Dysmenorrhea in Emergency Medicine Medication

Treatment of dysmenorrhea is aimed at providing symptomatic relief as well as inhibiting the underlying processes that cause symptoms.

NSAIDs reduce prostaglandin production via cyclooxygenase inhibition and are used as first-line therapy for both primary and secondary dysmenorrhea. If taken early enough and in sufficient quantity, they are extremely successful in alleviating menstrual pain. In the ED setting, patients who do not respond to NSAIDs may require treatment with narcotics for pain control. Patients whose symptoms are not relieved by NSAIDs are very likely to have underlying pelvic pathology such as endometriosis.

In a study comparing montelukast, a leukotriene-receptor antagonist, to placebo in patients with dysmenorrhea, montelukast was effective in reducing pain.^[12] Clinicians may consider this as an alternative to hormonal therapy or in lieu of NSAIDs.

COX-2 specific inhibitors have also proven effective in relieving menstrual pain. Their selectivity reduces the GI symptoms caused by inhibition of the COX-1 receptor. However, recent clinical trials have raised their cardiovascular safety profiles into question. As a result, some of these agents are no longer available.

Simple analgesics, such as aspirin and acetaminophen, may also be useful, especially when NSAIDs are contraindicated.

Oral contraceptives, which block monthly ovulation and may decrease menstrual flow, may also relieve symptoms. One recent update of a CochraneDatabase of Systematic Reviews article showed some evidence of symptomatic benefit in patients with primary dysmenorrhea, though no specific preparation showed superiority over another.^[13]

Certain dietary supplements may be effective, though their effectiveness has only been demonstrated in small clinical trials. Thiamine, fish oil, pyridoxine, magnesium, and vitamin E are examples.^{[3, 14]}

Class Summary

These drugs are highly effective in treating dysmenorrhea, especially when they are started before the onset of menses and continued through day 2. They are readily available, relatively inexpensive, and have a low side effect profile when used cautiously and in those who have no contraindications.

Ibuprofen (Ibuprin, Advil, Motrin)

DOC for treatment of mild to moderate pain, if not contraindicated. Inhibits inflammatory reactions and pain, probably by decreasing activity of the enzyme cyclooxygenase, which results in inhibition of prostaglandin synthesis.

Naproxen (Anaprox, Naprelan, Naprosyn, Aleve)

For relief of mild to moderate pain; inhibits inflammatory reactions and pain by decreasing activity of cyclooxygenase, which results in decrease of prostaglandin synthesis. Cost is approximately $3.00/d compared with $0.14/d for generic ibuprofen.

Diclofenac (Cataflam, Voltaren)

Designated chemically as 2-[(2,6-dichlorophenyl) amino] benzene acetic acid, monosodium salt, with an empirical formula of C14 H10 Cl2 NO2 NA. One of a series of phenylacetic acids that has demonstrated anti-inflammatory and analgesic properties in pharmacologic studies. Believed to inhibit the enzyme cyclooxygenase, which is essential in prostaglandin biosynthesis. Can cause hepatotoxicity; hence, liver enzymes should be monitored in first 8 weeks of treatment. Rapidly absorbed; metabolism occurs in liver by demethylation, deacetylation, and glucuronide conjugation. Delayed-release, enteric-coated form is diclofenac sodium, and immediate-release form is diclofenac potassium. Has relatively low risk for bleeding GI ulcers.

Hydrocodone and acetaminophen (Vicodin, Lorcet-HD, Lortab)

Drug combination indicated for moderate to severe pain.