Oxybutynin Hydrochloride Tablets 2.5mg
SUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
Oxybutynin Hydrochloride Tablets 2.5mg.
2. QUALITATIVE AND QUANTITATIVE COMPOSITION
Each tablet contains 2.5mg Oxybutynin Hydrochloride USP.
3. PHARMACEUTICAL FORM
White uncoated tablets.
Tablet markings “OBC” one side and “2.5” on the other side.
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
Indicated for urinary incontinence, urgency and frequency in unstable bladder conditions due either to idiopathic detrusor instability or neurogenic bladder disorders (detrusor hyperreflexia) in conditions such as spina bifida and multiple sclerosis.
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 overactivity, in conjunction with nondrug therapy, when other treatment has failed.
4.2. Posology and Method of Administration
Posology
Adults: The usual dose is 5mg two or three times daily. This may be increased to a maximum dosage of 5mg four times daily (20mg) to obtain a satisfactory clinical response provided that the side-effects are tolerated.
Elderly: The elimination half-life may be increased in some elderly patients, therefore, dosage should be individually titrated commencing at 2.5mg twice daily. This dose may be titrated upwards to 5mg twice a day. The final dosage will depend on response and tolerance to side-effects. As with other anticholinergic drugs, caution should be observed in frail and elderly patients.
Children over 5 years of age: Neurogenic bladder disorders: The usual dose is 2.5mg twice daily. This may be increased to a maximum of 5mg three times daily to obtain a clinical response provided that the side-effects are tolerated.
Nocturnal enuresis: The usual dose is 2.5mg twice daily. This dose may be titrated upwards to 5mg two or three times a day. The last dose should be given before bedtime.
Children under 5 years of age: Not recommended.
Method of Administration: For oral administration.
4.3 Contra-Indications
Hypersensitivity to any of the ingredients in the formulation; patients with a significant degree of bladder outflow obstruction where precipitation of urinary retention may occur; myasthenia gravis; glaucoma (since it may raise intra-ocular pressure); patients with intestinal atony, severe ulcerative colitis, toxic megacolon and other functional or organic gastrointestinal obstructive disorders.
4.4. Special warnings and precautions for use
Oxybutynin should be used with caution in frail elderly and in patients with autonomic neuropathy, hepatic or renal disease.
The symptoms of hyperthyroidism, coronary artery disease, congestive heart failure, cardiac arrhythmias, tachycardias and prostatic hypertrophy may be aggravated following administration of oxybutynin.
Special care should be taken in patients with hiatus hernia associated with reflux oesophagitis, as anticholinergic drugs may aggravate this condition.
Paediatric population:
Oxybutynin hydrochloride is not recommended for use in children below age 5 years due to insufficient data on safety and efficacy.
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.
Patients with rare heriditary problems of galactose intolerance, the Lapp lactose deficiency or glucose-galactose malabsorption should not take this medicines.
4.5. Interactions with other Medicinal Products and other Forms of Interaction
Care should be taken if other anticholinergic agents are administered together with oxybutynin, as potentiation of anticholinergic effects can occur.
Occasional cases of interaction between anticholinergics and phenothiazines, amantadine, butyrophenones, levodopa, digitalis and tricyclic antidepressants have been reported and care should be taken if oxybutynin is administered concurrently with such drugs.
Oxybutynin by reducing gastrointestinal motility may affect absorption of other drugs.
4.6. Pregnancy and Lactation
There is no experience as to the safety of oxybutynin during pregnancy in humans. However, in foetal toxicity and fertility studies in animals, effects were seen on reproductive processes at dosages associated with maternal toxicity though this does not imply there are safety concerns in pregnancy. Oxybutynin should, therefore, only be prescribed during pregnancy if considered essential and there is no safer alternative.
Oxybutynin has been detected in breast milk, therefore oxybutynin should not be administered to women who are breast-feeding.
