- Approval Id
- bd9ef9f0869170b4
- Drug Approval Emc Name
- Oxybutynin Hydrochloride 2.5mg Tablets
- Drug Name
- Oxybutynin Hydrochloride 2.5mg Tablets
- Company Name
- Tillomed Laboratories Ltd
- Company Address
- 220 Butterfield, Great Marlings, Luton, LU2 8DL, UK
- Company Website
- http://www.tillomed.com/
- Company Telephone
- +44 (0)1480 402 400
- Company Medical Info Direct Line
- +44 (0)1480 402 400 [option 2]
- Company Medical Info Email
- Medical.Information@Tillomed.com
- Company Customer Care Direct Line
- +44 (0)1480 402 400 [option 1]
- Company Stock Availability
- +44 (0)1480 402 400 [option 1]
- Atc Code
- G04BD
- Legal Category
- Prescription only medicine
- Authorisation Holder
- Tillomed Laboratories Ltd
220 Butterfield
Great Marlings
Luton
LU2 8DL
United Kingdom
- Authorisation Number
- PL 11311/0136
- Authorisation Date
- 10 February 1999 / 27/03/2009
- Instruction Authorisation Holder
- Tillomed Laboratories Ltd
220 Butterfield
Great Marlings
Luton
LU2 8DL
United Kingdom
- Instruction Authorisation Number
- PL 11311/0136
- Instruction Authorisation Date
- 10 February 1999 / 27/03/2009
- Instruction Composition
- Each tablet contains 2.5 mg of oxybutynin hydrochloride.
Excipients with known effect: Each tablet contains 59.45mg of lactose (as lactose monohydrate).
For the full list of excipients, see section 6.1
- Instruction Dosage Form
- Tablet
Light blue, circular flat bevelled edged tablet with an approximate diameter of 6 mm, marked OXB 2.5 on one side and a break line on reverse.
The score line is only to facilitate breaking for ease of swallowing and not to divide into equal doses.
- Instruction Clinical Particulars
- 4.1 Therapeutic indications
Oxybutynin hydrochloride has antispasmodic/anticholinergic actions.
It is indicated for:
\*\*Adults:\*\*
The symptomatic treatment of urinary incontinence, frequency and urgency in patients with an unstable bladder (urge syndrome), whether due to neurogenic bladder disorders (detrusor hyperreflexia) in conditions such as multiple sclerosis and spina bifida, or to idiopathic detrusor instability (motor urge incontinence).
\*\*Paediatric population\*\*
Oxybutynin hydrochloride is indicated in children over 5 years of age for:
- Urinary incontinence, urgency and frequency in unstable bladder conditions due to idiopathic overactive bladder or neurogenic bladder disorders (detrusor overactivity).
- Nocturnal enuresis associated with detrusor over activity, in conjunction with non-drug therapy, when other treatment has failed.4.2 Posology and method of administration
\*\*Posology\*\*
The dosage should be determined individually.
\*\*\*Adults\*\*\*
The usual dose is 5 mg two or three times a day. This may be increased up to a maximum of 5 mg four times daily (maximum dose 20 mg Oxybutynin per day) to obtain a clinical response, provided that the side effects are tolerated.
\*\*\*Elderly\*\*\*
The elimination half-life is increased in the elderly. Therefore, a dose of 2.5 mg twice daily, particularly if the patient is frail, is likely to be adequate. This dose may be increased to 5 mg two times a day to obtain a clinical response provided the side effects are well tolerated.
\*\*\*Paediatric population\*\*\*
\*Children 5 years of age and over\*
\*Neurogenic bladder instability\*: the usual dose is 2.5 mg twice a day. This dose can be increased up to 5 mg two or three times daily to obtain a clinical response provided the side effects are well tolerated.
\*Nocturnal enuresis\*: the usual dose is 2.5 mg twice a day. This dose may be increased to 5 mg two or three times daily to obtain a clinical response provided the side effects are tolerated. The last dose should be given before bedtime.
