A double-strength antiviral which halves the amount of daily medication required by patients with poor immunity to treat or prevent outbreaks of genital herpes, and treat shingles has been launched.
See below interview for leading Australian sexual health experts to learn how patients receiving chemotherapy or radiotherapy, organ transplant recipients or those with HIV infection who have genital herpes or shingles may benefit from the reimbursed listing of this medication.
The stats
One in eight Australians who have been sexually active have genital herpes.
The prevalence of the herpes virus is three times more common in men with HIV (more than 60% have the virus).
Genital herpes recurs easily, may be passed on even without visible blisters or lesions, and can increase the risk of transmitting HIV.
Shingles is a rash or outbreak of blisters on the skin caused by reactivation of the varicella zoster virus. It affects people who have had chickenpox.
People with poor immunity often suffer more frequent and severe, longer-lasting and more painful attacks of genital herpes and shingles than the rest of the community.
People with HIV have a 30% higher risk of developing shingles compared to people who are HIV negative.
Reducing the total number of genital herpes outbreaks minimises transmission of both the HIV and herpes simplex viruses to other people.
Herpes and shingles Q&A with Dr Darren Russell, Director of Sexual Health, Cairns Base Hospital, QLD
What are the two most important key messages about herpes infection that immunocompromised patients need to know?
The key messages for people who are immunocompromised are: 1. Prevention is better than cure, so if you can suppress the virus, that's much better than waiting for an outbreak of sores and then trying to control it.
2. If you are getting blisters or sores on your genitals, see your doctor as soon as possible to get a diagnosis so you can be treated.
Why is the herpes simplex virus type 2 (HSV 2) infection twice as prevalent in people with HIV compared with those who are not infected with HIV?
There could be two main reasons for this. The first is statistical. People who contract HIV are often very sexually active and are therefore more likely to have other STIs. Often they have genital herpes before they contract HIV.
The other possibility is theoretical. People with HIV have a poorly functioning immune system, so they may be more likely to contract genital herpes than people who can fight off the infection because they have a healthy immune system.
Why is it important to control HSV if you are immunocompromised? What's the link between HIV and HSV?
If you have HSV and your immune system is weakened (as with HIV), you are more likely to pass on genital herpes to other people than someone whose immune system is healthy, because you will shed more of the HSV virus. And if you have HSV, you're also more likely to shed more of the HIV virus as well. If you have herpes blisters because of HSV, these lesions provide a portal of entry and exist for the HIV virus. [HSV can be reactivated and passed on to other people even when you don't notice any blisters or lesions].
There's also some evidence to show that treatment for HSV may lower the viral load of HIV, so it may have a small impact on controlling the HIV virus. Some antiviral therapy that prevents the reactivation of HSV has also been shown to slow the progression of HIV.
What effect does a weakened immune system have on genital herpes?
There's a link between reactivation of the herpes virus and weakness of the immune system which is measured by CD4 cell count. People with a low CD4 cell count experience more episodes of genital herpes and they can be more severe and more prolonged than in the general population, if they don't take antiviral treatment to control the herpes virus.
What is the key advantage for immunocompromised patients of the recent PBS reimbursement of Famvir® (famciclovir) 500 mg tablets?
For those people with a lower CD4 cell count who need to take a higher dose of antiviral, the 500 mg tablet is much more convenient. Now they need only take two tablets a day instead of four. And given that the new treatments for HIV have reduced the number of tablets needed to only two or three a day, patients will definitely appreciate the difference of taking less medication.
Famvir is indicated for episodic and suppressive therapy for genital herpes in immunocompromised patients. How would you use it?
For patients with HIV, we prefer them to be on long-term, suppressive treatment. Some patients don't like to take tablets all year round, but as doctors, we prefer long-term use. This also helps to reduce their risk of shingles, which is really important, particularly among those with low CD4 cell counts.
What is the effect of a weakened immune system on shingles?
People with a weakened immune system, such as those receiving chemotherapy or radiotherapy, those who have had an organ transplant, or those who have HIV infection, are often at risk of disseminated herpes zoster, with multi-dermatomal shingles that can be extremely painful. They're also at risk of more frequent and prolonged attacks of shingles.
What are the advantages of taking Famvir 500 mg within 72 hours of rash onset to treat herpes zoster in immunocompromised patients?
If your immune system is weak, treating herpes zoster within 72 hours of the onset of a rash helps to prevent many of the complicating factors of shingles - you're less likely to get prolonged attacks, less pain and scarring and less prevalence of post-herpetic neuralgia. There's also evidence that even in the healthy immune system, if you wait for a week before treatment, it's costly and not as effective. Most benefit is gained within three days of the rash onset. If you waited a week to treat someone who's immunocompromised, they would probably have almost passed away.
Dr Darren Russell MBBS FRACGP DipVen FAChSHM
Dr Darren Russell is the Director of Sexual Health at Cairns Base Hospital.
He was previously a senior lecturer in the Department of Public Health at The University of Melbourne and a Consultant Sexual Health Physician at the Royal Melbourne Hospital and Melbourne Sexual Health Centre.
Dr Russell has an interest in men's health, Indigenous sexual health, and genital herpes infections. He has been involved in research regarding genital herpes and is a co-editor of the textbook, 'Sexual Health Medicine', and a joint author of 'Talking with clients about sex'.
More on Genital Herpes - www.femail.com.au/genitalherpes.htm