4.7. Effects on Ability to Drive and Use Machines
As oxybutynin may produce drowsiness and/or blurred vision, especially in association with alcohol, the patient should be cautioned regarding activities requiring mental alertness such as driving, operating machinery or performing hazardous work while taking this drug.
4.8. Undesirable Effects
The most frequently reported side-effects (> 1%) to oxybutynin are abdominal discomfort, blurred vision, constipation, dry mouth (about 22%), facial flushing, difficulty in micturition and nausea. The incidence of facial flushing is more marked in children than adults. The occurrence of these effects may be reduced by lowering the dose. Side-effects reported less frequently include: cardiac arrhythmias, diarrhoea, dizziness, drowsiness, urinary retention, headache, depression and skin reactions including dry skin, rash, angioderma and photosensitivity. Excitatory CNS symptoms may occur during therapy with oxybutynin including restlessness, confusion, auditory or visual hallucinations, disorientation and convulsions. Children may be more liable to such effects.
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
4.9. Overdose
The symptoms of overdosage with oxybutynin progress from 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.
Measures to be taken: Immediate gastric lavage and physostigmine 1-2mg by slow i. v. injection, repeated as necessary up to a total of 5mg. Fever should be treated symptomatically with tepid sponging or ice packs. In pronounced restlessness or excitation, diazepam 10mg may be given by i. v. injection. Tachycardia may be treated with i. v. propranolol and urinary retention managed by bladder catheterisation. In the event of progression of the curarelike effect to paralysis of the respiratory muscles, mechanical ventilation will be required.
5. PHARMACOLOGICAL PROPERTIES
5.1. Pharmacodynamic Properties
Oxybutynin is an antimuscarinic agent.
Oxybutynin has two main pharmacological effects, an anticholinergic action and a direct antispasmodic activity. Radio ligand binding studies have shown that oxybutynin binds to the M1 subtype of muscarinic receptors. At low doses, it has little or no antagonistic action at the M2-M5 receptor subtypes and less than 10% of the anticholinergic effects of propantheline. It therefore has few common anticholinergic side-effects such as central nervous system or cardiovascular activity. In vitro studies have demonstrated antispasmodic activity probably due to an inhibition of calcium influx into smooth muscle cells. The concentration at which inhibition of calcium influx into smooth muscle cells occurs is approximately 100 times greater than that of selective Ml blockage. The myorelaxant effects may reduce bladder spasm thus decreasing frequency of micturition. Oxybutynin has weak analgesic effects comparable to dextropropoxyphene.
5.2. Pharmacokinetic Properties
Following oral administration oxybutynin, peak plasma concentrations are reached within one hour. A half-life of less than 2 hours has been reported. Oxybutynin has been detected in breast milk.
5.3. Pre-clinical Safety Data
Not applicable.
6. PHARMACEUTICAL PARTICULARS
6.1. List of Excipients
Also contains: cellulose, lactose, talc, magnesium stearate.
6.2. Incompatibilities
None known.
6.3. Shelf Life
24 months.
6.4. Special Precautions for Storage
Do not store above 25°C. Store in the original package.
6.5. Nature and Content of Container
The product is supplied in blister packs in cartons:
a) Carton:
Printed carton manufactured from folding box board.
b) Blister pack:
(i) 250 pm clear and colourless rigid PVC.
(ii) Surface printed 20 pm hard temper aluminium foil.
Pack sizes: 21s, 28s, 30s, 56s, 60s, 84s, 100s, 120s.
6.6. Instructions for Use, Handling and Disposal
Not applicable.
7 MARKETING AUTHORISATION HOLDER
Genus Pharmaceuticals Limited T/A Genus Pharmaceuticals Linthwaite,
Huddersfield,
HD7 5QH, UK
8. MARKETING AUTHORISATION NUMBER(S)
PL 06831/0062
9. DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
30 March 1999
10 DATE OF REVISION OF THE TEXT
04/12/2014