Pregabalin 75 mg + Nortriptyline 10 mg Combination Tablet
Primary Indication
This fixed-dose combination is indicated for the treatment of neuropathic pain, particularly diabetic peripheral neuropathy (DPN), where both agents work synergistically to provide superior pain relief compared to monotherapy. 1, 2
The combination leverages pregabalin's calcium channel modulation with nortriptyline's norepinephrine and serotonin reuptake inhibition to target different pain pathways simultaneously.
Dosing Recommendations
Starting Dose
- Pregabalin 75 mg + Nortriptyline 10 mg once daily at bedtime 1, 3
- The low nortriptyline dose (10 mg) minimizes anticholinergic side effects while providing analgesic benefit
Titration Schedule
- Week 1-2: Continue 75 mg/10 mg once daily
- Week 3 onwards: May increase pregabalin to 150 mg daily (75 mg twice daily) while maintaining nortriptyline 10-25 mg at bedtime 1
- Maximum doses: Pregabalin up to 300-600 mg/day in divided doses; nortriptyline up to 50-150 mg/day 1, 3
Special Populations
- Elderly patients: Start with the lowest dose and titrate more slowly due to increased risk of falls, confusion, and anticholinergic effects 4, 3
- Renal impairment: Reduce pregabalin dose based on creatinine clearance; nortriptyline requires no adjustment 1
- Hepatic impairment: Use nortriptyline with caution
Duration of Adequate Trial
- 6-8 weeks minimum, with at least 2 weeks at maximum tolerated dose before declaring treatment failure 3
Contraindications
Absolute Contraindications (Nortriptyline)
- Concurrent use with MAO inhibitors (must discontinue MAO inhibitor at least 2 weeks before starting) 5
- Acute recovery period after myocardial infarction 5
- Known hypersensitivity to nortriptyline or dibenzazepines 5
Relative Contraindications/Cautions
- Pregabalin: History of angioedema, severe respiratory impairment, substance abuse history 6
- Nortriptyline: Cardiac conduction abnormalities, prolonged QTc interval, urinary retention, narrow-angle glaucoma 7, 3
- Both: Avoid in patients with severe cardiac disease without ECG monitoring 7
Drug Interactions
Major Interactions
CNS Depressants (Critical Warning)
- Opioids + this combination = severe respiratory depression risk 6
- Benzodiazepines, alcohol, and other sedatives cause additive somnolence and dizziness 6
- Avoid concurrent use when possible; if necessary, use lowest effective doses and monitor closely
MAO Inhibitors
- Absolutely contraindicated with nortriptyline - can cause hyperpyretic crises, severe convulsions, and death 5
- Must wait 2 weeks after stopping MAO inhibitor before starting nortriptyline
Thiazolidinediones (Diabetes Medications)
- Additive edema and weight gain with pregabalin 6
- May precipitate heart failure in susceptible patients
Anticholinergic Medications
- Additive anticholinergic effects with nortriptyline (dry mouth, urinary retention, constipation, confusion) 1, 7
Monitoring Required
- Cardiac monitoring: ECG recommended before starting nortriptyline, especially in patients >65 years or with cardiac history 7
- Blood pressure: Monitor for orthostatic hypotension with nortriptyline 3
Off-Label Uses
Evidence-Supported Off-Label Indications
Postherpetic Neuralgia (PHN)
- Both agents have strong evidence individually 8, 6, 9
- Pregabalin is FDA-approved for PHN; combination may provide enhanced benefit
Fibromyalgia
Chronic Low Back Pain with Neuropathic Component
- Combination addresses both nociceptive and neuropathic elements 10
Cancer-Related Neuropathic Pain
HIV-Associated Peripheral Neuropathy
- Gabapentinoids are first-line; tricyclics are second-line 8
Trigeminal Neuralgia
- Pregabalin shows efficacy, particularly in elderly patients 9
Post-Surgical/Post-Traumatic Neuralgia
- Effective for preventing chronic pain development 9
Limited or Insufficient Evidence
- Carpal tunnel syndrome (use with caution due to nerve compression) 9
- Headache disorders (some evidence for pregabalin) 8
Common Pitfalls and Clinical Pearls
Pitfall #1: Starting Doses Too High
- Avoid: Starting with standard doses in elderly or frail patients
- Solution: Always start with pregabalin 75 mg and nortriptyline 10 mg, especially in patients >65 years 1, 4
Pitfall #2: Inadequate Trial Duration
- Avoid: Declaring treatment failure before 6-8 weeks
- Solution: Counsel patients that analgesic effect may take 2-4 weeks to manifest 1, 3
Pitfall #3: Abrupt Discontinuation
- Avoid: Stopping suddenly (risk of seizures with pregabalin, withdrawal symptoms with both)
- Solution: Taper gradually over 1-2 weeks minimum 6
Pitfall #4: Ignoring Anticholinergic Burden
- Avoid: Combining with other anticholinergic medications without monitoring
- Solution: Review medication list; consider secondary amine TCAs (nortriptyline) over tertiary amines (amitriptyline) for better tolerability 1, 7
Pitfall #5: Missing Cardiac Risk Factors
- Avoid: Prescribing nortriptyline >100 mg/day without ECG in cardiac patients
- Solution: Obtain baseline ECG; avoid if QTc prolonged or recent MI 7, 5
Adverse Effects to Monitor
Common (>10%)
- Dizziness and somnolence (most common with pregabalin) 6
- Dry mouth, constipation (nortriptyline) 1, 7
- Peripheral edema, weight gain (pregabalin) 6
Serious but Rare
- Angioedema (pregabalin) - discontinue immediately if facial/throat swelling occurs 6
- Respiratory depression (especially with opioids) 6
- Cardiac arrhythmias (nortriptyline at high doses) 7
- Suicidal ideation (both agents) - monitor mood changes 6
Management Strategy
- Start low, go slow
- Monitor weight and edema monthly
- Assess for falls risk in elderly
- Screen for mood changes at each visit
Comparative Effectiveness
Recent evidence suggests pregabalin-nortriptyline may be slightly less effective than pregabalin-duloxetine for pain reduction, sleep quality, and mood symptoms, but with fewer adverse events 2. However, nortriptyline remains preferred when:
- Cost is a significant factor
- Patient has contraindications to SNRIs
- Sedation at bedtime is desirable for comorbid insomnia 1
The combination approach is superior to monotherapy for refractory neuropathic pain 11, 12.