Non-Steroidal Anti-Inflammatory Drug (NSAID) Response and Central Sensitization of Pain in Women With Dysmenorrhea

Non-Steroidal Anti-Inflammatory Drug (NSAID) Response and Central Sensitization of Pain in Women With Dysmenorrhea

Menstrual pain is the most common gynecological complaint and the leading cause of school and work absences in reproductive-age girls and women. One of the primary treatments for menstrual pain is use of nonsteroidal anti-inflammatory drugs (NSAIDs; over-the-counter medications such as naproxen, ibuprofen, or aspirin), although up to 18% of women do not get pain relief from these medications. One reason for this may be due to central sensitization of pain, which is when alterations in the central nervous system change how pain is processed in the brain and experienced. Determining the role of central sensitization in menstrual pain is important because central sensitization is associated with the development of chronic pain. Understanding the relationship between NSAID response and central sensitization is important because it could indicate women who may go on to develop chronic pain later in life. This study would directly address this question. Identifying women at risk for chronic pain would help target new treatments to this vulnerable group to ideally prevent pain from becoming chronic. This is particularly important for women in the military because the severity of menstrual pain is associated with missed work, such that in active-duty military women, less than 4.4% with mild menstrual pain missed work, whereas 20.7% of women with moderate to severe menstrual pain missed work. Addressing the significant impact of menstrual pain for military women will help reducing suffering and potentially decrease the risk of developing future chronic pain problems in this population.

Inclusion Criteria:

1. Female aged 18-50 years
2. Menstrual pain rated at least 6/10 on a 0 (no pain) to 10 (worst pain possible) NRS for all menstrual cycles in the previous 6 months
3. Regular menstrual cycles over the past year (at least 9 in the previous 12 months)
4. Self-reported menstrual cycle averaging 22-35 days
5. Access to a smartphone and email, and willing/able to receive text messages
6. Able to read and understand English
7. Ability and willingness to provide written informed consent.

Exclusion Criteria:

1. Use of oral contraceptives or any exogenous hormones in the previous 3 months prior to participation
2. Variable levels of menstrual pain in the previous 6 months
3. Self-reported symptoms consistent with a chronic pain condition (e.g., pain in any body area lasting longer than 3 months) or previous diagnosis of a chronic pain condition
4. Currently pregnant or breastfeeding
5. History of pelvic inflammatory disease or sexually transmitted disease
6. Acute illness or injury that would potentially impact pain task performance (e.g., fever, flu symptoms) or that affect sensitivity of the extremities (e.g., Reynaud's disease)
7. Allergy to naproxen or having a health condition that contradicts use of naproxen or affects naproxen metabolism (e.g., kidney disease)
8. History of high blood pressure or anemia (due to possible complications from NSAID use).