Primary dysmenorrhea refers to a menstrual pain that is not associated with any pelvic disease. It is the commonest cause of menstrual pain and is easily diagnosed from its presentation.
Once the hormone (progesterone), that maintains the endometrial lining of the womb begins to decline, towards the second half of the luteal or premenstrual phase of the menstrual cycle (see: MENSTRUAL CYCLE, OVULATION AND MENSTRUATION: EXPLANATION OF BASIC PHYSIOLOGY for more information), some substances e.g. prostaglandins and leukotrienes are released within the endometrium that actively results in the increased tone and contractions of the uterus (womb) which are then perceived as colicky pains or as menstrual cramps. It is believed that the increased uterine muscle tone and contractions, results in reduced blood flow into the endometrium causing the pain that is characteristic of primary dysmenorrhea.
This presents commonly as cyclical lower abdominal cramps radiating to the back usually felt from or about a day prior to the onset of the menstrual flow. It is worse at the onset, but gradually eases out as the menstruation progresses, often disappearing before the end of the menstrual flow. Often times, it may be associated with gastrointestinal disturbances, such as diarrhoea and vomiting. Characteristically seen only in ovulatory cycles, it is usually cyclical, yet many women with regular ovuation, feel little or no menstrual pain.
It usually appears 6–12 months after menarche, usually when ovulatory cycles have become established in a woman. This is because the earliest menstrual cycles are painless and anovulatory. It has been reported in about 72% of 19-year old women, with 40% requiring regular medications and another 8% missing school at every period, according to a Swedish study. However, its prevalence and severity tend to reduce with age and more significantly after child birth.
This is usually made from the presentation and it hardly requires any investigations. However in cases where doubts exist as to the possibility of a secondary cause i.e. a secondary dysmenorrhea, a thorough physical examination and some investigations may be required to exclude or confirm secondary causes of dysmenorrhea. To learn more about that please read SECONDARY DYSMENORRHEA.
The treatment of primary dysmenorrhea varies based on the severity the symptoms, from mere counseling, to the use of analgesics for symptomatic relief of pain and to the total suppression of ovulation in very severe cases. Below are the various way of treating primary dysmenorrhea:
This involves the use of pain killers for the management of primary dysmenorrhea. In mild cases, paracetamol may suffice but in moderate to severe cases, because prostaglandin analogues are central to the origin of the pain, non steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and mefenamic acid are used to provide excellent pain relief, as they inhibit or prevent the production of these prostaglandin analogues. However, their long term usage, is associated with the occurrence of gastric ulcer and as such, it is advisable to use these drugs with food to reduce this specific risk. Secondly, women hoping to conceive, should only use NSAIDs when they are having the menstrul pain and not close to their ovulation period, as it has been noted that NSAIDs can inhibit or prevent ovulation when used close to the ovulation period, a situation that may be counter-productive in women desirous of pregnancy.
2. SUPPRESSION OF OVULATION
1) Oral contraceptive pills (OCPs): These are contraceptive medications taken daily to prevent ovulation usually in women desirous of contraception. They can be used alone or in combination with analgesics in cases where analgesics alone are not effective in controlling the menstrual pain or in cases in where the adverse effect of NSAIDs prevents their usage. They are desirous for use in women with primary dysmenorrhe, who are desirous of contraception thereby combining the advantage of contraception with prevention or relief of primary dysmenorrhea. Although they are routinely used in single cycles to allow for the monthly flow of menses, in severe dysmenorrhea, “bicycling” and “tricycling” of the OCPs may be done. This refers to cotinuous use of OCPs over two to three months without the usual monthly one week pill free period, which in turn allow the flow of menses only once in two to three months respectively.
2) Depo provera: is a progestogen containing injection taken once in 3 months that acts by preventing ovulation. It offers an excellent contraception at the same time by allow menstruation to occur only once in 3 months, in the process reducing both the frequency and the severity of primary dysmenorrhea. Part of the side effects of this medication however, include irregular vaginal bleeding, weigth gain and mood changes.
3) Mirena: This is an intrauterine device embedded with progestogen that acts locally on the endometrial lining of the uterus (womb) to achieve contraception. Recently, it has along with other progesterone containing intra-uterine devices been approved in many developed countries for the management of severe primary dysmenorrhea. Although primarily meant for contraception, their local effect on the uterus and subsequent absence of menstruation in many of the women using them have made them invaluable for the treatment of dysmenorrhea in women desirous of contraception.
3. OTHER TREATMENT METHODS
1) Lifestyle changes: There is some evidence to suggest that a low fat, vegetarian diet and exercise by improving blood flow to the pelvis may improve the symptoms of dysmenorrhea.
2) Heat: Although a rather old-fashioned method for treating menstrua pain, many people describe considerable relief from the use of hot water bottle on the suprapubic or pelvic area.
3) Finally a few other drugs have been shown to alleviate the symptoms of primary dysmenorrhea despite not being licensed for its management. They include “vasopressin receptor antagonist”, “beta-adrenergic agonists” like salbutamol and “calcium channel blockers” like nifedipine. For more information on this, please CHAT WITH OUR CONSULTANTS for an online consultation.
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3. Marjoribanks J, Proctor ML & Farquhar C. Non-steroidal anti-inﬂammatory drugs for primary dysmenorrhoea. Cochrane Database Syst Rev 2003; 4, CD001751.
4. Brouard R, Bossmar T, Fournie-Lloret D et al. Effect of SR49059, an orally active V1a vasopressin receptor antagonist, in the prevention of dysmenorrhoea. Br J Obstet Gynaecol 2000; 107, 614–9.