Duloxetine 💊
Always check the BNF link here before prescribing.
- 💊 Duloxetine is a serotonin–noradrenaline reuptake inhibitor (SNRI).
- Licensed for depression, anxiety, diabetic neuropathy, and stress urinary incontinence.
- Particularly useful in patients with both depression and neuropathic pain.
⚙️ Mode of Action
- Inhibits presynaptic reuptake of serotonin and noradrenaline → increases their availability at the synaptic cleft.
- ➡️ Enhances descending inhibitory pain pathways and improves mood/anxiety symptoms.
📋 Indications / Dose
- 🧠 Major Depressive Disorder: 60 mg OD (max 120 mg/day).
- 😟 Generalised Anxiety Disorder: 30–120 mg OD.
- 🦶 Diabetic Peripheral Neuropathy: 60 mg OD. Stop if no benefit after 2 months (max 120 mg/day).
- 🚻 Stress Urinary Incontinence (moderate–severe): 40 mg BD, reassess after 2–4 weeks.
🔄 Interactions
- See BNF for full list.
- ⚠️ Avoid with MAOIs or within 14 days of discontinuation → risk of serotonin syndrome.
- CYP1A2 and CYP2D6 inhibitors (e.g. ciprofloxacin, fluoxetine) ↑ duloxetine levels.
- Increased bleeding risk with NSAIDs, aspirin, or anticoagulants.
⛔ Contraindications
- Severe hepatic impairment (risk of hepatotoxicity).
- Severe renal impairment (CrCl <30 mL/min).
- Uncontrolled hypertension.
- Concurrent MAOI therapy.
⚠️ Cautions
- History of mania or bipolar disorder.
- Seizure disorders.
- Elderly (falls risk, hyponatraemia).
- Bleeding disorders (platelet inhibition).
- Angle-closure glaucoma (pupil dilatation risk).
- Cardiac disease (can cause tachycardia, BP changes).
💊 Side Effects
- GI: anorexia, nausea, vomiting, abdominal pain, constipation.
- Neuro: dizziness, headache, insomnia, somnolence.
- CVS: palpitations, hypertension, orthostatic hypotension.
- Other: dry mouth, sweating, fatigue, sexual dysfunction.
- Rare: hepatotoxicity, hyponatraemia, serotonin syndrome, suicidal ideation (esp. early treatment).
📝 Clinical Pearls
- Assess BP before and during treatment (risk of hypertension).
- Warn about withdrawal symptoms (dizziness, irritability, flu-like illness) if stopped abruptly – taper over weeks.
- Useful choice in patients with both neuropathic pain and depression.
- Monitor liver function in patients with risk factors for hepatic disease.
- Therapeutic effect in mood disorders may take 2–4 weeks.
📚 References