\*Children under 5 years of age\*
Oxybutynin is not recommended in children under 5 years of age due to insufficient clinical data.
\*\*\*\*Method of administration\*\*\*\*
For oral use.
The tablet should be swallowed with a glass of water.4.3 Contraindications
o Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
o Myasthenia Gravis;
o Narrow angle glaucoma or shallow anterior chamber;
o Gastrointestinal obstructive disorders including paralytic ileus, intestinal atony.
o Toxic megacolon;
o Severe ulcerative colitis;
o Bladder outflow obstruction where urinary retention may be precipitated.4.4 Special warnings and precautions for use
Oxybutynin should be used with caution in patients with Parkinson's disease who are at greater risk of occurrence of adverse reactions to the product and in patients with autonomic neuropathy (such as those with Parkinson's disease), severe gastro-intestinal motility disorders, hepatic or renal impairment.
Anticholinergic medicinal products may decrease gastrointestinal motility and should be used with caution in patients with gastrointestinal obstructive disorders, intestinal atony and ulcerative colitis.
Oxybutynin may aggravate cognitive disorders, symptoms of prostatic hypertrophy and tachycardia (thus be cautious in case of hyperthyroidism, congestive heart failure, cardiac arrhythmia, coronary heart disease, hypertension).
Anticholinergic CNS effects (such as hallucinations, agitation, confusion, somnolence) have been reported. Monitoring is recommended, especially in the first few months after initiating therapy or increasing the dose. If anticholinergic CNS effects develop, termination of treatment or dose reduction may be considered.
Since oxybutynin can cause narrow-angle glaucoma, patients should be advised to contact a physician immediately if they are aware of a sudden loss of visual acuity or ocular pain.
Oxybutynin may reduce salivary secretions which could result in dental caries, parodontosis or oral candidiasis.
Anticholinergic medicinal products should be used with caution in patients who have hiatus hernia/gastro-oesophageal reflux and/or who are concurrently taking medicinal products (such as bisphosphonates) that can cause or exacerbate oesophagitis.
When Oxybutynin is used in high environmental temperatures, this can cause heat prostration due to decreased sweating.
\*\*Elderly\*\*
Anticholinergic medicinal products should be used with caution in elderly patients due to the risk of cognitive impairment. They also have a higher risk of occurrence of adverse reactions to the product.
\*\*Paediatric population\*\*
The use of Oxybutynin in children under 5 years of age is not recommended; it has not been established whether Oxybutynin can be safely used in this age group.
There is limited evidence supporting the use of Oxybutynin in children with monosymptomatic nocturnal enuresis (not related to detrusor overactivity).
In children over 5 years of age, Oxybutynin hydrochloride should be used with caution as they may be more sensitive to the effects of the product, particularly the CNS and psychiatric adverse reactions.
\*\*Excipients\*\*
This medicinal product contains lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.4.5 Interaction with other medicinal products and other forms of interaction
Care should be taken if other anticholinergic agents are administered together with oxybutynin hydrochloride, as potentiation of anticholinergic effects could occur.
The anticholinergic activity of oxybutynin is increased by concurrent use of other anticholinergics or medicinal products with anticholinergic activity, such as amantadine and other anticholinergic antiparkinsonian medicinal products (e.g. biperiden, levodopa), antihistamines, antipsychotics (e.g. phenothiazines, butyrophenones, clozapine), quinidine, digitalis, tricyclic antidepressants, atropine and related compounds like atropinic antispasmodics and dipyridamole.
By reducing gastric motility, oxybutynin may affect the absorption of other drugs.
Oxybutynin is metabolised by cytochrome P 450 isoenzyme CYP 3A4. Concomitant administration with a CYP3A4 inhibitor can inhibit oxybutynin metabolism and increase oxybutynin exposure.
Oxybutynin, as an anticholinergic agent, may antagonize the effect of prokinetic therapies.
Concomitant use with cholinesterase inhibitors may result in reduced cholinesterase inhibitor efficacy.
