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Active substance: ZIDOVUDINE

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300 mg film-coated tablets

Information for the patient
Read all of this leaflet carefully before you start using this medicine because it contains important
information for you.
Keep this leaflet. You may need to read it again.
If you have any further questions, ask your doctor or pharmacist.
This medicine has been prescribed for you only. Do not pass it on to others. It may harm them even if
their signs of illness seem to be the same as yours.
If you get any side effects talk to your doctor or pharmacist. This includes any possible side
effects not listed in this leaflet. See section 4.

What is in this leaflet
1 What Retrovir is and what it is used for
2 What you need to know before you take Retrovir
3 How to take Retrovir
4 Possible side effects
5 How to store Retrovir
6 Contents of the pack and other information


What Retrovir is and what it is used for
Retrovir is used to treat HIV (human immunodeficiency virus) infection.
The active ingredient in Retrovir is zidovudine. Retrovir is a type of medicine known as an antiretroviral. It belongs to a group of medicines called nucleoside analogue reverse transcriptase
inhibitors (NRTIs).
Retrovir does not get rid of HIV infection; it reduces the amount of virus in your body, and keeps it at
a low level. Retrovir also increases the CD4 cell count in your blood. CD4 cells are a type of white
blood cells that are important in helping your body to fight infection.
Retrovir is used, in combination with other medicines (‘combination therapy’), to treat HIV in adults
and children. To control your HIV infection, and to stop your illness getting worse, you must keep
taking all your medicines.
If you’re pregnant, your doctor may want you to take Retrovir, to help prevent you passing HIV on to
your unborn baby. After the birth, your baby may be given Retrovir to help prevent it from getting
infected with HIV.
HIV infection is spread by sexual contact with someone who’s got the infection, or by transfer of
infected blood (for example, by sharing injection needles).


What you need to know befor e you take Retr ovir

Don’t take Retrovir:
• if you’re allergic (hypersensitive) to zidovudine or any of the other ingredients of Retrovir (listed
in Section 6)
• if you have a very low white blood cell count (neutropenia) or a very low red blood cell count

Retrovir for new-born babies
Retrovir must not be given to some new-born babies with liver problems, including:
• some cases of hyperbilirubinaemia (increased amounts in the blood of a substance called bilirubin
which may make the skin appear yellow)
• other problems which cause high levels of liver enzymes in the blood.

Take special care with Retrovir
Some people taking Retrovir or combination therapy for HIV are more at risk of serious side effects.
You need to be aware of the extra risks:
• if you have ever had liver disease (including hepatitis B or C)
• if you’re seriously overweight (especially if you’re a woman)
• if you’re diabetic and using insulin.
 Talk to your doctor if any of these applies to you. You may need extra check-ups, including
blood tests, while you’re taking your medication. See Section 4 for more information.

Look out for important symptoms
Some people taking medicines for HIV infection develop other conditions, which can be serious. You
need to know about important signs and symptoms to look out for while you’re taking Retrovir.
Please read the information in Section 4 of this leaflet. If you have any questions about this
information or the advice given:
 Talk to your doctor.

Other medicines and Retrovir
Tell your doctor or pharmacist if you’re taking any other medicines, or if you’ve taken any
recently, including herbal medicines or other medicines you bought without a prescription. Remember
to tell your doctor or pharmacist if you begin taking a new medicine while you’re taking Retrovir.

Don’t take these medicines with Retrovir:
• stavudine, used to treat HIV infection
• ribavirin or injections of ganciclovir to treat viral infections
• rifampicin, which is an antibiotic.


Some medicines can make it more likely that you’ll have side effects, or make side effects
These include:
• sodium valproate, used to treat epilepsy
• aciclovir, ganciclovir or interferon, used to treat viral infections
• pyrimethamine, used to treat malaria and other parasitic infections
• dapsone, used to prevent pneumonia and treat skin infections
• fluconazole or flucytosine, used to treat fungal infections such as candida
• pentamidine or atovaquone, used to treat parasitic infections such as PCP
• amphotericin or co-trimoxazole, used to treat fungal and bacterial infections
• probenecid, used to treat gout and similar conditions, and given with some antibiotics to make
them more effective
• methadone, used as a heroin substitute
• vincristine, vinblastine or doxorubicin, used to treat cancer.
 Tell your doctor if you’re taking any of these.

