Duloxetine

Duloxetine is used to try and reduce pain in fibromyalgia and neuropathic (nerve) pain. This means it ca be good at reducing sensations such as hot, burning, throbbing, shooting, stabbing, sharp, cramping, aching, tingling, numbness, pins and needles pain and for pain that keeps you awake at night.

You may start to feel a bit better after a week, but it can take up to two months to feel the full effect. Your doctor might need to increase your dose to get the best results, and they will tell you if this is needed. Duloxetine does not always work for everyone, however if you do not feel any benefit from this medicine, do not stop it suddenly, speak to your doctor first.

The capsules should be swallowed whole with water, with or without food.

It is recommended duloxetine is taken once a day usually in the morning at about the same time each day. Taking it at the same time each day will have the best effect and help you remember to take it.

Duloxetine comes in different strength capsules. A typical starting dose is 30 to 60 mg taken once a day.

Duloxetine can interact with other medicines, e.g. warfarin, tramadol and herbal products.  Always tell your doctor, nurse or pharmacist which other medicines you are taking or planning to take, so they can make sure there are no interactions between your medicines.

Treatment with duloxetine will continue as long as it works well and there are no serious side effects .

If you stop duloxetine treatment for more than a few weeks there is a risk that your condition may get worse. Continue with your treatment unless advised by your doctor or unless side effects develop.

You might experience side effects with your treatment. Tell your doctor if you are concerned about possible side effects.

Reducing the dose might help reduce side effects so you can keep taking duloxetine. Your doctor will tell you if any dose changes are needed.

Most common possible side effects

The most common side effects for this medicine are;

• stomach pain, nausea or vomiting and constipation
• dry mouth
• dizziness.

Duloxetine can also cause trouble sleeping (insomnia) in some people but in other people it can cause drowsiness. It is recommended that you take duloxetine in the morning with food when you first start taking it. If you find that it makes you sleepy during the day, you can try taking it at night instead. 

If you experience any other side effects (anything unusual within a few days of starting the medicine) you should stop taking duloxetine and inform your doctor.

Less common or rare possible side effects

Contact your doctor if you experience one of these:

• Blurry vision – Duloxetine can cause blurry vision. Tell your doctor if you have glaucoma before starting this medicine.
• Blood pressure – Duloxetine can sometimes in rare cases, cause an increase in blood pressure. Your doctor will monitor this. Let your doctor know if you have high blood pressure.
• Increased sweating – Duloxetine can sometimes cause increased sweating.
• Headache – Duloxetine can sometimes cause headaches.
• Bladder problems – Duloxetine can cause difficulties passing urine.
• Liver failure, yellowing of the skin or whites of the eyes (jaundice)
• Serious allergic reaction which causes difficulty in breathing or dizziness with swollen tongue or lips.

More information about possible side effects

Information that comes with your duloxetine medicine describes in detail potential serious side effects that may occur with duloxetine.

Blood tests

Patients who take duloxetine should get occasional blood tests as requested by their doctor. It is important make sure duloxetine isn’t affecting the liver.

Use with alcohol

Drinking alcohol while taking duloxetine is not recommended because both can affect the liver. Patients should avoid alcohol completely, or only drink small amounts of alcohol.

• Keep your capsules in a cool dry place where the temperature stays below 25°C.  Do not store duloxetine or any other medicine in the bathroom or near a sink. Do not leave it on a windowsill or in the car on hot days. Heat and dampness can destroy some medicines.
• Keep it where children cannot reach it. A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.
• Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use.