The Effect of Nitroglycerin on the Intrauterine Device (IUD) Insertion Experience in Nulliparous Women

The Effect of Nitroglycerin on the IUD Insertion Experience in Nulliparous Women: a Pilot Study

Increasing ease of access of long-acting birth control methods, like intrauterine devices (IUDs), is an important way to reduce the risk of unintended pregnancy. Unfortunately, fear of IUD insertion in women who have not had children is common among health care providers and women alike, and this limits IUD use. To increase acceptance of this highly effective birth control method, there is a need to explore new, low cost, and easily applied methods to improve the insertion experience. This is a pilot study to evaluate the effectiveness and acceptability of nitroglycerin ointment applied vaginally to improve the IUD insertion experience for both patient and provider. The investigators hypothesis is that nitroglycerin ointment will decrease the pain associated with IUD insertion.

Study Overview

• Status: Completed
• Conditions: Pain; Contraception
• Intervention / Treatment: Drug: Insertion of nitroglycerin ointment; Drug: Insertion of placebo ointment

Detailed Description

Increasing acceptability and use of long acting reversible contraceptive methods like the intrauterine device (IUD) is an important strategy to reduce the risk of unintended pregnancy. Unfortunately, fear of IUD insertion in nulliparous women is common among health care providers and women alike, and this limits IUD use. While many health care providers assume that placement is more difficult in nulliparous women, there is no evidence that the risk of unsuccessful insertion is higher. Women worry about pain with insertion, and their fear is not unfounded as U.S. and international data have shown that nulliparous women report approximately twice as much pain with IUD insertion compared to parous women.

A key difference between nulliparous and multiparous women is the resistance of the cervix. While cervical dilation is uncommonly needed during IUD placement, force is often required to pass the insertion device through the internal os. Although misoprostol and ibuprofen have been studied as ways to improve the IUD insertion experience, neither has proved effective, and misoprostol actually has been shown to increase pain. Therefore, to increase acceptance of this highly effective contraceptive, there is a need to investigate novel, low cost, easily applied and accessible techniques to improve the insertion experience.

Nitric oxide (NO) donors, including nitroglycerin, nitroprusside, isosorbide mononitrate and isosorbide dinitrate, have effects on the animal and human cervix. Both nitroglycerin and isosorbide mononitrate tablets administered vaginally have been shown in RCTs to induce effective cervical ripening with minimal side effects for first trimester abortion compared to placebo. Nitroprusside and isosorbide dinitrate gel given intracervically prior to first trimester abortion also have showed minimal side effects in several RCTs, but with mixed results regarding effectiveness. Additional safety data about NO donors applied topically to skin and mucosal surfaces is well established through the routine use of topical nitroglycerin for treatment of anal fissures.

Although a recent randomized controlled trial (RCT) comparing nitroprusside gel to misoprostol for cervical ripening prior to first trimester surgical abortion found superior cervical dilation in the misoprostol group, there was no significant difference in cervical dilation up to 5 mm. While most studies of abortion are concerned with providing adequate dilation beyond 8 mm, the cervical remodeling that is necessary to help with IUD insertion is much less, as the levonorgestrel intrauterine system (LNG-IUS) inserter is only 4.75 mm in diameter. Since NO donors are smooth muscle relaxants, they are expected to induce cervical ripening without causing uterine cramping, which is the most significant side effect of misoprostol.

Nitroglycerin is inexpensive, stable at room temperature, and readily available in tablet and ointment form, as well as in a dextrose solution for intravenous administration. The ointment form is commonly applied topically for the treatment of anal fissures. We propose the following aims:

1. To determine if nitroglycerin ointment applied vaginally 30-45 minutes prior to IUD insertion improves pain among nulliparous women compared to a placebo ointment. Self-reported pain scores on a 100 mm VAS will be assessed at multiple time points during and after the IUD insertion procedure. In addition, overall satisfaction and adverse effects will be evaluated.
2. To determine if nitroglycerin ointment applied vaginally 30-45 minutes prior to IUD insertion improves ease of IUD insertion for the provider compared to a placebo ointment. In addition, need for additional dilation, additional pain medicine such as paracervical block, inability to place the IUD, and complications will be tracked.
3. To determine if nitroglycerin ointment applied vaginally 30-45 minutes prior to IUD insertion is safe and well tolerated. Side effects related to treatment with nitroglycerin ointment or placebo will be compared. Blood pressure will be measured at multiple time points.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Oregon
    • Portland, Oregon, United States, 97239
      • Oregon Health & Science University
    • Portland, Oregon, United States, 97212
      • Planned Parenthood Columbia Willamette

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

1. age 18-45 years,
2. generally healthy,
3. requesting a LNG-IUS for contraception as the primary indication

Exclusion Criteria:

1. Previous pregnancy beyond 20 weeks;
2. previous IUD placement or attempted IUD placement;
3. previous cervical cold knife cone (CKC) or loop electrosurgical excision procedure (LEEP);
4. contraindication to LNG-IUS (including pregnancy, fibroids that distort the uterine cavity, exam consistent with PID, allergy to any component of the LNG-IUS, etc);
5. concurrent use of any form of nitrate therapy or medications that interact with nitroglycerin (such as phosphodiesterase V inhibitors);
6. known allergy to nitroglycerine or common topical ointment ingredients;
7. known renal or hepatic impairment;
8. history of hypertensive or hypotensive disorder;
9. history of migraine, cluster headaches, or vascular headaches;
10. history of myocardial infarction;
11. uncontrolled congestive heart failure;
12. unstable angina;
13. tobacco or alcohol amblyopia;
14. congenital optic atrophy;
15. blood pressure less than 90/55 or greater than 150/100 in office prior to speculum exam

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo ointment	Drug: Insertion of placebo ointment; Placebo ointment inserted into the vagina 30-45 minutes prior to IUD insertion
Active Comparator: Active nitroglycerin ointment	Drug: Insertion of nitroglycerin ointment; Nitroglycerin ointment inserted into the vagina 30-45 minutes prior to IUD insertion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient-reported Pain at Passage of Insertion Device Through Cervix, as Measured on a 100 mm VAS	Patient-reported pain at passage of insertion device through cervix, as measured on a 100 mm VAS. VAS anchors: 0 indicates no pain, and 100 indicates worst pain imaginable.	30-45 minutes after insertion of nitroglycerin ointment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Provider Ease With Intrauterine Device Insertion Measured on a 100 mm VAS	Provider ease with intrauterine device insertion measured on a 100 mm VAS. VAS (visual analog scale) anchors: 0 indicates easiest insertion imaginable, 100 indicates most difficult insertion imaginable	30-45 minutes after insertion of nitroglycerin ointment

Collaborators and Investigators

• Sponsor: Oregon Health and Science University
• Collaborators: Bayer; American College of Obstetricians and Gynecologists

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2012
• Primary Completion (Actual): November 1, 2012
• Study Completion (Actual): November 1, 2012

Study Registration Dates

• First Submitted: December 8, 2011
• First Submitted That Met QC Criteria: December 9, 2011
• First Posted (Estimate): December 12, 2011

Study Record Updates

• Last Update Posted (Actual): April 26, 2019
• Last Update Submitted That Met QC Criteria: April 3, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Keywords: Pain; Contraception; Nitroglycerin; Intrauterine device; Nitric oxide donor; Intrauterine device insertion
• Additional Relevant MeSH Terms: Vasodilator Agents; Nitroglycerin
• Other Study ID Numbers: 7928