Some medicines interact with Retrovir
These include:
• clarithromycin, which is an antibiotic
• phenytoin, used for treating epilepsy.
 Tell your doctor if you’re taking clarithromycin or phenytoin. Your doctor may need to monitor
you while you’re taking Retrovir.

If you are pregnant, if you become pregnant, or if you’re planning to become pregnant:
 Talk to your doctor about the risks and benefits of taking Retrovir.
If pregnant women who are HIV-positive take Retrovir, they are less likely to pass the HIV infection
on to their unborn babies.
Retrovir and similar medicines may cause side effects in unborn babies; if it does, these effects won’t
show up until after the baby has been born. Even so, the benefit of protecting your baby from getting
HIV is greater than the risk of your baby getting side effects.
If you’ve taken Retrovir while you were pregnant, your baby may be given extra check-ups (which
may include blood tests), to make sure it’s developing normally.

Breast feeding
Women who are HIV-positive must not breast feed, because HIV infection can be passed on to the
baby in breast milk. A small amount of the ingredients in Retrovir can also pass into your breast milk.
If you are breast feeding, or thinking about breast feeding:
 Talk to your doctor immediately.


Driving and using machines
Retrovir can make you dizzy and have other side effects that make you less alert.
 Don’t drive or operate machinery unless you’re feeling well.

You will need regular blood tests
For as long as you’re taking Retrovir, your doctor will arrange regular blood tests to check for side
effects. There’s more information about these side effects in Section 4 of this leaflet.

Stay in regular contact with your doctor
Retrovir helps to control your condition, but it is not a cure for HIV infection. You need to keep taking
it every day to stop your illness getting worse. You may still develop other infections and illnesses
linked to HIV infection.
 Keep in touch with your doctor, and don’t stop taking Retrovir without your doctor’s advice.

Protect other people

HIV infection is spread by sexual contact with someone who has the infection, or by transfer of
infected blood (for example, by sharing injection needles). You can still pass on HIV when taking this
medicine, although the risk is lowered by effective antiretroviral therapy.

Discuss with your doctor the precautions needed to avoid infecting other people.


How to take Retrovir
Always take this medicine exactly as your doctor has told you to. Check with your doctor or
pharmacist if you’re not sure.
Swallow the tablets whole, with some water.

How much Retrovir will you need to take?
Adults and adolescents weighing at least 30 kg:
The usual dose of Retrovir is 300 mg twice a day. Take each tablet 12 hours apart.
Your child can take Retrovir in liquid form or as 100 mg capsules.
Pregnancy, childbirth and newborn babies:
You should not normally take Retrovir during the first 14 weeks of your pregnancy. After week 14,
the usual dose is 500 mg each day given as 100 mg five times per day until you start to go into labour.
During the labour and birth, your doctor may give you injections of Retrovir, until your baby’s
umbilical cord has been clamped. Your new-born baby may also be given Retrovir to help prevent it
from getting infected with HIV.
People with kidney or liver problems:
If you have severe kidney or liver problems, you may be given a lower dose of Retrovir, depending on
how well your kidneys or liver are working. Follow your doctor’s advice.


If you take too much Retrovir
If you accidentally take too much Retrovir, it is unlikely to cause you serious problems. The most
common effects of taking too much Retrovir are tiredness, headaches and being sick (vomiting). If you
feel unwell:
 Ask your doctor or pharmacist for advice.

If you forget to take Retrovir
If you forget to take a dose, don’t worry. You can take your next dose as soon as you remember but
not within two hours of your next dose. If you remember within two hours of your next dose, just skip
the dose you missed and take your next dose at the usual time. Then continue your treatment as before.
Don’t take a double dose to make up for a missed dose.

