Case-based learning: dysmenorrhoea management

Dysmenorrhoea, commonly referred to as ‘period pain’​, is pain usually felt in the lower abdomen, which occurs shortly before and/or during menstruation​[1,2]​. Prevalence of dysmenorrhoea is difficult to determine owing to the differences in definitions used, criteria for diagnosis, diverse study cohorts and methods for data collection​[2]​. Prevalence rates vary widely in literature, from 15–93% in women of reproductive age, with 2–29% of women with dysmenorrhoea experiencing severe pain​[2–5]​. Although the condition is often underestimated and undertreated, it is a substantial public health burden that can decrease quality of life, restrict daily activities and cause absence from school or work​[2,3]​.

Approximately 30–50% of women affected by primary dysmenorrhoea are reported to miss work or school at least once per menstrual cycle, with 5–14% of women missing work or school more frequently than this​[2]​. Women with dysmenorrhoea also have poorer mood and sleep quality during menstruation than during their pain-free phase, and greater pain sensitivity throughout their menstrual cycle that can subsequently increase susceptibility to other chronic pain conditions (e.g. fibromyalgia)​[2]​​. Despite the impact on quality of life and general wellbeing, few women seek medical treatment and accept the condition as part of their normal menstrual cycle​[2]​.

This article outlines the causes, pathophysiology, diagnosis and management of primary and secondary dysmenorrhoea.

Causes and pathophysiology

Dysmenorrhoea is classified as either primary or secondary; it is not always easy to distinguish between the two based on history and examination alone​​[3]​.

Primary dysmenorrhoea

This type of dysmenorrhoea is not associated with any identifiable underlying pelvic pathology and usually occurs in young females 6–12 months after menarche (i.e. first menstruation), once cycles become regular​​[2]​. It is thought to be caused by the release of uterine prostaglandins during menstruation​​[2]​. Progesterone levels decrease before menstruation, causing endometrial cells to release prostaglandins that then stimulate uterine myometrial contractions​[3]​. This results in decreased blood flow, uterine hypoxia and subsequent pain​​[3]​​. Vomiting, nausea and diarrhoea can also result from the effects of prostaglandins on smooth muscles and are frequently experienced with primary dysmenorrhoea​[2,6]​. Leukotrienes and vasopressin may also play a role in the aetiology of primary dysmenorrhoea​[2,6]​.

Secondary dysmenorrhoea

This type of dysmenorrhoea is caused by an underlying pelvic pathology, such as endometriosis, pelvic inflammatory disease, adenomyosis, uterine leiomyoma (fibroids), ovarian cyst with haemorrhage, obstructive Müllerian duct anomalies, and cervical stenosis​[3]​. It often occurs as a new symptom several years after menarche​[2,3]​​.

Risk factors

Risk factors for primary dysmenorrhoea include:

• Early age at menarche;
• Heavy menstrual flow;
• Nulliparity (i.e. never given birth);
• Family history of dysmenorrhoea;
• Emotional stress​[2,5,7]​.

There is conflicting evidence on the association between primary dysmenorrhoea and modifiable risk factors — such as cigarette smoking, diet, obesity, depression and a history of sexual abuse — and insufficient data to support an association with nutritional deficiency​[7]​. However, in women with iron deficiency, iron supplements can cure or improve dysmenorrhoea​[2,5,8]​​.

Risk factors for secondary dysmenorrhoea are dependent on the underlying cause​​[2]​.

Symptoms

Primary dysmenorrhoea

Pain associated with primary dysmenorrhoea is usually cramping in nature and felt in the lower abdomen, but can radiate to the inner thigh and back​[2,9]​. The pain can be sporadic and intense or constant and dull and may vary with each period​[3]​​. Other features and symptoms of primary dysmenorrhoea include:

• Onset of pain at 6–12 months after menarche (i.e. once cycles are regular);
• Pain commences shortly prior to menstruation and continues for up to 72 hours, improving as menses progresses;
• Non-gynaecological symptoms, such as nausea, vomiting, diarrhoea, fatigue, irritability, dizziness, bloating, headache, lower back pain and emotional symptoms;
• No other gynaecological symptoms;
• Normal pelvic examination​;
• More common in adolescents and women aged under 30 years​[3]​.

