Download oxybutynin – safe prescribing – a little bit dry 1

®
Best Care for Everyone
OXYBUTYNIN – SAFE PRESCRIBING – A LITTLE BIT DRY
4ENSURE THE INDICATION IS APPROPRIATE
4CHECK FOR GLAUCOMA BEFORE PRESCRIBING
4START LOW AND GO SLOW – ELDERLY PATIENTS REQUIRE LOWER DOSES
4ASK ABOUT ADVERSE EFFECTS AND ACTIVELY MANAGE THESE
Oxybutynin decreases muscle spasms of the bladder and
increases bladder capacity. It is indicated for symptoms of
urinary frequency and urgency1 that result in incontinence.
Oxybutynin can cause classic anticholinergic adverse
effects such as dry mouth, blurred vision, urinary retention,
constipation and confusion. These adverse effects may limit
titration up to effective doses and adherence to therapy.
Make sure patients are aware of these adverse effects and to
report them so they can be effectively managed.
If the patient is non-responsive to oxybutynin or has a
documented intolerance to it, solifenacin and tolterodine
could be considered as alternative options2 however
patients can still experience anticholinergic side effects with
these. Solifenacin and tolterodine are available on Special
Authority.3,4
ENSURE THE INDICATION IS APPROPRIATE
Before prescribing, investigate the cause of incontinence,
and make sure oxybutynin is appropriate. Take care with
older patients who may be more likely to experience adverse
effects with anticholinergic medicines and have an increased
risk of interactions due to multiple medicines prescribed.6
Oxybutynin increases bladder capacity and delays the
desire to void, so it is useful for urgency and frequency
incontinence.1 Oxybutynin is not indicated for stress or
urge urinary incontinence; initial treatment should include
lifestyle interventions such as weight reduction and dietaryfluid modification. These lifestyle interventions will also be
useful for patients who are prescribed medicines such as
oxybutynin for overactive bladder with urgency and frequency
incontinence.2
CHECK FOR GLAUCOMA BEFORE PRESCRIBING
Anticholinergic medicines can aggravate glaucoma, and for
this reason oxybutynin is contraindicated if the patient has
uncontrolled angle-closure glaucoma.1 Oxybutynin should be
used with caution in patients who are susceptible to angleclosure glaucoma.2
Dry eyes
Anticholinergic medicines frequently cause dry eyes; consult
with an ophthalmologist before prescribing oxybutynin to
patients who already suffer from dry eyes.7 For all patients
prescribed anticholinergic medicines, actively enquire about
dry eyes during treatment; offer lubricating eye drops or
alternative medicines if it is particularly troublesome.
Tolterodine can also cause dry eyes. In a study of 52 patients
randomly assigned to tolterodine or oxybutynin, a burning
sensation in the eyes was observed in 43% of those assigned
tolterodine (2mg twice daily) and 58% of those assigned to
oxybutynin (5 mg three times daily).7
Note: Anticholinergic medicines can also impair distant
vision and dilate the pupils leading to increased light
sensitivity. Driving and potentially dangerous activities that
rely on clear vision should be avoided if affected.
START LOW AND GO SLOW – ELDERLY PATIENTS
REQUIRE LOWER DOSES
Oral oxybutynin undergoes gastrointestinal and hepatic
first-pass metabolism producing high plasma levels of an
active metabolite. This metabolite is associated with dry
mouth, constipation and dizziness, which can be especially
problematic for elderly patients.
Elderly patients may only require half the usual dose
of oxybutynin. Start with oxybutynin, 2.5mg twice daily,
and increase only if necessary. Carefully monitor for and
ask about adverse effects, especially if renal or hepatic
impairment are present.1
All anticholinergic medicines should be used cautiously
if patients are cognitively impaired or have Parkinson’s
disease because they can precipitate acute confusional
states. Oxybutynin can also exacerbate symptoms of
hyperthyroidism, coronary heart disease, congestive heart
failure, arrhythmia, tachycardia, hypertension and prostatic
hypertrophy.8
➥ continued
1
Best Care for Everyone
2
OXYBUTYNIN
The topical patch formulation of oxybutynin may reduce the
occurrence of adverse effects compared to oral oxybutynin
because of reduced first-pass metabolism, and lower
plasma levels of the active metabolite.9 The patch may
increase the tolerability of higher doses and can be a useful
option for patients who are likely to experience troublesome
adverse effects with the oral formulation.9 However,
application site reactions and relative cost10
may limit their use.
ASK ABOUT ADVERSE EFFECTS AND ACTIVELY
MANAGE THESE
Many of the adverse effects of anticholinergic medicines are
dose-related; consider reducing the dose before switching
to an alternative medicine or formulation. Some adverse
effects can be effectively managed; inform patients about
these so they know to ask for advice, if needed.
Dry mouth
Dry mouth is the most common and troublesome adverse
effect of all anticholinergic medicines, affecting one in
three patients,11 and is the main reason for discontinuing
oxybutynin.12 Persistent dry mouth can cause ulceration of
the gums, tooth decay, and lead to fungal infections. Advise
patients to maintain good oral hygiene and to use saliva
substitutes, if necessary.
Note: Solifenacin and tolterodine can also cause dry mouth,
but possibly to a lesser extent than oxybutynin.7,12
Gastrointestinal effects
Oxybutynin, like other anticholinergic medicines can
decrease gastrointestinal motility and is contraindicated
in patients with severe ulcerative colitis. Reduced gastric
motility also causes constipation. Ask about constipation at
each visit and manage proactively with dietary advice and
laxatives, where required.