Don’t stop taking Retrovir without advice
Take Retrovir for as long as your doctor recommends. Don’t stop unless your doctor advises you


Possible side effects
Like all medicines, this medicine can cause side effects, but not everyone gets them. Some side effects
may show up in your blood tests, and may not appear until 4 to 6 weeks after you start taking Retrovir.
If you get any of these effects, and if they are severe, your doctor may advise you to stop taking
As well as the effects listed below, other conditions can develop during combination therapy for HIV.
 It is important to read the information in ‘Other possible side effects of combination therapy for

Very common side effects
These may affect more than 1 in 10 people taking Retrovir:
• headaches
• feeling sick (nausea).

Common side effects
These may affect up to 1 in 10 people taking Retrovir:
• being sick (vomiting)
• diarrhoea
• stomach pains
• feeling dizzy
• aching muscles
• generally feeling unwell.
Common side effects that may show up in your blood tests are:
• a low red blood cell count (anaemia) or low white blood cell count (neutropenia or leucopenia)
• an increase in the level of liver enzymes


• an increased amount in the blood of bilirubin (a substance produced in the liver) which may make
your skin appear yellow.

Uncommon side effects
These may affect up to 1 in 100 people taking Retrovir:
• skin rash (red, raised or itchy skin)
• feeling breathless
• fever (high temperature)
• general aches and pains
• wind (flatulence)
• weakness.
Uncommon side effects that may show up in your blood tests are:
• a decrease in the number of cells involved in blood clotting (thrombocytopenia), or in all kinds of
blood cells (pancytopenia).

Rare side effects
These may affect up to 1 in 1000 people taking Retrovir:
• liver disorders, such as jaundice, enlarged liver or fatty liver
• inflammation of the pancreas
• chest pain; disease of the heart muscle
• fits (convulsions)
• feeling depressed or anxious; not being able to sleep (insomnia); not being able to concentrate;
feeling drowsy
• indigestion; loss of appetite; taste disturbance
• changes in the colour of your nails, your skin, or the skin inside your mouth
• a flu-like feeling — chills, sweating and cough
• tingly feelings in the skin (pins and needles)
• passing urine more often
• enlarged breasts in men.
A rare side effect that may show up in your blood tests is:
• a decrease in the number of a type of red blood cell (pure red cell aplasia).

Very rare side effects
A very rare side effect that may affect up to 1 in 10,000 people taking Retrovir, and may show up in
blood tests is:
• a failure of the bone marrow to produce new blood cells (aplastic anaemia).

If you get any side effects
 Talk to your doctor or pharmacist. This includes any possible side effects not listed in this


Other possible side effects of combination therapy for HIV
Some other conditions may develop during HIV treatment.

Old infections may flare up
People with advanced HIV infection (AIDS) have weak immune systems, and are more likely to
develop serious infections (opportunistic infections). When these people start treatment, they may find
that old, hidden infections flare up, causing signs and symptoms of inflammation. These symptoms are
probably caused by the body’s immune system becoming stronger, so that the body starts to fight these
In addition to the opportunistic infections, autoimmune disorders (a condition that occurs when the
immune system attacks healthy body tissue) may also occur after you start taking medicines for the
treatment of your HIV infection. Autoimmune disorders may occur many months after the start of
treatment. If you notice any symptoms of infection or other symptoms such as muscle weakness,
weakness beginning in the hands and feet and moving up towards the trunk of the body, palpitations,
tremor or hyperactivity, please inform your doctor immediately to seek necessary treatment.
If you get any symptoms of infection while you’re taking Retrovir:
 Tell your doctor immediately. Don’t take other medicines for the infection without your doctor’s

Your body shape may change
People taking combination therapy for HIV may find that their body shape changes, because of
changes in fat distribution:
• Fat may be lost from the legs, arms or face.
• Extra fat may build up around the tummy (abdomen), or on the breasts or internal organs.
• Fatty lumps (sometimes called buffalo hump) may appear on the back of the neck.
It is not yet known what causes these changes, or whether they have any long-term effects on your
health. If you notice changes in your body shape:
 Tell your doctor.