Secondary dysmenorrhoea

The onset of pain in secondary dysmenorrhoea often occurs after several years of menstruation (i.e. when a woman is in her 30s or 40s) and is not consistently related to menstruation; however, it may be exacerbated by and persist after menstruation, or be present throughout the menstrual cycle​[2,3]​. Other gynaecological symptoms include dyspareunia (i.e. painful sexual intercourse), intermenstrual bleeding, vaginal discharge, menorrhagia (i.e. heavy or prolonged bleeding) and postcoital bleeding, which may be a result of underlying pelvic pathology​[2,3]​​​. Non-gynaecological symptoms, such as rectal pain and bleeding, may also be present. 

Diagnosis

Secondary dysmenorrhea must be excluded prior to a primary dysmenorrhoea diagnosis​[3]. To exclude secondary dysmenorrhoea, a thorough history should be taken by the pharmacist, including:

• When symptoms started in relation to menarche;
• A description of the pain, including timing and duration, type and severity, and any factors that alleviate or exacerbate the pain;
• Associated gynaecological and non-gynaecological symptoms;
• Length, regularity and duration of menstrual cycle;
• Volume of menstrual flow;
• Presence of risk factors for primary dysmenorrhoea;
• Medical history to identify possible conditions with similar symptoms to dysmenorrhoea (e.g. irritable bowel syndrome and lactose intolerance);
• Sexual history (to exclude, for example, pelvic inflammatory disease);
• Family history (to exclude, for example, endometriosis);
• Obstetric history, including plans for pregnancy;
• Medication history, including effectiveness of previous treatments​[3]​.

If the pharmacist suspects secondary dysmenorrhoea, the patient should be referred to their GP, where a physical examination and other investigations may be required. These examinations and investigations could include:

• A pregnancy test to exclude ectopic pregnancy;
• White blood count, erythrocyte sedimentation rate, C-reactive protein, full blood count and CA-125 test to help exclude, for example, acute or chronic inflammatory disease, anaemia, endometriosis, and ovarian cancer;
• A physical abdominal examination to assess for large fibroids and other masses;
• An ultrasound scan to assess whether there are fibroids and for adnexal pathology;
• A laparoscopy to exclude endometriosis, adnexal pathology, intra-abdominal adhesions and pelvic inflammatory disease;
• A pelvic examination (including a speculum examination of the cervix), except in young women who are not sexually active, to check for or exclude sexually transmitted diseases;
• High vaginal and endocervical swabs to check for or exclude sexually transmitted diseases​[2,3,9]​.

Conditions that are likely to cause secondary dysmenorrhoea and their symptoms are listed in Table 1​​[2,3,7]​​.

Treatment and management

Before advising on the management of primary dysmenorrhoea, secondary dysmenorrhoea must be excluded (see Table 1)​[2,3,7]​. Pharmacists should take a thorough history, including the onset and nature of symptoms, as outlined under ‘Diagnosis’.

Once primary dysmenorrhoea has been confirmed, pharmacists can offer advice on self-management, including the supply of over-the-counter (OTC) medicines for pain. When supplying OTC medicines, pharmacists should consider patient preference and ask about allergies, current medications and medical history to ensure that there are no contraindications, and drug–disease and drug–drug interactions. Advice should be offered on how and when to take the medicine, as well as common side effects to be aware of (see Table 2).

Primary dysmenorrhoea can be treated with simple OTC analgesics. A non-steroidal anti-inflammatory drug (NSAID) — either ibuprofen or naproxen — can be offered over the counter unless contraindicated (see Table 2)​[10]​. Other NSAIDs, including mefenamic acid, flurbiprofen and tiaprofenic acid, can be offered on prescription​​[11–14]​. There is little evidence to suggest variation in efficacy between NSAIDs​ but there are concerns that mefenamic acid is more likely to cause seizures in overdose than other NSAIDs​[15]​​​.

NSAIDS are more effective at treating pain from dysmenorrhoea than paracetamol​[16]​​. Paracetamol should be offered if NSAIDs are contraindicated or not tolerated, and can be taken in addition to an NSAID if the pain is not sufficiently treated with an NSAID alone​​[2]​.

If the patient does not wish to conceive, referral to her GP for a three to six month trial of a hormonal contraceptive could be considered as an alternative treatment​[2]​.

In addition to pharmacological measures, use of a hot water bottle, heat patch or transcutaneous electrical nerve stimulation set at a high frequency can be suggested for further pain relief​[2]​​.

Although the evidence for an association between modifiable risk factors and primary dysmenorrhoea is inconsistent, encouraging smoking cessation, general fitness, a healthy diet and good mental health practices may be beneficial for women experiencing primary dysmenorrhoea​[17,18]​.

