Medication management of chronic pelvic pain
Women look to gynaecologists when they have pelvic pain and appreciate a complete care approach. By improving our own skills, the majority of cases can be managed without the need for pain specialist referral.
Chronic pain is pain that has
involvement in activities with ‘high motivational value' for her will
been present on most days for
encourage participation. This might include volunteering at a school
more than three to six months.
if she enjoys being with children, study in an area that interests
This fits easily with our patients
her, or craft activities she has always enjoyed. Both exercise and
who may have started with severe
enjoyable activities help make pain a smaller part of her life.
dysmenorrhoea in their teens, but
who now have pain on most days
Neuropathic medications for chronic pelvic pain
through the month.
Pain pathways involve a wide range of different receptors, so there
Pain Medicine Physician
are many medications with potential benefit. From a pelvic pain
Pelvic Pain SA
Another commonly used definition
perspective, easily prescribed useful options include:
is pain that is still present after
• a tricyclic, preferably amitriptyline, but also nortriptyline;
the time healing should have
• a serotonin-norepinephrine reuptake inhibitor (SNRI)
occurred, following trauma or surgery. This fits well with chronic
medication, such as duloxetine, venlafaxine or desvenlafaxine;
pain post childbirth or post surgical pain.
• an anticonvulsant such as pregabalin or gabapentin.
Both situations represent a physical and chemical change in the way nerve pathways and the central nervous system function. Her pain
Explaining at the beginning that each of these medications suits
is now both a peripheral (pelvic) and central (brain and spinal cord)
around half those who take it, and that we may need to try more
condition. Considering only pelvic conditions is now less likely to
than one before getting the right combination is advisable.
successfully manage all her symptoms.
Improved ways of determining which medication suits which patient are an active area of current worldwide research.
Evidence for the presence of central changes in chronic pelvic pain is summarised in the recent article by Brawn et al.1
Most pain research has been done in either male rodents or male humans and we should not presume that either the pain pathways
Why should gynaecologists manage this condition?
or the doses recommended are applicable to girls and women.3
With so many girls and women affected, managing chronic pelvic
Generally starting with a lower than usual dose and increasing at
pain becomes a workforce planning issue. There are far too many
a slower than usual pace, to a lower than usual peak dose works
girls and women affected for everyone to attend a multidisciplinary
best. A small acceptable dose with moderate benefit is better than a
pain unit and pain clinics rarely include gynaecological expertise.
larger dose that is discontinued owing to side effects.
Where pain remains unmanaged, an increasing number of
In the absence of robust clinical trials of neuropathic pain
our patients will be prescribed regular opioids by their general
medications in a pelvic pain population, the following
practitioner, who may perceive there are no alternative options. With recommendations are those we use for girls and women. opioid overdose deaths (often accidental using prescribed opioids) now outnumbering road deaths in Victoria2, it is imperative that
safer and more effective pain management options be offered.
Amitriptyline is a good choice for an overactive bladder, poor sleep, pelvic muscle pain, headaches, bloated feelings, provoked
vestibulodynia, loose bowels or tender points in muscles. It is
Regular exercise should be considered essential rather than optional inexpensive and easily available.
for any chronic pain patient. Pacing activity and starting with low intensity ‘non-core' exercise is recommended. Where obturator
Starting with 5mg (half blue tablet) early in the evening and
internus spasm (sudden or stabbing pains in the side or back) is
increasing very slowly to between five and 25mg usually avoids
present, core exercises (Pilates, sit ups, planking) aggravate pain
too much morning sedation. Anecdotally, a small dose (10mg)
and should be avoided. Walking is a good choice and, even where
each evening continued long term reduces pain recurrence over
relatively immobile, a ten-minute walk daily is not unreasonable.
the longer term. When discontinued, she may feel well initially
Exercise with a variety of different movements ‘away from the core'
with recurrence of pain weeks or months later. If so, restarting
(dancing, team sports) is usually better tolerated.
amitriptyline is often effective.
Pain psychology has been shown to reduce chronic pain and
Tricyclics should be avoided in women with glaucoma, a short QT
1 O&G Magazine
interval on ECG, urinary retention, severe constipation or epilepsy.
the use of opioids. Improving our skills prescribing neuropathic
If sedation is a concern, then changing to the same dose of
medications may reduce the chance that our patients become
nortriptyline is often acceptable, but may not be as effective.
The majority of anti-anxiety medications have minimal impact on
Serotonin syndrome is an uncommon, but possible, complication
chronic pain. However, those that have both serotonin-specific
when combining certain medications. It is quite uncommon when
reuptake inhibitor and SNRI activity do help pain. SNRI medications
using low dose tricyclics with an SNRI – but possible any time
include duloxetine, venlafaxine and desvenlafaxine. They are a
the dose of either medication is increased. The risk of serotonin
good choice for women with anxiety, pain, fibromyalgia, pelvic
syndrome increases substantially if a third medication affecting
muscle pain, weight concerns or low mood, and may also help an
serotonin is added and this situation should be avoided.
overactive bladder. Side effects include nausea, loss of appetite,
Medications affecting serotonin include tramadol; monoamine
looser bowels, weight loss, feeling more ‘awake' and, in some
oxidase inhibitors; illicit drugs, including amphetamines; St John's
women, difficulty with orgasm.
