How does it work?

Lyrinel XL tablets contain the active ingredient oxybutyninhydrochloride, which is a type of medicine called an anticholinergic (orantimuscarinic) muscle relaxant. It works by relaxing the involuntary musclethat is found in the wall of the bladder.

The muscle in the wall of the bladder is called the detrusormuscle. It can sometimes contract in uncontrollable spasms, and this is oftenreferred to as having an overactive or unstable bladder. The overactivedetrusor muscle can cause an increase in the number of times you need to passurine, uncontrollable urges to pass urine, or involuntary leakage of urine(urinary incontinence).

Oxybutynin works by relaxing the detrusor muscle in the wall ofthe bladder. It does this by blocking receptors called cholinergic (ormuscarinic) receptors that are found on the surface of the muscle cells. Thisprevents a natural body chemical called acetylcholine from acting on thesereceptors.

Normally when acetylcholine acts on these receptors, it causesthe detrusor muscle to contract and the bladder to empty. By blockingacetylcholine, oxybutynin helps the muscle in the bladder wall to relax. Thisreduces unstable, involuntary contractions of the bladder, and therebyincreases the capacity of the bladder to hold urine. In turn, this reduces theneed to pass urine.

Oxybutynin is used to treat urinary frequency, urinary urgencyand incontinence in people with unstable bladders. The condition may have noknown cause (idiopathic bladder instability), or may be due to problems withthe nerve supply to the bladder (neurogenic bladder), for example following aspinal cord injury, or as a result of conditions affecting the nervous systemsuch as spina bifida or multiple sclerosis.

Lyrinel XL tablets are known as prolonged release tablets. Theyare designed to release the medicine slowly over the day as the tablet passesthrough the gut. This means the tablets only need to be taken once a day. Thetablets should be swallowed whole with liquid and not broken, chewed orcrushed, as this would stop their prolonged release action from working.

What is it used for?

• Urinary incontinence, urgency and frequency in adults and elderly people with an unstable bladder.
• Improving bladder control in children over six years of age with diseases of the nervous system that cause problems with the nerve supply to the bladder.

Warning!

• This medicine may cause drowsiness and blurred vision. If affected do not drive or operate machinary.
• Contact your doctor immediately if your experience a sudden change in your eyesight while taking this medicine, such as a reduced ability to see fine detail.
• This medicine may reduce sweating, and this may cause you to become overheated or faint in hot environments, or if you have a fever. Discuss this with your doctor.
• The membrane of Lyrinel XL tablets may pass through the gut unchanged and be visible in the stools. This is normal, and does not affect the action of the medicine.

Use with caution in

• Elderly people
• Children
• Decreased kidney function
• Decreased liver function
• Gastro-oesophageal reflux, eg due to a hiatus hernia
• Decreased motility of the stomach or intestines
• Obstruction of the outflow of urine from the bladder
• Enlarged prostate gland (benign prostatic hyperplasia)
• Overactive thyroid gland (hyperthyroidism)
• High blood pressure (hypertension)
• Heart failure
• Irregular heart beats (arrhythmias)
• Increased heart rate (tachycardia)
• Coronary artery disease.

Not to be used in

• Children under six years of age
• Urinary frequency and excessive need to pass urine at night as a result of heart failure or kidney failure
• Inability to pass urine (urinary retention)
• Closed angle glaucoma
• Abnormal muscle weakness (myasthenia gravis)
• Blockage of the stomach or intestines (gastrointestinal obstruction)
• Paralysis or inactivity in the intestines that prevents material moving through the gut (intestinal atony or paralytic ileus)
• Severe inflammation of the bowel and back passage (ulcerative colitis)
• Sudden expansion of the large intestine seen in advanced ulcerative colitis or Crohn's disease (toxic megacolon)
• Hereditary blood disorders called porphyrias
• Breastfeeding
• Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Lyrinel XL tablets contain lactose).

