Vaginal yeast infections affect many women. Most are caused by yeast called Candida albicans and quickly clear with topical antifungal medicine. Boric acid suppositories are used in limited circumstances to treat vaginal yeast infections caused by other species of Candida that have not cleared with other medications. Although the Centers for Disease Control and Prevention notes that boric acid suppositories successfully clear about 70 percent of these unusual infections, they can cause vaginal irritation and are highly toxic if accidentally swallowed.
What to Expect
Most women who use boric acid vaginal suppositories as directed experience few, if any, side effects. Unlike oral medications, the ingredients in these suppositories are not absorbed well into the body. Therefore, common side effects that occur with many oral medications -- such as nausea or headache -- do not occur with this medication. However, vaginal irritation or a little watery discharge may occur. If these symptoms are bothersome, a different treatment may be recommended.
When They Are Recommended
Doctors sometimes recommend boric acid suppositories for persistent or recurring vaginal yeast infections caused by yeast called Candida glabrata or Candida tropicalis. Women with diabetes have an increased risk for vaginal infections with these types of yeast. Unlike Candida albicans, which causes most vaginal yeast infections, Candida glabrata responds only about 50 percent of the time to standard topical treatment with commonly used medications, such as clotrimazole (Femcare, Gyne-Lotrimin), miconazole (Monistat, M-Zole) and tioconazole (Vagistat).
Not First-Choice Treatment
Doctors typically do not recommend boric acid suppositories for a vaginal yeast infection caused by Candida albicans. In fact, the medical reference website UpToDate notes that boric acid has "no role in treatment" of such infections, unless cultures show that the Candida albicans causing the infection is resistant to other treatments. This would be a very rare occurrence.
Boric acid vaginal suppositories are generally safe when used as directed, although there is no information about the safety of long-term use. They are relatively inexpensive though somewhat inconvenient to obtain since they typically need to be compounded by the pharmacist. Pregnant women should not use boric acid suppositories. Swallowing boric acid capsules can be fatal, so it's important to keep this medication out of the reach of children. If boric acid is swallowed, seek emergency medical attention.
- Centers for Disease Control and Prevention: Diseases Characterized by Vaginal Discharge
- UpToDate.com: Candida Vulvovaginitis
- Practical Gynecology: A Guide for the Primary Care Physician: Janice Ryden and Paul D. Blumenthal
- Infectious Diseases of the Female Genital Tract: Richard L. Sweet and Ronald S. Gibbs