Medications can soothe menstrual cramps

Originally published in The Ottawa Citizen September 24 , 2003

Original Title: Cramping my style

It is the most common gynecologic problem women face in their lives. Every month it can wreak havoc in a woman’s ability to function at work, interfere with social interactions and family life. Even after it passes it looms over her shoulder ready to inflict pain and suffering in a seemingly unending cycle.

Painful menstrual cramps (dysmenorrhea) affects up to 90 per cent of women. Although varying in degree, many can attest to the absolute misery they experience each month.

Two types of dysmenorrhea exist: primary and secondary. The former occurs in the absence of any demonstrable pelvic disease. Secondary dysmenorrhea can be caused by tumours, fibroids, sexually transmitted disease, intrauterine devices (IUDs) and endometriosis among other factors.

Primary dysmenorrhea usually begins within three years of the onset of the menstrual cycle (menarche). About 60 to 90 per cent of adolescent females report symptoms of dysmenorrhea. Why does this occur?

The body of evidence suggests a sequence of events that cause pain. During a normal menstrual cycle, estrogen and progesterone will stimulate the cells lining the inner uterine wall (endometrium) to buildup of a substance called arachidonic acid.

When bleeding begins, biochemical reactions within the disintegrating endometrium change arachidonic acid into prostaglandin F2alpha (PGF2alpha) and other substances. PGF2alpha levels are greatest in the first two days of the menstrual cycle.

This prostaglandin produces intense prolonged contractions of the uterus that will restrict blood flow into the uterine muscle (myometrium). The result is similar to an attack of angina; reduced blood flow starves the muscle tissue of oxygen. The muscle responds by using other energy sources that do not require oxygen in order to survive. The net result of this process is a buildup of metabolic byproducts that sensitize the nerve endings that cause uterine pain.

The pain usually coincides with bleeding and ends 12 to 72 hours thereafter. The pain can remain confined to the lower abdomen but for some women it will radiate to the back and legs. Nausea, vomiting, diarrhea, fatigue, headache and malaise can accompany the pain.

The diagnosis of dysmenorrhea requires a thorough medical history and physical examination. The physician needs to know whether the cause is due to gynecologic disease as mentioned earlier or is indeed primary dysmenorrhea.

The medical history should include the age of the woman when she first started her period, the number of days between the first day of each period, the dates of her last two periods, the amount of blood flow, the total number of bleeding days and whether she has any spotting between her periods.

Are there other symptoms with the pain? How severe is it and does it radiate to other regions? Does she experience painful intercourse? Are bowel movements painful? Is the pain unrelated to her period and does it prevent participation in normal daily activities and responsibilities?

What medications have been used to relive the symptoms? Did it work? Did the use of nonsteroidal anti-inflammatory medication (NSAIDs) like ibuprofen (Advil, Motrin) help relieve some or all of her pain? If it did provide pain relief, the diagnosis is more likely to be primary dysmenorrhea.

The pelvic exam is usually normal in women with primary dysmenorrhea. Women with gynecologic disease usually have some physical findings but some may also have a normal examination.

The mainstay of treatment is NSAIDs. This class of medications will block the synthesis of prostaglandins. Between 70 to 85 per cent of women will respond favourably to this treatment. A trial of naproxen (Naprosyn), mefenamic acid (Ponstan) or other NSAID follows if ibuprofen (800 milligrams every four hours) fails to work (NSAIDs can cause stomach upset and bleeding in some individuals. Please discuss dosing with your physician or pharmacist).

The birth control pill is an option for women if NSAIDs are ineffective. It will block the production of arachidonic acid thereby reducing uterine contractions and pain during her period.

Women who do not respond to NSAIDs and oral contraceptives may have a gynecologic disease such as endometriosis causing their pain.

There are some small clinical trials that show other methods relieved symptoms. One trial demonstrated that after a two-month low fat-vegetarian diet women reported a significant decrease in pain intensity.

Another study reported pain reduction using a fish oil supplement (1080 mg eicosapentanoic acid, 720 mg docosahexanoic acid).

The use of a TENS (transcutaneous electrical nerve stimulation) machine seemed to provide pain relief. Physiotherapists often use this device to treat muscle injuries.

These preliminary studies suggest that other modalities may be effective in treating primary dysmenorrhea. Evidence remains scant regarding the effectiveness of acupuncture, herbs and other treatments.

Women should not have to suffer with this condition. Consult your doctor about treatment options.

© Dr. Barry Dworkin 2003

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