Wort; dextromethorphan (cough medicines); metoclopramide; and ondansetron.
The normal dose for duloxetine is a 30mg capsule taken in the morning for two weeks then 60mg in the morning. However, it
Symptoms of serotonin syndrome include:
is better tolerated when started at 15mg every morning. This is
• agitation, confusion, headache;
achieved by opening the capsule, removing and discarding half the
• shivering, sweating, diarrhoea, high BP, rapid HR; and
granules, and closing the capsule before taking it.
• muscle rigidity, twitching, dilated pupils.
If sleep is poor on duloxetine, then adding 10mg of amitriptyline
Treatment involves discontinuing medications, managing agitation
in the evening may improve sleep and further enhance pain
with benzodiazepines and if necessary using the serotonin
management. Duloxetine is available as a PBS medication in
antagonist, cyproheptadine (Periacten).
patients with depression.
Pregabalin or gabapentin (alpha-2-delta ligands)
Brawn, J., et al. (2014). Central changes associated with chronic
These medications are useful for pain generally, and have been
pelvic pain and endometriosis. Hum Reprod Update. [Epub ahead of
used particularly for post-herpetic neuralgia, diabetic neuropathy,
print] PMID: 24920437.
Overdose worse than the road toll - fact sheet accessed at: www.
pudendal neuralgia and neuropathic pain. Side effects include
dizziness, drowsiness, confusion and weight gain.
Joel D. Greenspan, Rebecca M. Craft, Linda LeResche, Lars Arendt-Nielsen, Karen J. Berkley, Roger B. Fillingim, et al. Studying sex and
Pregabalin is available in 25 and 75mg capsules. The normal
gender differences in pain and analgesia: A consensus report. Pain.
starting dose recommended for chronic pain is 75mg twice a day.
2001 Jan 89(2-3):127-34.
However, we initiate treatment using 25 or 37.5mg at night and
Darnell BD, Stacey MD, Chou MD. Medical and psychological risks
increase slowly. Pregabalin is 100 per cent soluble in water, so a
and consequences of long-term opioid therapy in women. Pain Med
75mg dose can be reduced by opening the capsule, dissolving
2012 13: 1181–1211.
Dobbin M. Pharmaceutical drug misuse in Australia. Aust Prescr 2014
the contents in water then drinking half (or a third) of the fluid. It is
stable in water for 24 hours. Pregabalin is indicated in Australia
Lee, M., et al. (2011). A comprehensive review of opioid-induced
for neuropathic pain as a streamlined 4172 authority script. These
hyperalgesia. Pain Physician 14(2): 145-161.
medications do not affect serotonin.
Tricyclics, SNRIs and anticonvulsants are all Category C risk in pregnancy.
Regular opioid use became popular with the rise of palliative
care protocols, where the patients' condition was terminal. In our
patients with benign long-term pain their regular use should be
Drug overdose deaths are now more likely to involve prescribed than illicit medications and are frequently accidental. Fentanyl supply increased 46 times between 1997 and 2012 in Australia and oxycodone is now the seventh-most commonly prescribed drug in Australian general practice.5
Of particular importance, there is increasing evidence that narcotics sensitise nerve pathways when used regularly.6 Opioids thus contribute to the pain condition and worsen chronic pain when used regularly, rather than improve it.
In contrast, neuropathic medications are more effective, do not sensitise nerve pathways, can be used long term and may avoid
Vol 16 No 3 Spring 2014 2
Carbamate and Pyrethroid Resistance in the Leafminer J. A. ROSENHEIM,' AND B. E. T ABASHNIK Department of Entomology, University of Hawaii at Manoa, Honolulu, Hawaii 96822 J. Econ.Entomol.83(6): 2153-2158 (1990) ABSTRACT Populations of D1glyphus begini (Ashmead), a parasitoid of Lirlomyza leafminers, showed resistance to oxamyl, methomyl, fenvalerate, and permethrin in labo-ratory bioassays. Relative to a susceptible strain from California, maximum resistance ratiosfor these pesticides were 20, 21, 17, and 13, respectively. Three populations that had beentreated frequently with insecticides were significantly more resistant to all four insecticidescompared with an untreated Hawaii population and a California population with an unknownspray history. Parasitoids from a heavily sprayed tomato greenhouse on the island of Hawaiihad LC",'s for permethrin and fenvalerate that were 10 and 29 times higher than the fieldrate, respectively. Populations resistant to oxamyl and methomyl had LC",'s two- and sixfoldbelow the field rate, respectively. D. begini is one of the few parasitoids resistant to pyre-throids, with LC",'s exceeding field application rates. Resistant D. begini may be useful forcontrolling leafminers in management programs that integrate biological and chemical con-trols.
A Guide to the Diagnosis & Management of Myasthenia GravisJoël Oger, MD, FRCPC, FAA. Dr. John Newsom-Davis 1932-2007 Expert reviews: J. Newsom-Davis CBE, MA, FRCP, FRS, Design & illustration: L.Waters, MFA, MScBMC, Waters Biomedical Acknowledgements:I thank Talecris Biotherapeutics for making this booklet possible through an unrestricted educational grant, and Kim Fisher, PhD, for her support. I would also like to thankLori Waters for the illustration and design.