Lack of tubal occlusion by intrauterine quinacrine and tetracycline in the primate

What happened to quinacrine non-surgical female sterilization?

Quinacrine sterilization (QS) is a nonsurgical female method used by more than 175,000 women in over 50 countries. With FDA approval, QS is expected to be used by hundreds of millions of women. The negative international health consequences of the results of a 2-year rat study in 2010 by Cancel et al. in Regulatory Toxicology and Pharmacology (RTP) (56:156-165) are incalculable. S1C(R2) was ignored in this study, including the fundamental concept of maximum tolerated dose (MTD), which resulted in the use of massive doses (up to 35 times the MTD) which killed many of the rats and destroyed the uterus of survivors. The design of this rat study was built on the false assertion that this study mimics what happens in women. Cancel et al. (2010), concludes it "seems most likely" that genotoxicity was a major factor in the carcinogenicity observed, prompting the FDA to halt further research of QS. In RTP, McConnell et al. (2010), and Haseman et al. (2015), using the authors' data, definitively determined the carcinogenicity to be secondary to necrosis and chronic inflammation. Decisions made in the design, conduct, analysis, interpretation and reporting in this study lack scientific foundation. This paper explores these decisions.

Quinacrine-induced occlusive fibrosis in the human fallopian tube is due to a unique inflammatory response and modification of repair mechanisms

Quinacrine has been widely used in treatment of parasitic diseases such as malaria and giardiasis, and in the treatment of autoimmune diseases. Quinacrine has also been used as an effective substitute for surgical contraception by causing occlusion of the fallopian tube. This minimally invasive treatment protocol involves intrauterine insertion of the drug in the form of pellets and has been studied in humans in a number of countries, including the United States. Despite its development in the 1970s, the cellular and molecular events induced by quinacrine in the human fallopian tube have not been described. Here we describe a plausible mechanism for quinacrine action in the fallopian tube. This is manifested as an acute pro-inflammatory response in the uterus and fallopian tube, characterized by loss of epithelial cell adhesion. This response relies on properties of gated channels found on the surface of epithelial cells in the reproductive tract. While the uterus returns to normal, the inflammatory response affects the uterotubal junction and transmural segment of the human fallopian tube, and initiates formation of mature collagen in the lumen of the fallopian tube, resulting in its permanent occlusion. The response within the fallopian tube appears similar to the protective mechanisms that have evolved in women to minimize the likelihood of systemic infection from Neisseria gonorrhoeae, and to some extent from Chlamydia trachomatis. This review could assist in development of experimental models used in investigating the mechanisms of fibrotic responses in humans as well as development of techniques for permanent non-surgical female contraception.

Transcervical Sterilization: Past, Present, and Future

After multiple attempts at developing transcervical sterilization techniques over the past 150 years, United States women now have the option of a transcervical method, which can be performed without an incision under local anesthesia. It is feasible in most patients and highly effective once occlusion has been confirmed with hysterosalpingogram. Another method is likely to be approved and enter the market in the near future. Expanded choices for sterilization are a positive development for women's health because more options may decrease unintended pregnancy.

Transcervical sterilization

The transcervical approach to permanent female sterilization has been studied for more than 150 years. Methods for accessing the tubes via this approach include blind, radiological and visual (hysteroscopic) techniques. Modalities for occluding the fallopian tubes include thermal, chemical and mechanical means. Some combination of the approach and the occlusive method define all known procedures. Initial attempts at transcervical sterilization were not widely adopted due to an inability to occlude the tube reliably, resulting in pregnancy and/or high morbidity from the procedure. Quinacrine sterilization is a procedure that is widely used in the developing world, but this has not been taken up by the developed world. There are limitations in diagnosing tubal occlusion with this technique. New methods for transcervical sterilization include the Essure and the Adiana procedures. These methods involve hysteroscopic placement of devices that rely on both mechanical occlusion and stimulation of tissue ingrowth to effect tubal occlusion. These new devices can be delivered to more than 90% of tubes, have very high success rates of pregnancy prevention (>99% in studies to date) and are acceptable to patients. Most importantly, they can be fitted under local anaesthesia in an ambulatory setting. The cost advantages of transcervical sterilization have not yet been investigated. It is possible that such a modality for permanent female sterilization may be demonstrated to be highly cost-effective.

Studies of quinacrine and of tetracycline for non-surgical female sterilization

The transcervical quinacrine pellet method developed by Zipper and co-workers is potentially a much needed safe, inexpensive, and effective non-surgical method of female sterilization. This method utilizes an intrauterine device inserter to deposit 250 mg of quinacrine hydrochloride as pellets in the uterine cavity. No complications or side effects, other than temporary pain and oligomenorrhea, have been reported. Tetracycline has an established track record for safety. It also has been reported to have properties similar to quinacrine as a sclerosing agent, with potential as a non-surgical method using the quinacrine insertion technique. To expand the experience with quinacrine and to study tetracycline as an alternative, studies were undertaken under the auspices of the Indian Rural Medical Association in Calcutta, India. During the period 14 August, 1979 to 28 June, 1984, 414 women received three insertions of 200 mg of quinacrine. There were 29 failures and a three-year life table failure rate of 8.5. During the period 25 April, 1984 to 28 December 1984, 55 women received three insertions of 200 mg of tetracycline. By 1 June, 1986 there were 32 failures among the 55 cases for a failure rate of 58%. A more recent study using a single dose of 1000 mg of tetracycline also produced unacceptably high failure rates.