Medication-Overuse Headache
✨Overview
- Also known as: drug-induced headache, analgesic rebound headache, medication-misuse headache
- Classified as a secondary headache disorder (ICHD-3, 2018)
- Occurs when acute headache medications are used ≥15 days/month for >3 months
- Results in transformation of episodic migraine to chronic daily headache
- Reduces prophylaxis efficacy, causes headache rebound as medication wears off
- Most commonly affects patients with migraine or tension-type headache
✨Epidemiology & Risk Factors
- Prevalence: 0.5–2.6%; higher in headache clinics
- Female predominance; peak age: 30–50 years
- ~80% of cases occur in patients with migraine
- Multiple medications often used (90%)
🔹 High-Risk Medications & Overuse Threshold
| Medication Type | Risk Threshold |
|---|---|
| Triptans, ergotamine, opioids, combination analgesics | >10 days/month |
| Paracetamol, NSAIDs, aspirin | >15 days/month |
🔹 Risk Factors (Odds Ratios)
| Category | Factor | OR |
| Demographic | Age <50 | 1.8 |
| Female | 1.9 | |
| Low education | 1.9 | |
| Self-reported | Chronic MSK pain | 1.9 |
| GI complaints | 1.6 | |
| Anxiety/depression | 4.7 | |
| Lifestyle | Smoking | 1.8 |
| Physical inactivity | 2.7 | |
| Metabolic syndrome | 5.3 | |
| High caffeine intake (>540 mg) | 1.4 | |
| Medications | Tranquilizer use | 5.2 |
| Aspirin | 0.5 | |
| Ibuprofen | 0.7 | |
| Opioids | 2.3 |
✨Clinical Features
- Daily headaches: worse early morning (2–5am)
- Headache mimics primary disorder but more frequent and severe
- Easily triggered, often refractory to usual treatments
- Symptoms may include:
- Nausea, vomiting, GI upset
- Fatigue (asthenia), neck pain
- Cognitive dysfunction, irritability
- Autonomic features: tearing, rhinorrhea
- May present to ED requesting opioids
- Withdrawal symptoms (e.g. worsening headache, anxiety) upon cessation
Psychiatric & Behavioral Associations
- High rates of anxiety (58%) and depression (40%)
- Substance-related disorder spectrum: dependency-like behavior (esp. opioids, triptans)
- High risk in patients with family history of MOH or substance use disorders
✨ Diagnosis & Assessment
- Clinical history: type, frequency, duration of medication use
- Confirm medication use pattern against ICHD-3 criteria
- Screening: “How many times in the past year have you used prescription or illegal drugs for non-medical reasons?”
- Sensitivity 100%, specificity 74% for detecting drug use disorder
✨Differential Diagnosis
- Chronic migraine
- Chronic tension-type headache
- Post-traumatic headache
- Secondary headaches: neoplasia, hydrocephalus, infection
✨ Pathophysiology
- Driven by central sensitisation and neuroplasticity in pain pathways
- Chronic exposure leads to reduced receptor sensitivity and medication efficacy
- Genetic variants (e.g. ACE, COMT, BDNF, SERT) may increase vulnerability
✨ Treatment & Management
🔹 Core Strategies
- Patient education: about rebound mechanisms and medication limits
- Start or optimise prophylactic therapy
- Gradual or abrupt withdrawal of overused medication
- Monitor and manage psychiatric comorbidities
🔹 Bridging Therapy
- To reduce withdrawal symptoms during tapering
Options:
- Naproxen MR:
- 750 mg orally daily x 5 days, then 3–4 days/week for 2 weeks → stop
- Prednisolone:
- 50 mg daily x 3 days → taper over 7–10 days then cease
Adjuncts:
- Antiemetics: metoclopramide, promethazine
- Antihistamines: diphenhydramine, hydroxyzine
📉 Prophylaxis Options
- Topiramate: 100–200 mg daily
- Amitriptyline: up to 50 mg daily
✨ Withdrawal Protocol
| Medication | Strategy |
| NSAIDs, paracetamol | Stop abruptly or taper |
| Triptans | Gradual taper (over 5 weeks if needed) |
| Opioids, ergotamines, benzos, barbiturates | Slow taper required |
| Caffeine | Gradual taper |
Post-Withdrawal Maintenance
- Reinstate acute medications with limits:
- Triptans/opioids: <10 days/month
- NSAIDs/paracetamol: <15 days/month
- If noncompliance with triptan limit likely → switch to NSAID
✨ Prevention
- Maximise use of prophylactic medications
- Educate about early and effective use of abortive therapy
- Limit abortive therapy:
- No more than 10 days/month for triptans/opioids
- No more than 15 days/month for simple analgesics
- Prefer long-acting NSAIDs where appropriate
- Behavioural therapy may assist in relapse prevention
✨ Referral Criteria
- Refractory or severe MOH
- Psychiatric overlay or suspected substance use disorder
- Consider inpatient management:
- Lidocaine infusion
- Ketamine infusion
✨ Prognosis
- Withdrawal success in >50% of cases
- Relapse rates: 40–50% at 6 years
- Strongly influenced by patient motivation and access to multidisciplinary care