Referral

Women should be referred to their GP if symptoms of secondary dysmenorrhoea are reported; their signs and symptoms do not suggest primary dysmenorrhoea​; or non-pharmacological management and pharmacist recommended OTC medicines do not sufficiently address symptoms​[2]​​.

Three cases are presented to illustrate the diagnostic and management advice in this article.

Case 1

A woman presents at her local pharmacy and asks to speak to the pharmacist. She is concerned about her daughter, aged 13 years, who has recently started complaining of period pain and not wanting to eat during her periods.

Assessment

It is important to assess if the patient could have an underlying pathology indicative of secondary dysmenorrhoea or a non-gynaecological condition before making a diagnosis of primary dysmenorrheoa​​[3]​. The discussion should include the following questions:

• How long ago did menstruation begin and is the cycle regular?
• When did menstruation become painful?
• Where is the pain, how severe is the pain and has anything been effective in relieving the pain?
• Does the patient or her family have any other medical conditions?
• Are there any other symptoms?
• Do the symptoms occur only during menstruation or also at other times of the cycle?

After the consultation, the pharmacist learns that the woman’s daughter started menstruating nine months ago and her cycle is now regular. In addition to the dull muscle cramps in her lower abdomen, she also feels nauseous during menstruation, and this is the cause of her loss of appetite. The symptoms usually begin just before menstruation and subside a couple of days later. She does not have any other symptoms, has not had any previous treatment and has no significant medical history or family history of medical conditions.

As there are no signs of underlying disease or secondary dysmenorrhea, the pharmacist is reassured the patient is experiencing pain and nausea as common symptoms of primary dysmenorrhea.

Management and advice

After checking for allergies, and other medicines and medical conditions, the pharmacist advises using a hot water bottle applied to the lower abdomen and ibuprofen 300–400mg up to three times per day, at least four hours apart​[19]​. The pharmacist advises that ibuprofen is usually well tolerated but should be taken with or just after food.

When to refer

If the patient experiences any side effects or if the ibuprofen is ineffective, the patient should be advised to come back to the pharmacy to be reassessed and possibly referred to her GP.

Case 2

A woman, aged 30 years, comes into the pharmacy to purchase naproxen for her period pain. She tells the pharmacist that the pain is quite low down in her abdomen, just above her legs and below her belly button. The duration of pain is not restricted to her periods and she has noticed some vaginal discharge that is often tainted with blood. As she has no other symptoms, she is confident it is period pain.

Assessment

The pharmacist asks the patient about the onset and nature of her symptoms, including any non-gynaecological symptoms, comorbidities and allergies. It is important to determine whether there is something more serious, as the patient’s symptoms and their onset are consistent with secondary dysmenorrhoea​​[3]​. The pharmacist explains the concern and advises the patient to see her GP. The patient would still like to purchase naproxen to help control the pain in the meantime. The patient explains that she had a stomach bleed about three months ago and had to take some tablets for a week. She is not currently taking any other medication, has no allergies and no other significant past medical history.

Management and advice

The pharmacist advises the patient that naproxen is not appropriate because of her recent stomach bleed​ and recommends 500mg paracetamol and some heat patches to apply to her pelvic area​[20]​. She is advised to take two tablets every four to six hours, as required, ensuring that she does not take more than eight tablets per day, including any other preparations that contain paracetamol​​[21]​. The pharmacist explains that paracetamol is usually well tolerated and recommends that she see her GP as soon as possible.

Case 3

A woman, aged 40 years, presents to the pharmacy and explains that she has previously been diagnosed with endometriosis and has been taking a combined oral contraceptive (COC)​. Her symptoms have recently gotten worse and she would like advice on what she can take or do to help relieve the symptoms.

Assessment

It is important to establish whether referral is required. The pharmacist asks the patient about the onset and nature of her symptoms and whether improvement was achieved by the COC; as well as enquiring about any concurrent symptoms, comorbidities and allergies.

The patient explains that her symptoms (cyclical pelvic pain with associated rectal pain and heavy menstrual flow) improved when she started the COC. Apart from the worsening of symptoms, the patient does not have any other symptoms, comorbidities or allergies.

Management and advice

The pharmacist suggests that the patient tries heat packs and warm baths, offers her 300–400mg ibuprofen up to three times per day, at least four hours apart, and reassures her that side effects are uncommon​[19]​. The patient should be reminded to see her GP if symptoms are not relieved and/or persist and informed that her endometriosis may require further investigation and medical intervention, including referral to a medical specialist.

* All cases are fictional