Oxybutynin, sold under the brand name Ditropan among others, is an

anticholinergic Anticholinergics (anticholinergic agents) are substances that block the action of the acetylcholine (ACh) neurotransmitter at synapses in the central nervous system, central and peripheral nervous system. These agents inhibit the parasympatheti ...

medication primarily used to treat

overactive bladder Overactive bladder (OAB) is a common condition where there is a frequent feeling of needing to urinate to a degree that it negatively affects a person's life. The frequent need to urinate may occur during the day, at night, or both. Loss of bl ...

. It is widely considered a

first-line therapy A therapy or medical treatment is the attempted remediation of a health problem, usually following a medical diagnosis. Both words, ''treatment'' and ''therapy'', are often abbreviated tx, Tx, or Tx. As a rule, each therapy has indications an ...

for overactive bladder due to its well-studied side effect profile, broad applicability, and continued efficacy over long periods of time. It works similar to

tolterodine Tolterodine, sold under the brand name Detrol among others, is a medication used to treat frequent urination, urinary incontinence, or urinary urgency. Effects are seen within an hour. It is taken by mouth. Common side effects include head ...

darifenacin Darifenacin (trade name Enablex in United States and Canada, Emselex in the European Union) is a medication used to treat urinary incontinence due to an overactive bladder. It was discovered by scientists at the Pfizer research site in Sandwich, ...

, and

solifenacin Solifenacin, sold as the brand name Vesicare among others, is a medicine used to treat overactive bladder and neurogenic detrusor overactivity (NDO). It may help with incontinence, urinary frequency, and urinary urgency. Benefits appear simi ...

, although it is usually preferred over these medications. It is sometimes used

off-label Off-label use is the use of pharmaceutical drugs for an unapproved indication (medicine), indication or in an unapproved age group, dose (biochemistry), dosage, or route of administration. Both prescription drugs and over-the-counter drugs (OTCs) ca ...

for treatment of

hyperhidrosis Hyperhidrosis is a medical condition in which a person exhibits excessive perspiration, sweating, more than is required for the Thermoregulation, regulation of body temperature. Although it is primarily a physical burden, hyperhidrosis can deterio ...

, or excessive sweating. It has also been used off-label to treat

bedwetting Nocturnal enuresis (NE), also informally called bedwetting, is involuntary urination while asleep after the age at which bladder control usually begins. Bedwetting in children and adults can result in emotional stress. Complications can inclu ...

in children, but this use has declined, as it is most likely ineffective in this role. It is taken

by mouth Oral administration is a route of administration whereby a substance is taken through the Human mouth, mouth, swallowed, and then processed via the digestive system. This is a common route of administration for many medications. Oral administ ...

or applied to the skin. Common side effects include

dry mouth Xerostomia, also known as dry mouth, is a subjective complaint of dryness in the mouth, which may be associated with a change in the composition of saliva, reduced salivary flow, or have no identifiable cause. This symptom is very common and is o ...

constipation Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The Human feces, stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the ...

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to Balance disorder, disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a ...

trouble sleeping Insomnia, also known as sleeplessness, is a sleep disorder where people have difficulty sleeping. They may have difficulty falling asleep, or staying asleep for as long as desired. Insomnia is typically followed by daytime sleepiness, low ene ...

, and

urinary tract infections A urinary tract infection (UTI) is an infection that affects a part of the urinary tract. Lower urinary tract infections may involve the bladder (cystitis) or urethra ( urethritis) while upper urinary tract infections affect the kidney (pye ...

. Serious side effects may include

urinary retention Urinary retention is an inability to completely empty the bladder. Onset can be sudden or gradual. When of sudden onset, symptoms include an inability to urinate and lower abdominal pain. When of gradual onset, symptoms may include urinary incont ...

and an increased risk of

heat stroke Heat stroke or heatstroke, also known as sun-stroke, is a severe heat illness that results in a body temperature greater than , along with red skin, headache, dizziness, and confusion. Sweating is generally present in exertional heatstro ...

. Use in

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

appears safe but has not been well studied while use in

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

is of unclear safety. It is an

antimuscarinic A muscarinic acetylcholine receptor antagonist, also simply known as a muscarinic antagonist or as an antimuscarinic agent, is a type of anticholinergic drug that blocks the activity of the muscarinic acetylcholine receptors (mAChRs). The muscarin ...

and works by blocking the effects of

acetylcholine Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Par ...

smooth muscle Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non- striated, so-called bec ...

