Clinical Research Directory

Inclusion Criteria: 1. Patients with a uterus. 2. Ages 18 to 55 years. 3. Undergoing any intrauterine device (IUD) insertion. 4. English-speaking participants. 5. Ability to use an inhaler device. 6. Willing to receive a cervical block for their IUD insertion Exclusion Criteria: 1. Inability to provide informed consent. 2. Confirmed pregnancy. 3. Use of pain medication other than NSAIDs or acetaminophen (e.g., opioids, benzodiazepines, muscle relaxants) within 24 hours prior to the intervention. 4. Use of cannabis within 24 hours prior to the intervention. 5. Administration of misoprostol within 24 hours prior to the intervention. 6. Altered level of consciousness due to any cause, including head injury, drugs, or alcohol. 7. History of severe adverse reactions to Penthrox (methoxyflurane) or other halogenated anesthetic agents, or to any ingredient in the formulation (including non-medicinal ingredients or container components). 8. Anatomical variance, such as distorted uterine cavity, bicornuate uterus, uterus didelphys, or cervical stenosis. 9. Clinically significant renal and/or liver impairment. 10. Known or genetic susceptibility to malignant hyperthermia. 11. Clinically evident hemodynamic or cardiovascular instability, or respiratory depression. 12. Not NPO according to hospital guidelines.