Duloxetine

Duloxetine should start helping with depression within one to two weeks. It may take four weeks or longer for you to get the full effect.

How people respond to treatment can vary. Sometimes improvement is slow, and you may not feel any different to start with. This can be hard when your mood is low, and if you experience any side effects from your medication you may think you feel worse and not better. If you can, give your medication a chance to work and continue to take it for at least three to four weeks to see if it makes a difference.

Your parents, friends and doctor may notice an improvement in you before you feel it yourself, so it’s a good idea to talk to them.

If you think your medicine has not made any difference to how you feel after three to four weeks, you should go back to your doctor. They might recommend a change in dose or a different medication. However, it can take longer to work for some people than for others, so they may suggest you wait six to eight weeks before deciding.

For anxiety, it may take longer for the benefits to be noticed. It could take up to three months before you feel the full benefit.

For some people, anxiety symptoms briefly increase at the start of treatment, but the anxiety should decrease over time as you continue to take your medicine. To avoid or minimise this, your doctor will usually start treatment with a low dose and increase this after one to two weeks.

Duloxetine can make you less hungry than normal, which might lead to weight loss.

In studies, some children and young people under 18 who took duloxetine had some weight loss at first, but after six months of treatment they went back to normal compared with other people of the same age.

It is not possible to predict how duloxetine will affect each person before they start taking it. Talk to your doctor or pharmacist if you are concerned about your weight, or changes to your weight, while taking duloxetine.

A common side effect of duloxetine is a dry mouth. Over a long time, this can increase your risk of developing tooth decay or gum disease. Make sure you brush your teeth well and have regular dental check-ups. Speak to your dentist, doctor or pharmacist about things you can do to help.

You may want to let your family and friends know you are taking duloxetine so they can support you and help you look out for side effects.

You can feel sleepy in the first few days of taking duloxetine. But this should get better after the first week or two. If it makes you tired, try taking it just before you go to bed.

It can also give you sleep problems, including unusual dreams. If you find it hard to get to sleep, try taking it in the morning.

If you experience any of these side effects and have been taking duloxetine for more than a month, you should go back to the doctor and discuss what changes could be made to help. This may include switching to a different medication.

Alcohol

It may be possible to drink some alcohol in moderation while taking duloxetine.

However, the two together might make you feel very sleepy and unsteady on your feet, especially when you first start taking the medication.

During the first few weeks of treatment, it is recommended that you don’t drink alcohol until you know how the medicine affects you.

Drinking alcohol every day, or in large amounts, can make your symptoms worse and may mean you won’t get the maximum benefit from your medication.

Street drugs

Cannabis can make drowsiness, dizziness and confusion worse when taken with duloxetine.

Cannabis and other drugs may have their own side effects on your mental health, like anxiety or psychosis.

Methadone can make sleepiness worse with duloxetine. The duloxetine could increase the concentration of methadone in your body. In some circumstances, you may be prescribed methadone by your doctor. If so, your doctor will monitor your medicines carefully and will adjust the dose if needed.

Duloxetine is likely to raise the effect of cocaine in your body, giving you a bigger reaction.

Taking duloxetine with cocaine or ecstasy or amfetamines could bring on serotonin syndrome. You could get a high temperature/fever, agitation, confusion, trembling or weird muscle movements. You need to go to hospital if this happens. Tell the doctor everything that you have taken.

There are many other street drugs, but we don’t know what effect taking them with duloxetine will have, so it’s best to be cautious. There is no regulation of street drugs or ‘legal highs’, so even if there are no known issues with the medication you take, the supply you receive might be mixed with other substances that could be dangerous.

Smoking

Cigarette smoke affects the amount of duloxetine in your body.

If you smoke, you will probably need a higher dose of duloxetine than someone who does not smoke.

Tell your doctor if you smoke, so that you get the right dose for you.

If you stop smoking or switch to vaping or a nicotine replacement product, the level of duloxetine in the body rises, and you might need to reduce your dose of duloxetine slowly. If you start or restart smoking, you will probably need to increase it again. Go to your doctor for advice if you stop or start smoking. It is the smoke, rather than nicotine, that has this effect so it should not be as much of a problem if you only vape.

Get more advice on drugs and alcohol.

Duloxetine does not mix well with some other medicines, including herbal remedies. It may affect how they work or could cause more side effects.

Do not take duloxetine if you take an antidepressant medicine called a monoamine oxidase inhibitor (MAOI), or if you have taken one in the last two weeks. MAOIs include drugs such as moclobemide, isocarboxazid, phenelzine and tranylcypromine.

Before you start taking duloxetine, tell your doctor if you are taking any other medications including things you have bought from a pharmacy or other shop for common illnesses like colds and flu or medications that you put on your skin.

Always tell the pharmacist that you are taking duloxetine if you buy any medicines from a pharmacy.

Look at the leaflet inside your medicine box for more information about other medicines that can interact with duloxetine. With some medicines your doctor may need to adjust the dose of your medicines if you take them together. Ask a doctor or pharmacist for more information if you have any questions.

The tablets may not be suitable for you if you have problems eating some sugars or dairy foods, as they contain sucrose.

Always let your pharmacist know if you have any food allergies or intolerances, and always check with them if you’re concerned about any of the ingredients in your medication.