. Oxybutynin was approved for medical use in the US in 1975. It is available as a

generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ch ...

. In 2022, it was the 110th most commonly prescribed medication in the United States, with more than 5million prescriptions.

Medical use

Oxybutynin is used in the form of instant-release capsules,

extended-release Modified-release dosage is a mechanism that (in contrast to immediate-release dosage) delivers a drug with a delay after its administration (delayed-release dosage) or for a prolonged period of time (extended-release R, XR, XLdosage) or to a spe ...

capsules, or transdermal (

topical A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...

) products. All of these are considered safe and effective options for treatment of

detrusor muscle The detrusor muscle, also detrusor urinae muscle, muscularis propria of the urinary bladder and (less precise) muscularis propria, is smooth muscle found in the wall of the bladder. The detrusor muscle remains relaxed to allow the bladder to s ...

-mediated

. Extended-release formulations decrease the number of weekly incontinence episodes by an average of 90% compared to an untreated state. Some studies have identified advantages of transdermal oxybutynin over capsules, finding decreased frequency of incontinence episodes and increased average voided volume of urine. Oxybutynin and Tolterodine in treating overactive bladder

Oxybutynin and Tolterodine in treating overactive bladder

Oxybutynin has been established through head-to-head trials as a more effective for overactive bladder than

, another anticholinergic medication. Specifically, the extended-release form of oxybutynin was found to have greater effect in both the short- and long-term. However, oxybutynin is not selective for the bladder like tolterodine, and thus has a wider range of side effects. Tolterodine and other anticholinergics are primarily used when clinicians and patients want to reduce the side effect profile. Because both drugs have been studied extensively and shown relatively high efficacy, both oxybutynin and tolterodine are considered first-line treatments for overactive bladder. They are thus the typical choices for initial treatment of the condition. The choice of initial therapy often comes down to whether a patient prefers somewhat higher efficacy (oxybutynin) or somewhat reduced side effects (tolterodine).

Hyperhidrosis

Since the 2010s, oxybutynin has increasingly been used to treat

(excessive sweating). Numerous studies have identified concrete benefits of the drug in treating this condition, but have not identified appropriate

dosing Dosing generally applies to feeding chemicals or medicines when used in small quantities. For medicines the term ''dose (biochemistry), dose'' is generally used. In the case of inanimate objects the word dosing is typical. The term dose titratio ...

or the full spectrum of possible

side effects In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually used ...

, although

is seemingly infrequent in patients with hyperhidrosis. Until further clinical trials can be conducted, oxybutynin is only used as an off-label medication for hyperhidrosis (as of 2024).

Adverse effects

Common adverse effects that are associated with oxybutynin and other

anticholinergics Anticholinergics (anticholinergic agents) are substances that block the action of the acetylcholine (ACh) neurotransmitter at synapses in the central and peripheral nervous system. These agents inhibit the parasympathetic nervous system by sel ...

include:

, difficulty in urination,

blurred vision Blurred vision is an ocular symptom where vision becomes less precise and there is added difficulty to resolve fine details. Temporary blurred vision may involve dry eyes, eye infections, alcohol poisoning, hypoglycemia, or low blood pressur ...

drowsiness Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep ...

, and

. Anticholinergics have also been known to induce

delirium Delirium (formerly acute confusional state, an ambiguous term that is now discouraged) is a specific state of acute confusion attributable to the direct physiological consequence of a medical condition, effects of a psychoactive substance, or ...

. Oxybutynin's tendency to reduce sweating can be dangerous. Reduced sweating increases the risk of

heat exhaustion Heat exhaustion is a heat-related illness characterized by the body's inability to effectively cool itself, typically occurring in high ambient temperatures or during intense physical exertion. In heat exhaustion, core body temperature ranges from ...

and

in apparently safe situations where normal sweating keeps others safe and comfortable. Adverse effects of elevated body temperature are more likely for the elderly and for those with health issues, especially

multiple sclerosis Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...

. ''N''-Desethyloxybutynin is an

active metabolite An active metabolite, or pharmacologically active metabolite is a biologically active metabolite of a xenobiotic substance, such as a drug or environmental chemical. Active metabolites may produce therapeutic effects, as well as harmful effects. ...

of oxybutynin that is thought responsible for much of the adverse effects associated with the use of oxybutynin. ''N''-Desethyloxybutynin plasma levels may reach as much as six times that of the parent drug after administration of the immediate-release oral formulation. Alternative dosage forms have been developed in an effort to reduce blood levels of ''N''-desethyloxybutynin and achieve a steadier concentration of oxybutynin than is possible with the instant-release form. The long-acting formulations also allow once-daily administration instead of the twice-daily dosage required with the immediate-release form. The transdermal patch, in addition to the benefits of the extended-release oral formulations, bypasses the first-pass hepatic effect that the oral formulations are subject to.