Patients should be informed that alcohol may enhance the drowsiness caused by anticholinergic agents such as oxybutynin (see section 4.7).4.6 Fertility, pregnancy and lactation
\*\*\*Pregnancy\*\*\*
There are no adequate data from the use of oxybutynin in pregnant women. Animal studies are insufficient with respect to effects on pregnancy, embryonal/foetal development, parturition or postnatal development (see section 5.3). The potential risk for humans is unknown. Oxybutynin should not be used during pregnancy unless clearly necessary.
\*\*\*Breastfeeding\*\*\*
When oxybutynin is used during lactation, a small amount is excreted in breast milk. Use of oxybutynin during breast-feeding is therefore not recommended.4.7 Effects on ability to drive and use machines
Oxybutynin may cause drowsiness or blurred vision. Patients should be cautioned regarding activities requiring mental alertness such as driving, operating machinery or performing hazardous work whilst taking this medicine.4.8 Undesirable effects
Like all medicines, oxybutynin can cause undesirable effects, although not everybody gets them. The frequency of possible undesirable effects listed below are currently defined as:
Very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1,000 to <1/100); rare (≥1/10,000 to <1/1,000); very rare (<1/10,000), not known (cannot be estimated from the available data).
| | | |
| --- | --- | --- |
| \*\*ADVERSE REACTIONS REPORTED\*\* | | |
| \*\*System Organ Class\*\* | \*\*Frequency\*\* | \*\*Adverse Reaction (MedDRA Terms)\*\* |
| \*Infections and Infestations\* | Not known | urinary tract infection |
| \*Immune System Disorders\* | Not known | hypersensitivity |
| \*Psychiatric Disorders\* | Common | confusional state |
| Not known | agitation, anxiety, cognitive disorders in elderly, hallucinations, nightmares, paranoia, symptoms of depression, dependence to oxybutynin (in patients with history of drug or substance abuse) |
| \*Nervous System Disorders\* | Very common | dizziness, headache, somnolence |
| Not known | cognitive disorders, convulsions, drowsiness, disorientation |
| \*Eye Disorders\* | Very common | vision blurred |
| Common | dry eyes |
| Not known | angle closure glaucoma, increased intraocular pressure, mydriasis |
| \*Cardiac Disorders\* | Common | palpitation |
| Not known | arrhythmia, tachycardia |
| \*Vascular Disorders\* | Common | flushing (which may be more marked in children) |
| \*Respiratory, thoracic, and mediastinal disorders\* | Not known | epistaxis |
| \*Gastrointestinal Disorders\* | Very common | constipation, dry mouth, nausea |
| Common | diarrhoea, vomiting |
| Uncommon | abdominal discomfort, anorexia, decreased appetite, dysphagia |
| Not known | gastroesophageal reflux, pseudo-obstruction in patients at risk (elderly or patients with constipation and treated with other drugs that decrease intestinal motility) |
| \*Skin and Subcutaneous Tissue Disorders\* | Very common | dry skin |
| Not known | angioedema, hypohidrosis, rash, urticaria, photosensitivity |
| \*Musculoskeletal and connective tissue disorders\* | Not known | muscle disorders manifested as muscle weakness, myalgia and/ or muscle spasms |
| \*Renal and Urinary Disorders\* | Common | urinary retention |
| Not known | difficulty in micturition |
| \*Injury, Poisoning and Procedural Complications\* | Not known | heat stroke |
\*\*Reporting of suspected adverse reactions\*\*
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.4.9 Overdose
\*\*Symptoms of intoxication\*\*
The symptoms of overdose with oxybutynin progress from an intensification of the usual side-effects of CNS disturbances (from restlessness and excitement to psychotic behaviour), circulatory changes (flushing, fall in blood pressure, circulatory failure etc.), respiratory failure, paralysis and coma.
\*\*Management\*\*
\*\*Measures to be taken are\*\*:
1. Immediate gastric lavage
2. Physostigmine by slow intravenous injection
\*\*Adults:\*\* 0.5 to 2.0 mg of physostigmine by slow intravenous administration. Repeat after 5 minutes, if necessary up to a maximum total dose of 5mg.
