Introduction

Frequent or severe outbreaks of genital herpes can interfere with your work, social activities and disrupt your sex life. Some people with genital herpes have identified factors that may influence frequency or severity of recurrences. Factors such as stress diet and lifestyle may be worth considering when looking at ways of managing herpes in your life. Each case is individual and what works for one may not work for another. The following information is about the use of oral antiviral medicines in controlling recurrent genital herpes.

Three antiviral medicines are available on prescription from your doctor that can treat or even prevent genital herpes outbreaks. They can be taken each time you have symptoms - this is known as episodic therapy - or every day for a prolonged period of time to suppress or prevent symptoms - this is known as suppressive therapy. This leaflet provides information about the medicines used to treat herpes, and how they work.

Why does my genital herpes keep coming back?

Herpes is a common infection caused by herpes simplex virus (HSV) - type 1 or type 2. Genital herpes can affect any part of the genitals, as well as the surrounding areas, including the anus, buttocks and the top of the thighs

Once you have been infected with HSV, it remains permanently in your body, in nerve tissue near the base of the spine, the dorsal root ganglion. Most of the time, the virus is inactive but every so often something happens to reactivate it. Herpes outbreaks (or recurrences) occur when the virus multiplies (replicates) generating new virus particles that travel along the nerve to the original site of infection. This causes the symptoms you recognise. Sometimes, the virus can replicate and be shed from the site of infection without recognisable symptoms - this is referred to as asymptomatic shedding.

We don't know why HSV reactivates at particular times. You may recognise trigger factors that contribute to an outbreak. These may include friction due to sexual intercourse, ill health, stress, fatigue, depression, lack of sleep, direct sunlight and menstruation. Trigger factors differ from person to person. If you are unclear about whether particular triggers cause your outbreaks, then keeping a diary may help you to identify them. A diary can also help you assess the severity and frequency of your herpes outbreaks, which may help you and your doctor decide what treatment approach is best for you. Record when you have a recurrence, what happened or what you did before it started, how you feel during it and how long it lasts.

You may find that, as the years go by, the number and/or the severity of your recurrences diminishes. The reasons for this decline are not known, but could include changes in your lifestyle, in your immune system, in the virus itself or in your improved ability to avoid certain trigger factors.

Information and counselling may help you to cope better with recurrent herpes outbreaks. People who make contact with a support group often say this is a turning point in coping with genital herpes in their life.

If your recurrences are frequent, painful and/or disrupt your life to a great extent, oral antiviral therapy can significantly reduce or suppress symptoms. There is no need for the virus to dominate your life.

Episodic and suppressive antiviral therapy

Episodic therapy

Treatment started at the first signs of a recurrence and taken for a few days is called episodic therapy. Episodic therapy is most effective when taken as soon as possible after symptoms appear, so you may find this approach useful if you can identify the early signs of a recurrence (e.g. tingling or pain in the skin).

Episodic therapy helps to relieve symptoms, and to shorten the duration of each outbreak, but has no effect on the frequency of attacks.

Suppressive therapy

Suppressive therapy involves taking an antiviral drug every day for prolonged periods of time, eg. a few months. Taken in this way, the virus is stopped from replicating and therapy can:

• reduce the number of outbreaks, or prevent them completely
  
• reduce the frequency asymptomatic shedding.
  

If you find the frequency of your outbreaks unacceptable, or you are finding it difficult to cope emotionally with having outbreaks of genital herpes, you may wish to tell your doctor, and discuss the use of suppressive therapy.

Is suppressive therapy suitable for me?

The use of suppressive therapy may vary and it is worth discussing with your doctor whether this option is appropriate for you. He or she may agree that suppressive antiviral therapy is suitable if you:

• find the frequency of your recurrences unacceptably high.
  
• have particularly severe, or long-lasting outbreaks.
  
• find recurrences of genital herpes are making you depressed, anxious or withdrawn, or the emotional upset is disrupting your social activities and/or sex life. Such feelings can themselves bring on a recurrence, resulting in a vicious cycle. Taking suppressive therapy, perhaps only for a few months, can help you break the cycle and give you a sense of control over the infection.
  
• experience severe pain (neuralgia) during recurrent episodes.
  
• have outbreaks that tend to occur during specific situations, for example, when you have exams or go on holiday, or you want to avoid spoiling a special event like a honeymoon, with a recurrence. Suppressive therapy around these situations should minimise the chances of a recurrence.
  
• have recurrences when you are starting a new relationship - suppressive therapy can provide a cushion of confidence.
  
• know that stress is a trigger factor for your recurrences, and you are going through a stressful period (e.g. a new job or a recent death in the family).
  
• have another illness that triggers a recurrence of herpes - a course of suppressive therapy may be appropriate until the other condition has resolved.

How long will I need to take the treatment?

If you and your doctor decide on suppressive therapy, you and he/she need also agree how long you will take it for before re-assessment. You can expect to feel in control of the infection after 6-12 months. If you are still having problems with recurrences, you and you doctor may then decide that you should continue suppressive therapy.

Will suppressive therapy make it easier to live with genital herpes?

Many people find being able to control their herpes boosts their sense of well-being and self-confidence. Even if only taken for a few months, suppressive therapy can help you to come to terms with depression and anxiety caused by recurrent genital herpes.