Contraindications

Oxybutynin chloride is contraindicated in patients with untreated narrow angle

glaucoma Glaucoma is a group of eye diseases that can lead to damage of the optic nerve. The optic nerve transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of ...

, and in patients with untreated narrow anterior chamber angles—since anticholinergic drugs may aggravate these conditions. It is also contraindicated in partial or complete obstruction of the gastrointestinal tract, hiatal hernia,

gastroesophageal reflux disease Gastroesophageal reflux disease (GERD) or gastro-oesophageal reflux disease (GORD) is a chronic upper gastrointestinal disease in which stomach content persistently and regularly flows up into the esophagus, resulting in symptoms and/or ...

, paralytic ileus, intestinal atony of the elderly or debilitated patient,

megacolon Megacolon is an abnormal dilation of the colon (anatomy), colon (also called the large intestine). This leads to hypertrophy of the colon. The dilation is often accompanied by a paralysis of the peristalsis, peristaltic movements of the bowel. In ...

toxic megacolon Toxic megacolon is an acute form of colonic distension. It is characterized by a very dilated Colon (anatomy), colon (megacolon), accompanied by abdominal distension (bloating), and sometimes fever, abdominal pain, or Shock (circulatory), shock. ...

complicating

ulcerative colitis Ulcerative colitis (UC) is one of the two types of inflammatory bowel disease (IBD), with the other type being Crohn's disease. It is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary sympto ...

, severe colitis, and

myasthenia gravis Myasthenia gravis (MG) is a long-term neuromuscular junction disease that leads to varying degrees of skeletal muscle weakness. The most commonly affected muscles are those of the eyes, face, and swallowing. It can result in double vision, ...

. It is contraindicated in patients with

obstructive uropathy Obstructive uropathy is a structural or functional hindrance of normal urine flow, sometimes leading to renal dysfunction (obstructive nephropathy). It is a very broad term, and does not imply a location or cause. Presentation Symptoms, less lik ...

and in patients with unstable cardiovascular status in acute hemorrhage. Oxybutynin chloride is contraindicated in patients who have demonstrated hypersensitivity to the product.

Pharmacology

Sources say the drug is absorbed within one hour and has an elimination half-life of 2 to 5 hours. There is a wide variation among individuals in the drug's concentration in blood. This, and its low concentration in urine, suggest that it is eliminated through the liver.

Chemistry

Oxybutynin contains one

stereocenter In stereochemistry, a stereocenter of a molecule is an atom (center), axis or plane that is the focus of stereoisomerism; that is, when having at least three different groups bound to the stereocenter, interchanging any two different groups cr ...

. Commercial formulations are sold as the

racemate In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as r ...

. The (''R'')-enantiomer is a more potent anticholinergic than either the racemate or the (''S'')-enantiomer, which is essentially without anticholinergic activity at doses used in clinical practice. However, (''R'')-oxybutynin administered alone offers little or no clinical benefit above and beyond the racemic mixture. The other actions (calcium antagonism, local anesthesia) of oxybutynin are not stereospecific. (''S'')-Oxybutynin has not been clinically tested for its spasmolytic effects, but may be clinically useful for the same indications as the racemate, without the unpleasant anticholinergic side effects.

Society and culture

Brand names

Oxybutynin is available by mouth in generic formulation and under the brand names Ditropan, Lyrinel XL, Ditrospam, Kentera, and Aquiette, as a transdermal patch under the brand name Oxytrol, and as a

topical gel Topical gels are a topical drug delivery dosage form commonly used in cosmetics and treatments for skin diseases because of their advantages over cream and ointment. They are formed from a mixture of gelator, solvent, active drug, and other excipie ...

under the brand name Gelnique.

Research

A large study linked the development of dementia in those over 65 to the use of oxybutynin, due to its

properties.

References

{{Authority control Alkyne derivatives Carboxylate esters Cyclohexyl compounds Diethylamino compounds Drugs developed by AbbVie Drugs developed by Johnson & Johnson M1 receptor antagonists M2 receptor antagonists M3 receptor antagonists M4 receptor antagonists M5 receptor antagonists Tertiary alcohols Wikipedia medicine articles ready to translate