Solifenacin is a medicine used to treat symptoms of an overactive bladder. These can include:

• a sudden and urgent need to pee (urinary urgency)
• needing to pee more often than usual (urinary frequency)
• wetting yourself if you cannot make it to the loo in time (urinary incontinence)

Solifenacin works by relaxing the muscles around your bladder. This means your bladder can hold more liquid and you do not need to pee as often or as urgently.

Solifenacin is only available on prescription. It comes as tablets and as a liquid that you swallow.

Solifenacin also comes combined with tamsulosin, a medicine for prostate problems. Solifenacin with tamsulosin is known as Vesomni. Your doctor may prescribe this to treat a sudden and urgent need to pee if you have an enlarged prostate.

• You'll usually take solifenacin once a day.
• Common side effects include dry mouth and blurred vision.
• You will usually take this medicine long term to help keep your symptoms under control.
• Solifenacin starts to work within 3 to 8 hours, but it can take up to 4 weeks to reach its full effect.

Solifenacin can be taken by adults (aged 18 years and over).

It's not suitable for everyone. To make sure it's safe for you, tell your doctor or pharmacist before starting solifenacin if you:

• have ever had an allergic reaction to solifenacin or any other medicine
• have liver or kidney problems
• have myasthenia gravis, a rare long-term condition that causes muscle weakness
• have glaucoma, as solifenacin can increase pressure in your eye
• have a severe stomach or bowel condition, including a rare complication of ulcerative colitis or Crohn's disease called toxic megacolon
• are not able to pee or empty your bladder completely (urinary retention)
• are pregnant, trying to get pregnant or breastfeeding

Always read the information that comes with your medicine.

You'll usually take solifenacin once a day. You can take your dose at any time but try to take it at the same time each day.

Swallow your tablets whole with a drink of water, do not chew or crush them. You can take solifenacin with or without food.

Dosage

The usual dose of solifenacin is 5mg, taken once a day. If your symptoms do not improve, your doctor may increase your dose to 10mg a day.

The usual dose for solifenacin with tamsulosin (Vesomni) is 1 tablet once a day.

What if I forget to take it?

If you forget to take a dose, take it as soon as you remember. If you do not remember until the following day, skip the missed dose and take your next one at the normal time.

Do not take a double dose to make up for a missed dose.

If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

What if I take too much?

Taking 1 extra dose of solifenacin is unlikely to harm you.

However, you may get more side effects, such as a dry mouth or headache.

The amount of solifenacin that can lead to an overdose varies from person to person, and too much solifenacin can be dangerous.

Like all medicines, solifenacin can cause side effects although not everyone gets them. Side effects often improve as your body gets used to the medicine.

Common side effects

Common side effects happen in more than 1 in 100 people. They are usually mild and short-lived.

Talk to your doctor or pharmacist if these side effects bother you or do not go away:

• dry mouth
• headache
• feeling dizzy, sleepy, or a spinning sensation (vertigo)
• diarrhoea or being sick (vomiting)
• constipation
• farting and burping (wind)
• stomach pain
• dry eyes
• blurred vision
• problems or pain when peeing, and not being able to empty your bladder

Serious side effects

Serious side effects are rare.

Tell your doctor straight away if you have:

• stomach pain (especially after meals), feeling sick or being sick, a persistent urge to poo, not being able to poo or you have runny poos – these are all signs of faecal impaction, where large, hardened poo gets stuck and you cannot push it out
• difficulty fully emptying your bladder, or difficulty in starting to pee – these are signs of urinary retention, where pee builds up in your bladder because you're unable to pee
• high temperature or chills, burning sensation when peeing, pain in your back or side, or bloody or cloudy pee – these can be signs of a severe urinary tract infection (UTI)
• swollen ankles or legs (oedema) – where fluid builds up in your legs

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to solifenacin.

What to do about:

• dry mouth – try chewing sugar-free gum or having sugar-free sweets. Having a dry mouth can cause tooth decay or a fungal infection. It also might stop medicine that you put under your tongue from dissolving properly, such as medicine for angina.
• headache – make sure you rest and drink plenty of fluids. Avoid alcohol. Ask your pharmacist to recommend a painkiller. Talk to your doctor if your headache is severe or lasts longer than 1 or 2 days.
• feeling dizzy, sleepy or a spinning sensation – do not drive, cycle, use tools, or operate machinery. Avoid drinking alcohol, as this may make your symptoms worse. Talk to your doctor if the dizziness or sleepiness bothers you.
• diarrhoea or being sick – drink lots of water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having strong-smelling pee. Do not take any other medicines without speaking to a pharmacist or doctor, if the effects last more than 1 or 2 days.
• constipation – get more fibre into your diet, such as fresh fruit and vegetables and cereals, and drink plenty of water. Try to exercise more regularly, for example, by going for a daily walk or run. If this does not help, talk to a pharmacist or doctor. Watch this short video about how to treat constipation.
• farting and burping – eat less foods that cause wind, like lentils, peas, beans and onions. It might also help to eat smaller and more frequent meals, eat and drink slowly, and exercise regularly. Ask your pharmacist about remedies you can buy to help with trapped wind.
• stomach pain – try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Try putting a heat pad or a covered hot water bottle on your stomach to help. If you are in a lot of sudden severe pain, speak to your pharmacist or doctor.
• dry eyes – ask your pharmacist or optician to recommend some eye drops. If you wear contact lenses and these become uncomfortable, you might have to wear glasses instead while you're taking this medicine.
• blurred vision – do not drive or ride a bike until you can see clearly again. Do not take your next dose of solifenacin if your vision is still blurred. Speak to your doctor or pharmacist if your vision has not returned to normal a day after taking your last dose.
• problems or pain when peeing – try to relax when you pee. Do not try to force the flow of urine. If it does not happen, try again later. Talk to a doctor urgently if you cannot pee at all.

Solifenacin is not usually recommended in pregnancy because there's not enough information available to say if it's safe for you and your baby.

If you're trying to get pregnant or you're already pregnant, talk to your doctor about whether taking solifenacin is right for you.

Solifenacin and breastfeeding

Solifenacin is not usually recommended while breastfeeding. However, some breastfeeding mothers may still need it.

It is not known how much solifenacin gets into breast milk, but this is likely to be small. However, there's a risk your baby might have some side effects. Your doctor may therefore advise that you take an alternative medicine.

If your doctor says it's ok for you to keep taking solifenacin, monitor your baby for possible side effects, such as constipation, peeing less and colic.

Talk to your doctor, midwife or health visitor if you have any concerns about your baby while you're breastfeeding, including if you do not think your baby is putting on enough weight.

For more information about how solifenacin can affect you and your baby during pregnancy, read this leaflet on treating urinary incontinence on the Best Use of Medicines in Pregnancy (BUMPs) website.

Some medicines and solifenacin can affect each other. This can increase the chance of side effects.

Tell your pharmacist or doctor if you're taking:

• any medicine that makes you drowsy, gives you a dry mouth, or makes it difficult for you to pee. Taking solifenacin might make these side effects worse
• ketoconazole or itraconazole, medicines used to treat fungal infections
• ritonavir, a medicine used to treat HIV

Mixing solifenacin with herbal remedies and supplements

Some herbal products such as turmeric may change the way your body processes solifenacin.

There's very little information about taking solifenacin with other herbal remedies and supplements.

Some herbal medicines can make you feel sleepy, cause a dry mouth, or make it difficult to pee. Their effect is similar to solifenacin. This can increase your risk of getting side effects or make your side effects worse.