Duloxetine: depression, anxiety and nerve pain

Duloxetine is classed as a serotonin and noradrenaline reuptake inhibitor. By raising these two chemicals it can lift mood and calm anxiety. The NHS also says that for nerve pain it reduces the pain messages nerves send to the brain.

Its licensed uses therefore span depression, anxiety, nerve pain including fibromyalgia, and stress urinary incontinence in women. Which one applies to you depends on why it was prescribed, and the label will reflect that.

• Depression and anxiety

• Nerve pain, including fibromyalgia

• Stress urinary incontinence in women

It comes as capsules that you swallow whole with water. Depending on the reason and the dose, you may take it once or twice a day, with or without food. A doctor may begin at a low dose and increase it after a week.

If you miss a dose, take it as soon as you remember unless the next dose is close. In that case skip it, and never double up.

If you take too much, the NHS says to call NHS 111 and, if sent to A&E, to bring the packet and a list of your other medicines.

The NHS says that most common side effects ease after a couple of weeks. Speak to a pharmacist or doctor if they are troublesome.

• Common: headaches, nausea, vomiting, dizziness, drowsiness, dry mouth, diarrhoea or constipation, insomnia, sexual problems and weight loss.

• Avoid driving or machinery if you feel dizzy or drowsy.

• Call NHS 111 for an allergic reaction, serotonin syndrome, unexplained muscle pain or weakness, mania or hypomania, or thoughts of harming yourself.

The NHS lists epilepsy, heart disease, glaucoma and a history of mania as reasons to discuss duloxetine before starting. Mention any other medicines and supplements, including those bought without prescription.

It can help to keep a short list on your phone of every medicine, vitamin and herbal product you use, and to show it at each review. That list is the quickest way for a pharmacist to spot a clash, and it matters more with duloxetine because it is often prescribed alongside painkillers or other medicines for long-term conditions. Tell the prescriber too if your symptoms change, if you start a new medicine, or if you are planning a pregnancy. Bring the list to any appointment about your pain or your mood, since both are often reviewed together.

Blood thinners, anti-inflammatory painkillers and MAOI antidepressants can interact with duloxetine, and St John's wort should be avoided. Because nerve pain is often treated with several medicines at once, ask the pharmacist to check the whole list.

Alcohol increases the risk of side effects.

The NHS says duloxetine can be used during pregnancy at the lowest effective dose if the benefits outweigh the risks. It enters breast milk, so discuss feeding with your doctor.

Do not stop suddenly; the dose is reduced gradually over several weeks or months to avoid withdrawal symptoms. If you notice a suspected side effect, it can be reported to the MHRA Yellow Card scheme.