Medical Treatment If the patient desires treatment of pain symptoms that are suggestive of endometriosis in the absence of a definitive diagnosis, empirical treatment is appropriate and includes counseling, analgesia, nutritional therapy, progestins, or combined oral contraceptives. It is unclear whether oral contraceptives should be taken in a conventional, continuous, or tricycle regimen. A GnRH agonist may be taken, but is not recommended, because this class of drug is more expensive and associated with more side effects and concerns about bone density than oral contraceptives (1).
Women suffering from dysmenorrhea are treated with analgesics; many women treat themselves with over-the-counter oral analgesics. Primary dysmenorrhea is defined as menstrual pain without organic pathology, based on physical examination alone, and it can be argued that some women with so-called primary dysmenorrhea probably have endometriosis (345). In a systematic review it was concluded that nonsteroidal anti-inﬂammatories (NSAIDs), except niﬂumic acid, were more effective than placebo for relief of primary dysmenorrhea, but there was insufficient evidence to suggest whether any individual NSAID was more effective than another (345). In another review, selective cyclo-oxygenase-2 inhibitors rofecoxib and valdecoxib were as effective as naproxen and more effective than placebo for the treatment of primary dysmenorrhea (346). Concerns were raised about the safety of these medications, and its manufacturers withdrew rofecoxib from the market.
According to another systematic review based on two relatively small, randomized controlled trials comparing paracetamol and coproxamol with placebo, coproxamol (paracetamol 650 mg and dextropropoxyphene 65 mg) but not paracetamol (500 mg 4 times daily) was more effective than placebo in reducing primary dysmenorrhea (346). This observation may be explained by the suboptimal dosage of paracetamol used. A small randomized trial demonstrated that paracetamol (acetaminophen) 1,000 mg four times daily was superior to placebo for the treatment of primary dysmenorrhea (347).
There is a paucity of information for the use of modern OCs for primary dysmenorrhea. A Cochrane review suggested that first-and second-generation OCs with 50 μg or more estrogen may be more effective than placebo treatment for dysmenorrhea. It concluded that the studies included for analysis were of poor quality and heterogenous so that no recommendation could be made regarding the efficacy of modern, lower dose OCs (evidence level 1a) (348). A randomized controlled trial comparing a low-dose oral contraceptive containing 20 μg ethinyl estradiol and 100 μg levonorgestrel with placebo showed better pain relief in adolescent girls with dysmenorrhea using the OC than placebo (349).
There is some evidence in general populations that OCs can effectively treat dysmenorrhea (350). OCs have the advantage of long-term safety; hence they can be used indefinitely in low-risk women. In clinical practice, when they are used for menstrual pain, they may be taken tricyclicly or continuously to reduce the number of periods or avoid them altogether (evidence level 4). There is no direct comparison of these options with the conventional approach.
Several Cochrane reviews and one clinical-evidence review suggest that other treatment modalities that might be helpful in primary dysmenorrhea include supplemental thiamine or vitamin E, high frequency transcutaneous nerve stimulation, topical heat and herbal remedy toki-shakuyakusan. They suggest that treatment modalities with unknown benefit are vitamin B12, fish oil, magnesium, acupuncture, other herbal remedies and behavioral interventions, and that spinal manipulation is unlikely to be beneficial (348,350–352).