Regurin tablets and Regurin XL prolonged release capsules both contain the active ingredient trospium chloride, which is a type of medicine called an anticholinergic (or antimuscarinic) muscle relaxant. It works by relaxing the involuntary muscle that is found in the wall of the bladder.

What is it used for?

  • Increased need to pass urine (urinary frequency), uncontrollable urges to pass urine (urinary urgency) and involuntary leakage of urine (urinary incontinence)due to an overactive bladder.

How does it work?

  • Regurin tablets and Regurin XL prolonged release capsules both contain the active ingredient trospium chloride, which is a type of medicine called an anticholinergic (or antimuscarinic) muscle relaxant. It works by relaxing the involuntary muscle that is found in the wall of the bladder.
  • The muscle in the wall of the bladder is called the detrusor muscle. It can sometimes contract in uncontrollable spasms, and this is often referred to as having an overactive bladder.
The overactive detrusor muscle can increase in the number of times you need to pass urine, or cause uncontrollable urges to pass urine, or involuntary leakage of urine (urinary incontinence).
  • Trospium works by relaxing the detrusor muscle in the wall of the bladder. It does this by blocking receptors called cholinergic (or muscarinic) receptors that are found on the surface of the muscle cells. This prevents a natural body chemical called acetylcholine from acting on these receptors.
  • Normally when acetylcholine acts on these receptors, it causes the detrusor muscle to contract and the bladder to empty. By blocking acetylcholine, trospium helps the muscle in the bladder wall to relax. This reduces unstable, involuntary contractions of the bladder, and thereby increases the capacity of the bladder to hold urine. In turn, this reduces the need to pass urine.
  • Regurin tablets are known as an immediate release dose form. This means that the medicine is absorbed into the bloodstream from the gut soon after the tablets are taken. These tablets are taken twice a day.
  • Regurin XL capsules are known as prolonged release capsules. They are designed to release the medicine slowly over the day as the capsule passes through the gut. This means the capsule only need to be taken once a day. The capsules should be swallowed whole with liquid and not chewed or crushed, as this would stop their prolonged release action from working.
  • Warning!

    • This medicine may cause blurred vision and so may affect your ability to drive or operate machinery safely. Do not drive or operate machinery until you know how this medicine affects you.
    • Your doctor should reassess whether you still need treatment with this medicine every three to six months.

    Use with caution in

    • Obstruction or decreased motility of the stomach or intestines, such as pyloric stenosis.
    • Obstruction of the outflow of urine from the bladder.
    • Disorder of the involuntary nerves that control the internal organs (autonomic neuropathy).
    • Hiatus hernia associated with reflux oesophagitis.
    • Heart disease, for example angina, heart failure, irregular heart beats (arrhythmias).
    • Overactive thyroid gland (hyperthyroidism).
    • Decreased liver function.
    • Decreased kidney function.

    Not to be used in

    • Inability to pass urine (urinary retention).
    • Closed angle glaucoma.
    • Abnormal muscle weakness (myasthenia gravis).
    • 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).
    • Fast, abnormal heart rhythms (tachyarrhythmias).
    • People with lactose intolerance, glucose/galactose malabsorption or a genetic disorder leading to accumulation of galactose in the blood (galactosaemia). (Regurin tablets contain lactose).
    • People who suffer from an allergy to wheat. (Regurin tablets contain wheat starch).
    • People with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption, or sucrose-isomaltase insufficiency. (Regurin tablets and Regurin XL capsules both contain sucrose.)
    • There is insufficient information regarding the safety and efficacy of this medicine in children. Regurin tablets are not recommended for children under 12 years old. Regurin XL capsules are not recommended for children under 18 years old.
    • This medicine should not be used if you are allergic to one of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

    If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

    Pregnancy and breastfeeding

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

    • The safety of this medicine in pregnancy has not been established. It should therefore be used with caution during pregnancy, and only if the benefits to the mother outweigh any risks to the foetus. Seek medical advice from your doctor.
    • It is not known if this medicine passes into breast milk. It should be used with caution in nursing mothers, and only if the benefits to the mother outweigh any risks to the nursing infant. Discuss this with your doctor.

    Label warnings

    • Take this medication an hour before food or on an empty stomach.

    Side effects

    Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

    Very common 

    • Dry mouth.


    • Dry eyes and nose.
    • Indigestion (dyspepsia).
    • Abdominal pain and bloating.
    • Constipation.
    • Nausea.


    • Excess gas in the stomach and intestines (flatulence).


    • Difficulty in emptying the bladder.
    • Difficulty in passing urine (urinary retention).
    • Increased heart rate (tachycardia).
    • Visual disturbances, such as blurred vision, difficulty focusing on near objects.
    • Diarrhoea.
    • Difficulty in breathing (dyspnoea).
    • Rash.
    • Weakness or loss of strength (asthenia).
    • Chest pain.

    Very rare

    • Abnormal heart beats (arrhythmias).
    • Swelling of the legs and ankles due to excess fluid retention (peripheral oedema).
    • Headache.

    The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

    For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

    How can this medicine affect other medicines?

    It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, ask your doctor or pharmacist before taking any new medicines while taking this one, so they can check that the combination is safe.

    There may be an increased risk of side effects such as dry mouth, blurred vision, constipation and difficulty passing urine, if this medicine is taken with other medicines that have anticholinergic effects, 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.
    • If you experience a dry mouth as a side effect of this medicine you may find that medicines that are designed to dissolve and be absorbed from under the tongue, eg sublingual glyceryl trinitrate (GTN) tablets, become less effective. This is because the tablets do not dissolve properly in a dry mouth. To resolve this, drink a mouthful of water before taking sublingual tablets.

    This medicine may reduce the effects of the following medicines on the gut:

    • cisapride
    • domperidone
    • metoclopramide.

    Trospium may enhance the increased heart rate that may be experienced after taking beta-sympathomimetic medicines such as the following:

    • adrenaline
    • certain medicines for asthma, eg salbutamol, terbutaline, salmeterol
    • decongestant medicines, eg ephedrine, pseudoephedrine, phenylpropanolamine.

    The following medicines may reduce the absorption of trospium from the gut and should therefore not be taken at the same time of day as trospium:

    • guar gum
    • colestipol
    • colestyramine.