If you need to avoid animal products such as gelatine, please note that this is often found in capsules but also in some tablet formulations. Ask your pharmacist if you have any questions about the ingredients.

Further information about practical considerations for medicines if you need to avoid animal products can be found on the Vegan Society website.

Taking duloxetine may affect your concentration, which could, in turn, affect your ability to do things like driving a car, riding a bike, using machines, or anything else that needs a lot of focus.

Duloxetine may also affect your eyesight and make you feel sleepy or dizzy.

It is recommended that you stop driving or riding a bike for the first few days or weeks, until you know how it affects you.

Most people drive as normal while taking duloxetine. If you are worried about this or have any concerns you would like to discuss, speak to your doctor or pharmacist.

Pregnancy

If you become pregnant while you are on duloxetine, you should carry on taking it and make an appointment to see your doctor as soon as possible They can discuss the benefits and risks of continuing duloxetine and help you to make a decision that is best for you and your baby. They may refer you to a specialist perinatal mental health team to support you with this decision.

You can find out more information about taking duloxetine during pregnancy Bumps (Best Use of Medicines in Pregnancy).

Untreated depression or anxiety can also be harmful to you and your developing baby, so decisions about stopping or avoiding medication when you are pregnant need to be discussed carefully with your doctor.

If you and your doctor agree that carrying on with duloxetine has more benefits than risks, you should tell your midwife that you are continuing to take this at your next appointment.

Some research has reported that taking antidepressants similar to duloxetine during the month before delivery can lead to a small increased risk of bleeding after you have given birth. It will be important for your doctor and midwife to know what medication you are taking so that appropriate monitoring and treatment is planned. If you are concerned about this, discuss it with your doctor and midwife.

If you are planning to get pregnant, it is recommended that you take folic acid while you are trying for a baby and during pregnancy. It is safe to take this together with duloxetine.

Post-natal

If duloxetine is taken in the last five months of a pregnancy, studies have shown a small increased risk of a condition called persistent pulmonary hypertension of the new-born (PPHN). PPHN can make the baby breathe faster and look a bit blue in colour.

This happens in the first 24 hours after birth. You will need help from the midwife and doctors, so it is best if they are looking out for symptoms.

The new born baby may also develop withdrawal effects such as:

• irritability and crying a lot
• having difficulty sleeping or sucking

These might not happen straight away, so you should look out for them over the first few days after the baby is born. These are usually mild and go away in a few days without treatment.

Breastfeeding

A small amount of duloxetine is passed to the baby in breast milk.

If your baby was born early, then breastfeeding while you are taking duloxetine may not be recommended. Talk to your midwife and doctor about feeding options.

If you breastfeed while taking duloxetine, seek urgent medical advice if your baby becomes restless, very sleepy, or develops feeding problems.

If your medication makes you sleepy, do not to sleep with your baby in the same bed, and be cautious when handling your baby (especially if waking during the night for feeds).

Sex

Duloxetine can have side effects that might affect your sex life. These include:

• problems getting an erection (getting hard) and ejaculating (coming)
• unusual bleeding from the vagina
• testicle pain
• changes in how you reach orgasm (come)
• having a lower sex drive (reduced libido)

Most side effects occur when you first start medication and improve over time. If they do not, and this is a problem for you, make an appointment to discuss this with your doctor.

Some other rare side effects include breast growth or milk flow from the breasts (regardless of gender). These may affect your confidence and therefore your desire to have sex. Talk to your doctor if you get these symptoms.

In medicines that are similar to duloxetine (SSRIs) there is some evidence to indicate that side effects affecting your sex life might continue for several months or longer after you stop your medicine. This is sometimes referred to as PSSD (post SSRI sexual dysfunction). We do not know if this is the case for duloxetine. More research is needed to understand how frequently this might happen. Discuss this with your doctor or pharmacist is you are concerned.

Untreated depression or anxiety can have a negative effect on your sex life, so if duloxetine helps you to recover, positive effects can include improving your desire, experience and enjoyment of sex as your mood lifts and you become interested in life and relationships again.

Fertility

There is no clear evidence that duloxetine affects female or male fertility at doses prescribed to treat depression or anxiety.

Talk to your doctor about your duloxetine if you are trying to get pregnant.

Duloxetine is not a banned substance in sport.

Most people play sports as normal while taking duloxetine. However, taking duloxetine may affect your ability to do things like riding a bike, competitive gymnastics, or anything else that needs a lot of focus. It can affect your eyesight, make you feel dizzy and sleepy, and make you feel restless and unable to sit still.

It might be best to stop such sports for the first few days, until you know how it affects you or the effects get better.

If you are worried that taking duloxetine might make doing the sports you enjoy more difficult, discuss this with your doctor.

Ideally it is best not to take duloxetine for the first time just before your exams.

Taking duloxetine may affect your ability to do things that need a lot of focus, like revising and exams. Your eyesight may be affected, and you might have sleep problems or feel very sleepy during the day. You may also feel restless and find it hard to sit down and keep still.

You should talk to your doctor about any future exams if you are starting duloxetine. You might decide together to delay starting it until you have done them. If they are more than a month away, however, you might find that it is better to start duloxetine to lift your mood and improve your motivation and ability to study.

Most people take exams as normal while taking duloxetine. It you are worried that taking duloxetine might make studying for or taking your exams harder, discuss this with your doctor.