Note: Diarrhoea may be a symptom of incomplete intestinal
obstruction; if diarrhoea occurs, withdraw oxybutynin.1
Decreased sweating
Anticholinergic medicines decrease sweating and can
increase photosensitivity,13 both of which may be problematic
in hot environments. Patients should be informed about
the risk of overheating during exercise or in hot weather
because these can lead to heatstroke and fever.13 Hot baths
and saunas should also be avoided because dizziness or
fainting may result.
Drowsiness and confusion
Older adults have an increased risk of drowsiness,
confusion and memory loss when using anticholinergic
medicines. This risk is further increased if more than one
anticholinergic medicine is prescribed. These central effects
can lead to an increased risk of falls; make sure patients
and their caregivers are aware of this.1
Note: Alcohol may further increase the sedative effect of
oxybutynin; all patients should be advised to limit their
alcohol intake.
Anticholinergic Side Effects14
Peripheral Effects
Potential Medical
Complications
Decreased salivation
Dental caries, gum
ulceration
Decreased sweating
Hyperthermia
Increased pupil size
Photophobia, precipitation
of acute angle-closure
glaucoma
Inhibition of
accommodation
Blurred vision
Difficulty urinating
Urinary retention
Decreased gastrointestinal
motility
Constipation
Central Effects
Drowsiness and confusion
➥ continued
Falls
Best Care for Everyone
3
OXYBUTYNIN
REFERENCES
ACKNOWLEDGEMENTS
1. Apotex New Zealand Limited. Apo-Oxybutynin chloride 5mg tablets and
5mg/5mL syrup, New Zealand datasheet http://www.medsafe.govt.nz/
profs/datasheet/a/apooxybutynintabsyrup.pdf (Accessed 22-04-13)
We wish to thank John Scott, Geriatrician and Clinical Director of Health of
Older Adults Services, Waitemata DHB, for his valuable contribution to this
bulletin.
2. New Zealand Formulary. Urinary incontinence in women http://www.nzf.
org.nz/nzf_4287.html?searchterm=solifenacin (Accessed 29-04-13)
3. Pharmaceutical Management Agency (PHARMAC). Special authority form
Solifenacin (SA0998) http://www.pharmac.govt.nz/2013/08/01/SA0998.pdf
(Accessed 03-07-13)
4. Pharmaceutical Management Agency (PHARMAC). Special authority form
Tolterodine (SA1272) http://www.pharmac.govt.nz/2013/08/01/SA1272.pdf
(Accessed 03-07-13)
5. Hanger C. Managing medicines in older people. Best Practice Journal
2012;47:6-14 http://www.bpac.org.nz/BPJ/2012/October/elderlyMedicines.
aspx (Accessed 08-05-13)
6. Best Practice Advisory Centre. A practical guide to stopping medicines in
older people. Best Practice Journal 2010;27:10-23 http://www.bpac.org.nz/
magazine/2010/april/stopGuide.asp (Accessed 22-04-13)
7. Altan-Yaycioglu R, Yaycioglu O, Akova A et al. Ocular side-effects of
tolterodine and oxybutynin, a single-blind prospective randomized trial.
British Journal of Clinical Pharmacology 2005;59(5):588–92.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1884849/
(Accessed 01-05-13)
8. Arrow Pharmaceuticals (NZ) Limited. Oxytrol Transdermal Drug Delivery
System. New Zealand datasheet 13-12-12. http://www.medsafe.govt.nz/
profs/datasheet/o/oxytroltransdermal.pdf (Accessed 22-04-13)
9. Saltzstein L. Management of overactive bladder in a difficult-to-treat
patient with a transdermal formulation of oxybutynin. Medscape article
511631. http://www.medscape.com/viewarticle/511631_2
(Accessed 22-04-13)
10.Pharmaceutical Management Agency (PHARMAC). Pharmacology and
Therapeutics and Advisory Committee (PTAC) minutes 2007-2008 http://
www.pharmac.govt.nz/2008/10/08/2008-07%20PTAC%20Minutes.pdf
(Accessed 22-04-13)
11.Nabi G, Cody JD, EllisG, Hay-Smith J, Herbison GP. Anticholinergic drugs
versus placebo for overactive bladder syndrome in adults. Cochrane
Database of Systematic Reviews 2006, Issue 4. Art. No.: CD003781.
DOI: 10.1002/14651858.CD003781.pub2. http://onlinelibrary.wiley.com/
doi/10.1002/14651858.CD003781.pub2/abstract (Accessed 03-05-14)
12.Madhuvrata P, Cody JD, Ellis G et al. Which anticholinergic drug for
overactive bladder symptoms in adults. Cochrane Database of Systematic
Reviews 2012, Issue 1. Art. No:CD005429. DOUI:10.1002/14651858.
CD005429.pub2 http://onlinelibrary.wiley.com/doi/10.1002/14651858.
CD005429.pub2/pdf/abstract (Accessed 3-05-13)
13.New Zealand Formulary. Oxybutynin http://www.nzf.org.nz/nzf_4303.
html?searchterm=oxybutynin (Accessed 22-04-13)
14.Lieberman JA. Managing anticholinergic side effects. Primary Care
Companion Journal of Clinical Psychiatry 2004;6(2):20-3 http://www.
ncbi.nlm.nih.gov/pmc/articles/PMC487008/pdf/i1523-5998-6-s2-20.pdf
(Accessed 11-05-13)
For further information on other high-risk medicines visit our website at: www.saferx.co.nz
No: 0182-01-112, Issued: July 2013, Review: July 2015
DISCLAIMER: This information is provided to assist primary care health professionals with the use of prescribed medicines. Users of this information must always consider current
best practice and use their clinical judgement with each patient. This information is not a substitute for individual clinical decision making. Issued by the Quality Use of Medicines Team
at Waitemata District Health Board, email: [email protected]