This medicine should not be used if you are allergic to one orany of its ingredients. Please inform your doctor or pharmacist if you havepreviously experienced such anallergy.If you feel you haveexperienced an allergic reaction, stop using this medicine and inform yourdoctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy orbreastfeeding. However, other medicines may be safely used in pregnancy orbreastfeeding providing the benefits to the mother outweigh the risks to theunborn baby. Always inform your doctor if you are pregnant or planning apregnancy, before using any medicine.

• The safety of this medicine for use during pregnancy has not been established. It is not recommended for use during pregnancy, unless the potential benefits to the mother outweigh any possible risks to the developing baby. Seek medical advice from your doctor.
• This medicine may pass into breast milk. It should not be used by breastfeeding mothers. Seek further medical advice from your doctor.

Label warnings

• This medication is to be swallowed whole, not chewed.
• This medication may cause drowsiness. If affected do not drive or operate machinery.

Side effects

Medicines and their possible side effects can affect individualpeople in different ways. The following are some of the side effects that areknown to be associated with this medicine. Because a side effect is statedhere, it does not mean that all people using this medicine will experience thator any side effect.

• Dry mouth, skin or eyes
• Blurred vision
• Disturbances of the gut, such as constipation, diarrhoea, nausea, indigestion, abdominal pain, flatulence, acid reflux
• Difficulty in passing urine
• Awareness of your heartbeat (palpitations)
• Swollen ankles (peripheral oedema)
• Headache
• Drowsiness
• Dizziness
• Confusion
• Difficulty sleeping (insomnia)
• Nervousness
• Sore mouth or tongue, mouth ulcers
• Chest pain
• Loss of appetite
• Thirst
• Pain in the muscles or joints
• Skin reactions such as rash or itching
• Increased blood flow to the skin on the face (facial flushing)
• Abnormal heart beats (arrhythmias)
• False perceptions of things that are not really there (hallucinations)

The side effects listed above may not include all of the sideeffects reported by the drug'smanufacturer.For moreinformation about any other possible risks associated with this medicine,please read the information provided with the medicine or consult your doctoror pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicinesyou are already taking, including those bought without a prescription andherbal medicines, before you start treatment with this medicine. Similarly,check with your doctor or pharmacist before taking any new medicines whiletaking this one, to ensure that thecombination is safe.

There may be an increased risk of side effects such as drymouth, blurred vision, drowsiness, constipation and difficulty passing urine,if this medicine is taken with other medicines that have anticholinergiceffects, such as the following:

• amantadine
• anticholinergic medicines for Parkinson's symptoms, eg procyclidine, orphenadrine, trihexiphenidyl (benzhexol)
• antihistamines, eg brompheniramine, chlorphenamine
• antipsychotic medicines, eg haloperidol, chlorpromazine, clozapine
• antispasmodic medicines, eg hyoscine, atropine
• disopyramide
• other anticholinergic medicines for urinary incontinence, eg tolterodine, solifenacin, propiverine
• MAOI antidepressants, eg phenelzine, tranylcypromine
• tricyclic antidepressants, eg amitriptyline, clomipramine.

This medicine may reduce the absorption of levodopa (used fortreating Parkinson's disease) from the gut.

This medicine may reduce the effects of the following medicineson the gut:

• cisapride
• domperidone
• metoclopramide.

This medicine may oppose the effects of medicines that havecholinergic effects, such as the following:

• donepezil, galantamine or rivastigmine used to treat Alzheimer's disease
• neostigmine
• distigmine
• pyridostigmine.

If you experience a dry mouth as a side effect of this medicineyou may find that medicines that are designed to dissolve and be absorbed fromunder the tongue, eg sublingual glyceryl trinitrate (GTN) tablets for angina,become less effective. This is because the tablets do not dissolve properly ina dry mouth. To resolve this, drink a mouthful of water before takingsublingual tablets.

Other medicines containing the same active ingredient

Oxybutynin tablets are also available without a brand name, ieas thegeneric medicine.