\*\*Paediatric population:\*\* 30 micrograms/kg of physostigmine by slow intravenous administration. Repeat after 5 minutes, if necessary up to a maximum total dose of 2 mg.
Fever should be treated symptomatically with tepid sponging or ice packs.
In pronounced restlessness or excitation, diazepam 10 mg may be given by intravenous injection.
Tachycardia may be treated by intravenous injection of propranolol and urinary retention can be managed by bladder catheterisation.
In the event of progression of the curare-like effect to the paralysis of the respiratory muscles, mechanical ventilation will be required.
- Instruction Pharmacology
- 5.1 Pharmacodynamic properties
Pharmacotherapeutic Group: Urinary Antispasmodics
\*ATC-Code:\* G04BD
\*\*Mechanism of action\*\*
Oxybutynin has both direct antispasmodic action on the smooth muscle of the bladder detrusor muscle as well as an anticholinergic action in blocking the muscarinic effects of acetylcholine on smooth muscle.
These properties cause relaxation of the detrusor muscle of the bladder and in patients with an unstable bladder. Oxybutynin increases bladder capacity and reduces the incidence of spontaneous contraction of the detrusor muscle.5.2 Pharmacokinetic properties
\*\*Absorption\*\*
Oxybutynin is poorly absorbed from the gastro-intestinal tract, the peak plasma level is reached between 0.5 to 1 hour after administration.
\*\*Distribution\*\*
It is highly bound to plasma proteins.
\*\*Biotransformation\*\*
Oxybutynin undergoes extensive first-pass metabolism, particularly by the cytochrome P450 isoenzyme CYP3A4, and systemic oral bioavailability has been reported to be only 6%. N-desethyloxybutynin is an active metabolite.
\*\*Elimination\*\*
The half-life is biexponential, the first phase being about 40 minutes and the second about 2 – 3 hours. Oxybutynin and its metabolites are excreted in the faeces and urine. There is no evidence of accumulation. The elimination half-life maybe increased in the elderly, particularly if they are frail.5.3 Preclinical safety data
No data of therapeutic relevance.
- Instruction Pharmaceutical Particulars
- 6.1 List of excipients
Crospovidone, microcrystalline cellulose, lactose monohydrate, magnesium stearate, indigo carmine aluminium lake (E132).6.2 Incompatibilities
None known.6.3 Shelf life
3 years.6.4 Special precautions for storage
Store below 25°C in a dry place.6.5 Nature and contents of container
Oxybutynin hydrochloride tablets are available in Aluminium / uPVC / PVdC strips in boxes of 20, 28, 30, 56, 60, 84 and 120 tablets.
Not all packs sizes may be marketed.6.6 Special precautions for disposal and other handling
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
- Instruction Content
- ## Composition
Each tablet contains 2.5 mg of oxybutynin hydrochloride.
Excipients with known effect: Each tablet contains 59.45mg of lactose (as lactose monohydrate).
For the full list of excipients, see section 6.1
## Pharmaceutical Form
Tablet
Light blue, circular flat bevelled edged tablet with an approximate diameter of 6 mm, marked OXB 2.5 on one side and a break line on reverse.
The score line is only to facilitate breaking for ease of swallowing and not to divide into equal doses.
## Clinical Particulars
4.1 Therapeutic indications
Oxybutynin hydrochloride has antispasmodic/anticholinergic actions.
It is indicated for:
\*\*Adults:\*\*
The symptomatic treatment of urinary incontinence, frequency and urgency in patients with an unstable bladder (urge syndrome), whether due to neurogenic bladder disorders (detrusor hyperreflexia) in conditions such as multiple sclerosis and spina bifida, or to idiopathic detrusor instability (motor urge incontinence).
\*\*Paediatric population\*\*
Oxybutynin hydrochloride is indicated in children over 5 years of age for:
- Urinary incontinence, urgency and frequency in unstable bladder conditions due to idiopathic overactive bladder or neurogenic bladder disorders (detrusor overactivity).
