-8 weeks. Prevention of relapse through headache prophylaxis and patient education is essential.
Key Facts
- Definition: Headache ≥15 days/month + medication overuse >3 months
- Thresholds: Triptans/Opiates/Combination >10 days/month; Simple analgesics >15 days/month
- Underlying Condition: Usually migraine or tension-type headache
- Treatment: Withdrawal of offending medication
- Course: Headache worsens for 2-4 weeks then improves
- Prevention: Prophylactic treatment; Limit acute medication use
Clinical Pearls
"10-15 Day Rule": Using triptans, opioids, or combination analgesics on ≥10 days/month, or simple analgesics on ≥15 days/month, risks MOH.
"It Gets Worse Before Better": Withdrawal causes transient worsening of headache (2-4 weeks), followed by significant improvement. Prepare the patient.
"Codeine is the Enemy": Opiates and codeine-containing medications are most likely to cause MOH and have the worst withdrawal. Avoid in headache management.
"Address the Underlying Headache": After withdrawal, start prophylaxis for the underlying primary headache to prevent relapse.
Prevalence
- 1-2% of general population
- 50% of patients attending headache clinics
- Common cause of chronic daily headache
Demographics
- F:M = 3-4:1
- Peak: 40-50 years
- Usually has underlying migraine or TTH
Risk Factors
| Factor | Notes |
|---|---|
| Frequent primary headaches | Migraine, TTH |
| Anxiety/Depression | Common comorbidities |
| Opioid/Codeine use | Highest risk |
| Low socioeconomic status | |
| Obesity |
Mechanism
- Complex and not fully understood
- Central sensitisation
- Downregulation of pain-modulating systems
- Neuroplastic changes in brainstem
The Cycle
- Primary headache (e.g., migraine)
- Take acute medication (relief)
- More frequent use (escalation)
- Tolerance/Adaptation (need more)
- Rebound headache when medication wears off
- Daily or near-daily headache
- Cycle repeats
Typical History
Headache Features
Neurological Examination
- Usually normal
- Any focal signs or papilloedema → Investigate for secondary cause
"Red Flags" to Exclude Secondary Cause
- New headache type
- Age >50
- Systemic symptoms
- Neurological signs
- Papilloedema
- Positional headache
Usually Not Required
- Diagnosis is clinical based on history
When to Investigate
| Indication | Investigation |
|---|---|
| New headache type or red flags | MRI Brain |
| Papilloedema | MRI + MRV; LP |
| Systemic symptoms | ESR, CRP (GCA if older) |
Management Approach
┌──────────────────────────────────────────────────────────┐
│ MEDICATION OVERUSE HEADACHE MANAGEMENT │
├──────────────────────────────────────────────────────────┤
│ │
│ STEP 1: PATIENT EDUCATION │
│ • Explain the diagnosis clearly │
│ • "Medication is now causing headache, not curing it" │
│ • Prepare for worsening before improvement │
│ │
│ STEP 2: WITHDRAWAL OF OVERUSED MEDICATION │
│ • Abrupt withdrawal (usually recommended) │
│ • Headache will worsen for 2-4 weeks, then improve │
│ • Symptoms: Headache, nausea, anxiety, sleep problems │
│ │
│ STEP 3: BRIDGE THERAPY (Optional) │
│ • Naproxen 500mg BD for 2-4 weeks │
│ • Antiemetics PRN │
│ • Avoid opiates and barbiturates │
│ │
│ STEP 4: PROPHYLAXIS FOR UNDERLYING HEADACHE │
│ • Start after withdrawal (or concurrently) │
│ • Migraine: Propranolol, Amitriptyline, Topiramate │
│ • TTH: Amitriptyline │
│ • Reduces relapse risk │
│ │
│ STEP 5: LIMIT FUTURE ACUTE MEDICATION USE │
│ • Triptans/Opioids: Max 10 days/month │
│ • Simple analgesics: Max 15 days/month │
│ • Avoid codeine and opioids in headache │
│ • Headache diary │
│ │
│ FOLLOW-UP: │
│ • Review at 4-6 weeks │
│ • Most improve significantly by 8-12 weeks │
│ • Long-term relapse rate: 20-40% │
│ │
└──────────────────────────────────────────────────────────┘
Of MOH
- Chronic daily headache
- Reduced quality of life
- Drug dependence (especially opioids)
- Depression and anxiety
- Lost work days
Of Withdrawal
- Transient worsening of headache
- Nausea, vomiting
- Anxiety, insomnia
- Rare: Seizures (if barbiturate-containing medications)
With Withdrawal
- 50-70% improve significantly
- Improvement starts 2-4 weeks after withdrawal
- Best response by 8-12 weeks
Risk of Relapse
- 20-40% relapse within 1 year
- Higher if underlying headache not controlled
- Patient education reduces relapse
Key Guidelines
- NICE CKS: Medication Overuse Headache
- IHS (ICHD-3): Diagnostic Criteria
- European Headache Federation Guidelines
Key Evidence
Withdrawal
- Abrupt withdrawal as effective as gradual
- Adding prophylaxis improves outcomes
What is Medication Overuse Headache?
Medication overuse headache (sometimes called "rebound headache") happens when you take painkillers or headache medicines too often. Ironically, the very medicines you take for headaches can start to cause them.
How Does It Happen?
If you take headache medicines on too many days per month (more than 10-15 days), your brain can become dependent on them. When the medicine wears off, you get a rebound headache, which makes you take more medicine, and a cycle develops.
What Are the Symptoms?
- Headaches most days (or every day)
- Need to take painkillers frequently
- Headache is present when you wake up
- Medicines work less well than they used to
How is It Treated?
The main treatment is to stop the overused medication. This is difficult because your headaches will get worse for the first 2-4 weeks. But after that, they will significantly improve.
Your doctor may also give you:
- A "bridge" medicine (like naproxen) for a short time
- A preventative medicine to reduce future headaches
How Can I Prevent It Coming Back?
- Limit headache medicines to no more than 10-15 days per month
- Avoid codeine and opioid painkillers for headaches
- Keep a headache diary
- Take preventative treatment if you have frequent headaches
Primary Guidelines
- NICE Clinical Knowledge Summaries. Medication Overuse Headache. cks.nice.org.uk
Key Studies
- Diener HC, et al. Medication-overuse headache: risk factors, pathophysiology and management. Nat Rev Neurol. 2016;12(10):575-583. PMID: 27609318