If you do find that your condition is difficult to cope with, it is important to seek expert support from your doctor or counsellor. You may also wish to join a patient support group in your area. Many people who make contact with a support group find it helpful. In addition, close friends or partners can continue to be an important source of support, and can help you over anxieties or depression caused by genital herpes.

Will suppressive therapy prevent me from passing on my infection?

Although we know that suppressive therapy reduces the likelihood of virus being shed during and between recurrences, it is not known whether it protects your sexual partners from HSV infection. A study to look into this question is ongoing but, until the results are known, it is best to continue with other strategies to minimise the risk of transmission (See 'Transmitting the infection' section in Genital Herpes: The Facts). It is advisable to discuss these with your partner. Your partner may wish to take a test to find out if he or she already carries either of the viruses that cause herpes. This can help you to decide what other protective strategies you need to adopt.

Condoms are not proven to protect against genital herpes transmission, but are considered helpful and it is advisable to use them. You are most at risk of passing on the infection when you have symptoms of a genital herpes outbreak. At these times you would be best advised to avoid sexual contact.

How effective is antiviral therapy?

Aciclovir

Aciclovir was the first effective antiviral agent and is still available, but it is less convenient than the newer therapies, valaciclovir and famciclovir. When aciclovir is taken as episodic treatment, it can reduce the severity (i.e. healing time and pain) of outbreaks of genital herpes and shorten their duration. In addition, aciclovir shortens the time during which the herpesvirus is detected on genital skin surfaces (virus shedding) - a time when the disease can be passed on to a sexual partner.(1)

Aciclovir can also be used as suppressive treatment to help reduce the frequency of outbreaks. In clinical trials it has been demonstrated to reduce the rate of recurrences from 11.4 to 1.8 per year.(2)

Valaciclovir

When used as episodic treatment, valaciclovir helps the sores heal faster, and shortens the period of pain during the outbreak. Valaciclovir also cuts down the time during which the virus is detected on skin surfaces.(3)

If you take valaciclovir as soon as you notice the first signs of a herpes outbreak - such as tingling, itching or redness - you may be able to completely prevent the development of painful blisters. In clinical tests, valaciclovir prevented the development of painful blisters and ulcers in one third more patients who took the drug within 24 hours of noticing the first symptoms of the outbreak, compared to those who took a dummy (placebo).(3)

When valaciclovir is used for suppressive therapy, clinical trials have proved it to prevent or delay up to 85% of herpes outbreaks, and 7-8 times more patients taking valaciclovir were recurrence - free compared with those taking placebo.(4,5)

Famciclovir

Famciclovir has been shown to reduce the time that outbreaks last when used as episodic treatment. The severity of pain with outbreaks is also decreased. Like valaciclovir and aciclovir, famciclovir also shortens the period during which virus is detected on genital surfaces.(6)

Suppressive therapy with famciclovir has been demonstrated to reduce outbreaks by 70-72%.(7,8) At the end of the study, 2-3 times more patients were recurrence-free taking famciclovir than taking placebo.

You should consult your doctor for further information about antiviral treatment for your particular situation.

How safe are antivirals?

Most people taking antiviral therapy tolerate it very well. A small number of people taking these therapies either as episodic or suppressive treatment have reported minor side-effects, such as headache, nausea and diarrhoea. There are no known serious side-effects associated with these treatments and there is virtually no interaction with other medications. However, if you do have a problem, tell your doctor immediately.

As with most medicines, antiviral therapies for genital herpes are not generally recommended for use during pregnancy. Some doctors may suggest the use of treatment if a woman is having her first ever episode of genital herpes during pregnancy. It is very important to discuss your specific circumstances with your doctor. For more information about genital herpes during pregnancy, please consult Herpes Simplex and Pregnancy.

How often do I have to take antiviral therapies?

Episodic therapy

Aciclovir should be taken five times a day for 5 days.(9,10) Valaciclovir and famciclovir are taken twice a day for 5 days when used as episodic treatment.(9-12)

Suppressive therapy

If you take aciclovir as suppressive therapy, you will need to take tablets between two and 5 times a day.(9,10) You only need to take valaciclovir once a day, or possibly twice a day if outbreaks are very frequent.(11,12) Famciclovir is taken two times every day.(13,14)

Are any other treatments effective against genital herpes?

A number of vaccines are currently being investigated for the treatment of herpes. It will be some years, however, before we know how well they work.

References
1. Nilson AE et al. Lancet 1982;2:571-573.
2. Mertz GJ et al. JAMA 1988;260:201-206.
3. Spruance SL et al. Arch Intern Med 1996;156:1729-1735.
4. Reitano M et al. J Infect Dis 1998;178:603-610.
5. Patel R et al. Genitourin Med 1997;73:105-109.
6. Sacks SL et al. JAMA 1996;276:44-49.
7. Mertz GJ et al. Arch Intern Med 1997;157:343-349.
8. Diaz-Mitoma F et al. JAMA 1998;<>280:887-892.
9. Glaxo Wellcome Aciclovir UK Summary of Product Characteristics
10. Glaxo Wellcome Aciclovir US Prescribing Information
11. Glaxo Wellcome Valaciclovir UK Summary of Product Characteristics
12. Glaxo Wellcome Valaciclovir US Prescribing Information
13. SmithKline Beecham Famciclovir UK Summary of Product Characteristics
14. SmithKline Beecham Famciclovir US Prescribing Information