- Nocturnal enuresis associated with detrusor over activity, in conjunction with non-drug therapy, when other treatment has failed.4.2 Posology and method of administration
\*\*Posology\*\*
The dosage should be determined individually.
\*\*\*Adults\*\*\*
The usual dose is 5 mg two or three times a day. This may be increased up to a maximum of 5 mg four times daily (maximum dose 20 mg Oxybutynin per day) to obtain a clinical response, provided that the side effects are tolerated.
\*\*\*Elderly\*\*\*
The elimination half-life is increased in the elderly. Therefore, a dose of 2.5 mg twice daily, particularly if the patient is frail, is likely to be adequate. This dose may be increased to 5 mg two times a day to obtain a clinical response provided the side effects are well tolerated.
\*\*\*Paediatric population\*\*\*
\*Children 5 years of age and over\*
\*Neurogenic bladder instability\*: the usual dose is 2.5 mg twice a day. This dose can be increased up to 5 mg two or three times daily to obtain a clinical response provided the side effects are well tolerated.
\*Nocturnal enuresis\*: the usual dose is 2.5 mg twice a day. This dose may be increased to 5 mg two or three times daily to obtain a clinical response provided the side effects are tolerated. The last dose should be given before bedtime.
\*Children under 5 years of age\*
Oxybutynin is not recommended in children under 5 years of age due to insufficient clinical data.
\*\*\*\*Method of administration\*\*\*\*
For oral use.
The tablet should be swallowed with a glass of water.4.3 Contraindications
o Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
o Myasthenia Gravis;
o Narrow angle glaucoma or shallow anterior chamber;
o Gastrointestinal obstructive disorders including paralytic ileus, intestinal atony.
o Toxic megacolon;
o Severe ulcerative colitis;
o Bladder outflow obstruction where urinary retention may be precipitated.4.4 Special warnings and precautions for use
Oxybutynin should be used with caution in patients with Parkinson's disease who are at greater risk of occurrence of adverse reactions to the product and in patients with autonomic neuropathy (such as those with Parkinson's disease), severe gastro-intestinal motility disorders, hepatic or renal impairment.
Anticholinergic medicinal products may decrease gastrointestinal motility and should be used with caution in patients with gastrointestinal obstructive disorders, intestinal atony and ulcerative colitis.
Oxybutynin may aggravate cognitive disorders, symptoms of prostatic hypertrophy and tachycardia (thus be cautious in case of hyperthyroidism, congestive heart failure, cardiac arrhythmia, coronary heart disease, hypertension).
Anticholinergic CNS effects (such as hallucinations, agitation, confusion, somnolence) have been reported. Monitoring is recommended, especially in the first few months after initiating therapy or increasing the dose. If anticholinergic CNS effects develop, termination of treatment or dose reduction may be considered.
Since oxybutynin can cause narrow-angle glaucoma, patients should be advised to contact a physician immediately if they are aware of a sudden loss of visual acuity or ocular pain.
Oxybutynin may reduce salivary secretions which could result in dental caries, parodontosis or oral candidiasis.
Anticholinergic medicinal products should be used with caution in patients who have hiatus hernia/gastro-oesophageal reflux and/or who are concurrently taking medicinal products (such as bisphosphonates) that can cause or exacerbate oesophagitis.
When Oxybutynin is used in high environmental temperatures, this can cause heat prostration due to decreased sweating.
\*\*Elderly\*\*
Anticholinergic medicinal products should be used with caution in elderly patients due to the risk of cognitive impairment. They also have a higher risk of occurrence of adverse reactions to the product.
\*\*Paediatric population\*\*
The use of Oxybutynin in children under 5 years of age is not recommended; it has not been established whether Oxybutynin can be safely used in this age group.
There is limited evidence supporting the use of Oxybutynin in children with monosymptomatic nocturnal enuresis (not related to detrusor overactivity).
In children over 5 years of age, Oxybutynin hydrochloride should be used with caution as they may be more sensitive to the effects of the product, particularly the CNS and psychiatric adverse reactions.
