Dr. David Kinniburgh on male contraceptive study

(CNN) – On Monday, September 4, the University of Edinburgh's Department of Obstetrics and Gynecology released results of a study on a male contraceptive. Researchers said the contraceptive suppresses daily sperm production and has only minor side effects similar to those with the female pill, such as mood swings, weight gain and increased appetite. The contraceptive, which could come in pill form or as an implant, should be available by 2005.

Dr. David Kinniburgh is a clinical research fellow with the Contraceptive Development Network at the University of Edinburgh.

MESSAGE BOARD Male contraception

Chat Moderator: Thank you for joining our discussion, Dr. David Kinniburgh, and welcome!

David Kinniburgh: Hello to everyone on CNN. Thank you for inviting me to participate.

Chat Moderator: Is the long search for a male contraceptive pill over?

David Kinniburgh: I think this is the beginning of the end of the long wait. And I hope that my research will lead to an available product within the next five to 10 years.

Chat Moderator: What are the side effects of desogestrel?

David Kinniburgh: Desogestrel is an artificial version of the progesterone hormone, which is used in our trial to make the sperm count go down to zero temporarily. It is also used in some female pills and has no serious side effects. But it has a number of minor side effects that many women on the female pill would recognize, such as increased appetite or weight and an alteration in moods.

Question from Haley-CNN: Will the suppressing of daily sperm production be of concern later on when the male decides he would like to have children?

David Kinniburgh: No, this should be of low concern. All the men who took part in the study went back to their original sperm counts. And I know of at least five men in Edinburgh who have had children since finishing the study.

Chat Moderator: How many men were involved in the University of Edinburgh/Shanghai Institute for Family Planning study?

David Kinniburgh: Thirty men took part in Edinburgh and 36 in Shanghai. We are also continuing the study in Capetown, South Africa and Nigeria, where 40 men are taking part.

Question from Fran-CNN: Are there any men who should not use this medication?

David Kinniburgh: All the men who took part in the study were fit and well. They were aged between 18 and 42. Those were restrictions we placed on the study to start. Once we have the pill working, we may be able to widen the types of men who could use it.

Question from Cathy-CNN: How will this change gender dynamics in relationships. Are men expected to take a more active role in birth control?

David Kinniburgh: I think it gives an opportunity for men and women to share the responsibility for contraception. Many women we've asked said this is one of the main advantages in a male contraceptive pill.

Question from Haley-CNN: Is there any concern that by providing men with an oral contraceptive, diseases such as HIV will increase?

David Kinniburgh: Unfortunately, HIV is already increasing and is likely to be one of the major health concerns over the next century. We do not want to detract from the use of condoms for safe sex and would advise all couples to use condoms for HIV prevention.

However, the opportunity to have an effective and reversible contraceptive pill for men will give couples a much wider choice for contraception. Women already have a contraceptive pill, and this should not stop them from using condoms for HIV prevention. And it should be the same for men.

Question from Cathy-CNN: Does the pill work on a cycle like the female counterpart?

David Kinniburgh: The male pill works -- if taken -- and works continuously, because men are continuously producing sperm. A man may produce thousands of sperm per second, whereas a woman produces one egg per month.

Question from Jason: Is it a once-a-day dose as with women contraceptives?

David Kinniburgh: Yes. In the study, the men took one dose per day of the pill desogestrel. They also received testosterone every 12 weeks.

Question from Philo-CNN: How long from when you start taking this pill until it's "effective"?

David Kinniburgh: All the men had a zero sperm count by 16 weeks of treatment. Most men had a very low sperm count within 8 weeks of taking it. It will be somewhere between those two times that we decide it will become effective, and that will need more research.

Question from Jason: What is the mechanism of action for this pill?

David Kinniburgh: Desogestrel inhibits the signal from the pituitary gland that tells the body to make sperm and also to make testosterone. The sperm count drops to zero, while we give back the testosterone, so that the levels of that hormone are normal. When the pill is stopped, everything just goes back to normal, and the sperm count returns.

Question from Fran-CNN: So how did men in the study feel about taking this medication and being responsible for the birth control in the partnership?

David Kinniburgh: All the men were volunteers for this research trial and were very keen to start with. Not only did they have to remember to take the pill, but they also had lots of tests and sperm counts done. Most of them were in long-term relationships where there was already a problem with contraception. So both the man and the woman really appreciated having this extra choice. Eleven of the men were so keen, they continued taking the pill for an extra six months and, even then, were reluctant to stop.