Lactic acidosis is a rare but serious side effect
Some people taking Retrovir, or other medicines like it (NRTIs), develop a condition called lactic
acidosis, together with an enlarged liver. Lactic acidosis is caused by a build-up of lactic acid in the
body. It is rare; if it happens, it usually develops after a few months of treatment. It can be lifethreatening, causing failure of internal organs.
Lactic acidosis is more likely to develop in people who have liver disease, or in obese (very
overweight) people, especially women.

Signs of lactic acidosis include:
• deep, rapid, difficult breathing
• drowsiness
• numbness or weakness in the limbs
• feeling sick (nausea), being sick (vomiting)
• stomach pain.


During your treatment, your doctor will monitor you for signs of lactic acidosis. If you have any of the
symptoms listed above, or any other symptoms that worry you:
 See your doctor as soon as possible.

You may have problems with your bones
Some people taking combination therapy for HIV develop a condition called osteonecrosis. With this
condition, parts of the bone tissue die because of reduced blood supply to the bone.
People may be more likely to get this condition:
• if they have been taking combination therapy for a long time
• if they are also taking anti-inflammatory medicines called corticosteroids
• if they drink alcohol
• if their immune systems are very weak
• if they are overweight.

Signs of osteonecrosis include:
• stiffness in the joints
• aches and pains (especially in the hip, knee or shoulder)
• difficulty moving.
If you notice any of these symptoms:
 Tell your doctor.

Other effects may show up in tests
Combination therapy for HIV can also cause:
• increased levels of lactic acid in the blood, which on rare occasions can lead to lactic acidosis
• increased levels of sugar, fatty acids (triglycerides) and cholesterol in the blood
• resistance to insulin (so if you’re diabetic, you may have to change your insulin dose to control
your blood sugar).
These effects may show up in the blood tests you’ll have while you’re taking Retrovir.
Reporting of side effects
If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed
in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: By reporting side effects you can help provide more information on the
safety of this medicine.


How to store Retrovir
Keep this medicine out of the sight and reach of children.
Don’t take this medicine after the expiry date shown on the carton.
Don’t store Retrovir above 30 °C (86 °F).
Store it in its original package.
Don’t throw away any medicines via waste water or household rubbish. Ask your pharmacist how to
throw away medicines you no longer use. This will help protect the environment.


Contents of the pack and other information

What Retrovir contains
The active substance is zidovudine.
The other ingredients are: microcrystalline cellulose, sodium starch glycollate, povidone K30,
magnesium stearate, OPADRY (OY-7300): hypromellose, titanium dioxide (E171), macrogol 400 and
macrogol 8000.

What Retrovir looks like and contents of the pack
Retrovir 300 mg film-coated tablets are marked ‘WELLCOME X4F’. They are white and round
with a white to beige core, and supplied in bottles of 28 tablets or foil blister packs of 300, 28 or 60

Marketing Authorisation Holder and Manufacturer
Marketing authorisation holder
ViiV Healthcare UK Ltd, 980 Great West Road, Brentford, Middlesex TW8 9GS
Glaxo Wellcome S.A., Avenida de Extremadura 3, 09400 Aranda de Duero, Burgos, Spain
Other formats:
To listen to or request a copy of this leaflet in Braille, large print or audio please call, free of charge:
0800 198 5000 (UK Only)
Please be ready to give the following information:
Product name
Retrovir 300 mg Tablets
Reference number
This is a service provided by the Royal National Institute of Blind People.
Leaflet date: March 2015
Retrovir is a registered trade mark of the ViiV Healthcare group of companies.
© 2014 ViiV Healthcare group of companies. All rights reserved.
ViiV Healthcare logo


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Source: Medicines and Healthcare Products Regulatory Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.