\*\*Excipients\*\*
This medicinal product contains lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.4.5 Interaction with other medicinal products and other forms of interaction
Care should be taken if other anticholinergic agents are administered together with oxybutynin hydrochloride, as potentiation of anticholinergic effects could occur.
The anticholinergic activity of oxybutynin is increased by concurrent use of other anticholinergics or medicinal products with anticholinergic activity, such as amantadine and other anticholinergic antiparkinsonian medicinal products (e.g. biperiden, levodopa), antihistamines, antipsychotics (e.g. phenothiazines, butyrophenones, clozapine), quinidine, digitalis, tricyclic antidepressants, atropine and related compounds like atropinic antispasmodics and dipyridamole.
By reducing gastric motility, oxybutynin may affect the absorption of other drugs.
Oxybutynin is metabolised by cytochrome P 450 isoenzyme CYP 3A4. Concomitant administration with a CYP3A4 inhibitor can inhibit oxybutynin metabolism and increase oxybutynin exposure.
Oxybutynin, as an anticholinergic agent, may antagonize the effect of prokinetic therapies.
Concomitant use with cholinesterase inhibitors may result in reduced cholinesterase inhibitor efficacy.
Patients should be informed that alcohol may enhance the drowsiness caused by anticholinergic agents such as oxybutynin (see section 4.7).4.6 Fertility, pregnancy and lactation
\*\*\*Pregnancy\*\*\*
There are no adequate data from the use of oxybutynin in pregnant women. Animal studies are insufficient with respect to effects on pregnancy, embryonal/foetal development, parturition or postnatal development (see section 5.3). The potential risk for humans is unknown. Oxybutynin should not be used during pregnancy unless clearly necessary.
\*\*\*Breastfeeding\*\*\*
When oxybutynin is used during lactation, a small amount is excreted in breast milk. Use of oxybutynin during breast-feeding is therefore not recommended.4.7 Effects on ability to drive and use machines
Oxybutynin may cause drowsiness or blurred vision. Patients should be cautioned regarding activities requiring mental alertness such as driving, operating machinery or performing hazardous work whilst taking this medicine.4.8 Undesirable effects
Like all medicines, oxybutynin can cause undesirable effects, although not everybody gets them. The frequency of possible undesirable effects listed below are currently defined as:
Very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1,000 to <1/100); rare (≥1/10,000 to <1/1,000); very rare (<1/10,000), not known (cannot be estimated from the available data).
| | | |
| --- | --- | --- |
| \*\*ADVERSE REACTIONS REPORTED\*\* | | |
| \*\*System Organ Class\*\* | \*\*Frequency\*\* | \*\*Adverse Reaction (MedDRA Terms)\*\* |
| \*Infections and Infestations\* | Not known | urinary tract infection |
| \*Immune System Disorders\* | Not known | hypersensitivity |
| \*Psychiatric Disorders\* | Common | confusional state |
| Not known | agitation, anxiety, cognitive disorders in elderly, hallucinations, nightmares, paranoia, symptoms of depression, dependence to oxybutynin (in patients with history of drug or substance abuse) |
| \*Nervous System Disorders\* | Very common | dizziness, headache, somnolence |
| Not known | cognitive disorders, convulsions, drowsiness, disorientation |
| \*Eye Disorders\* | Very common | vision blurred |
| Common | dry eyes |
| Not known | angle closure glaucoma, increased intraocular pressure, mydriasis |
| \*Cardiac Disorders\* | Common | palpitation |
| Not known | arrhythmia, tachycardia |
| \*Vascular Disorders\* | Common | flushing (which may be more marked in children) |
| \*Respiratory, thoracic, and mediastinal disorders\* | Not known | epistaxis |
| \*Gastrointestinal Disorders\* | Very common | constipation, dry mouth, nausea |
| Common | diarrhoea, vomiting |
| Uncommon | abdominal discomfort, anorexia, decreased appetite, dysphagia |
| Not known | gastroesophageal reflux, pseudo-obstruction in patients at risk (elderly or patients with constipation and treated with other drugs that decrease intestinal motility) |
| \*Skin and Subcutaneous Tissue Disorders\* | Very common | dry skin |
| Not known | angioedema, hypohidrosis, rash, urticaria, photosensitivity |
| \*Musculoskeletal and connective tissue disorders\* | Not known | muscle disorders manifested as muscle weakness, myalgia and/ or muscle spasms |
| \*Renal and Urinary Disorders\* | Common | urinary retention |
| Not known | difficulty in micturition |
| \*Injury, Poisoning and Procedural Complications\* | Not known | heat stroke |
\*\*Reporting of suspected adverse reactions\*\*
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.4.9 Overdose
\*\*Symptoms of intoxication\*\*
The symptoms of overdose with oxybutynin progress from an intensification of the usual side-effects of CNS disturbances (from restlessness and excitement to psychotic behaviour), circulatory changes (flushing, fall in blood pressure, circulatory failure etc.), respiratory failure, paralysis and coma.