Question from LJNoel-CNN: How much would the pill cost? Cheaper or more than regular birth control pills?

David Kinniburgh: The pill we used was part of a research study and is not available at the moment. And it will not be available for at least five years. The price at that time will depend on the drug company. I would expect it to be comparable to modern female pills, however.

Question from Susie-CNN: Are there dangers from long-term use of this?

David Kinniburgh: We will need much larger and longer studies to have a definite answer about long-term effects. It has taken 40 years of the female pill for us to fully understand how it works. There are no indications in our own study on the male pill that there are any problems as yet, but it is too early to be sure.

Question from Philo-CNN: Why do you figure it's taken longer to make a "pill" for men?

David Kinniburgh: There are two technical reasons why it is more difficult to have a male pill than a female pill. As I have said, men produce thousands of sperm every second, and women produce just one egg each month. So a male pill has a much bigger job to do. The second reason is that you must give men testosterone to keep the hormones balanced.

Unfortunately, testosterone cannot be taken as a pill, as it is destroyed in the liver if you swallow it. You also need to give very large amounts of testosterone, which the man needs every day. That is why we used implants in our study, but we hope to have injections available for the next study.

Question from Susie-CNN: I can't even get my husband to finish a run of antibiotics. What happens if they skip a few days?

David Kinniburgh: We need more information to say for sure. However, it takes 70 days for a man to make a sperm and only seven days for a woman to produce an egg. Hopefully, this means one pill missed will not be vital. However, we hope all the pills will be taken every day. The men in the study managed this very well, as they realized the importance of good pill taking.

Question from Jason: So the testosterone would have to be injected daily?

David Kinniburgh: The testosterone will be injected, at most, every month -- once per month – or, hopefully, once every two or three months.

Question from Rec: Dr Kinniburgh, did you say 70 days to make a sperm, but men create thousands of sperm per minute?

David Kinniburgh: Yes. It takes 70 days to make a sperm from scratch, but this process is going on all the time. So there are always new ones coming off the production line.

Question from QuigonJ: Do you recommend it for teenagers?

David Kinniburgh: Most of the men in the study and most of the men I would expect to use the pill would be in long-term relationships where there is already trust between the man and the woman.

I don't think teenage boys would be motivated to take the pill, and I definitely don't think female teenagers would trust a boy. It is more important for teenagers to be practicing safe sex using condoms -- at that point in life.

Question from Is: How can someone sign up for one of these clinical tests or studies?

David Kinniburgh: Anybody who lives in the Edinburgh area would be eligible. Unfortunately, that's not much use for anyone in the United States or further afield. There are other centers in Europe that are doing the next study, and you should check with your local family-planning doctor or contact the University of Edinburgh.

Chat Moderator: Are there benefits to desogestrel other than suppression of sperm production?

David Kinniburgh: The men in the study all had normal testosterone levels, although these levels were slightly lower than when they weren't taking the pill. This may have long-term benefits of the prostate gland, but it will need much longer studies to show this.

Question from Is: Have you conducted any surveys to determine the percentage of men willing to undergo these implants and taking a pill every day? I mean, it’s fine that many women do it, but love alone won't make most men subject themselves to this.

David Kinniburgh: We asked men if they wanted to take the pill before we did any studies with actual pills. We asked almost 2,000 men in Edinburgh, Shanghai, Hong Kong and Capetown what they thought of a male pill. The majority of men in all four cities liked the idea and would use it. The Caucasian men, in particular, made it their first choice -- if it was available.

We also did a similar questionnaire in the same four cities, asking 2,000 women if they wanted the men to take the pill. Ninety percent of them thought it was a good idea, and only 36 out of 2,000 wouldn't trust their men to take a pill. So both men and women want the choice of a male contraceptive.

Chat Moderator: Do you have any final thoughts for our audience?

David Kinniburgh: Thanks for all the good questions. I hope we will be able to produce a male contraceptive pill for all those interested. If you would like more information, we have a Web page on the University of Edinburgh Web site: www.ed.ac.uk.

Chat Moderator: Thank you for joining our chat, Dr. David Kinniburgh.

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The Obstetrics & Gynaecology Server
University of Edinburgh Department of Obstetrics and Gynecology
Population Council
AVSC International
Planned Parenthood Federation of America
American College of Obstetricians and Gynecologists

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