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Pelvicpain.org.au

Office gynaecology 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 FRANZCOG, FFPMANZCA Neuropathic medications for chronic pelvic pain
through the month.
Gynaecologist, Specialist 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
Office gynaecology 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. opioid dependent.
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 opioids
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
discouraged.4
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

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