\*\*Management\*\*
\*\*Measures to be taken are\*\*:
1. Immediate gastric lavage
2. Physostigmine by slow intravenous injection
\*\*Adults:\*\* 0.5 to 2.0 mg of physostigmine by slow intravenous administration. Repeat after 5 minutes, if necessary up to a maximum total dose of 5mg.
\*\*Paediatric population:\*\* 30 micrograms/kg of physostigmine by slow intravenous administration. Repeat after 5 minutes, if necessary up to a maximum total dose of 2 mg.
Fever should be treated symptomatically with tepid sponging or ice packs.
In pronounced restlessness or excitation, diazepam 10 mg may be given by intravenous injection.
Tachycardia may be treated by intravenous injection of propranolol and urinary retention can be managed by bladder catheterisation.
In the event of progression of the curare-like effect to the paralysis of the respiratory muscles, mechanical ventilation will be required.
## Pharmacological Properties
5.1 Pharmacodynamic properties
Pharmacotherapeutic Group: Urinary Antispasmodics
\*ATC-Code:\* G04BD
\*\*Mechanism of action\*\*
Oxybutynin has both direct antispasmodic action on the smooth muscle of the bladder detrusor muscle as well as an anticholinergic action in blocking the muscarinic effects of acetylcholine on smooth muscle.
These properties cause relaxation of the detrusor muscle of the bladder and in patients with an unstable bladder. Oxybutynin increases bladder capacity and reduces the incidence of spontaneous contraction of the detrusor muscle.5.2 Pharmacokinetic properties
\*\*Absorption\*\*
Oxybutynin is poorly absorbed from the gastro-intestinal tract, the peak plasma level is reached between 0.5 to 1 hour after administration.
\*\*Distribution\*\*
It is highly bound to plasma proteins.
\*\*Biotransformation\*\*
Oxybutynin undergoes extensive first-pass metabolism, particularly by the cytochrome P450 isoenzyme CYP3A4, and systemic oral bioavailability has been reported to be only 6%. N-desethyloxybutynin is an active metabolite.
\*\*Elimination\*\*
The half-life is biexponential, the first phase being about 40 minutes and the second about 2 – 3 hours. Oxybutynin and its metabolites are excreted in the faeces and urine. There is no evidence of accumulation. The elimination half-life maybe increased in the elderly, particularly if they are frail.5.3 Preclinical safety data
No data of therapeutic relevance.
## Pharmaceutical Particulars
6.1 List of excipients
Crospovidone, microcrystalline cellulose, lactose monohydrate, magnesium stearate, indigo carmine aluminium lake (E132).6.2 Incompatibilities
None known.6.3 Shelf life
3 years.6.4 Special precautions for storage
Store below 25°C in a dry place.6.5 Nature and contents of container
Oxybutynin hydrochloride tablets are available in Aluminium / uPVC / PVdC strips in boxes of 20, 28, 30, 56, 60, 84 and 120 tablets.
Not all packs sizes may be marketed.6.6 Special precautions for disposal and other handling
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
