Australian Herpes Management Forum

Managing Genital Herpes

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Compiled by the Board of the Australian Herpes Management Forum (AHMF)

Genital herpes is under-recognised and under-treated

More than three-quarters of people with genital herpes simplex virus infection do not receive appropriate therapy for their condition because the infection has not been recognised or properly diagnosed.

This guideline provides essential information on the management of genital herpes, particularly on available therapies and relevant PBS information.

Figure 1: Percentage of genital herpes symptoms

Why is genital herpes often unrecognised

Many clinicians are under the impression that genital herpes has a characteristic appearance, comprising easy to recognise blisters or ulcers. However, in reality, the so-called ‘typical’ signs of herpes are not that common. The recurrent episodes of viral shredding may be completely asymptomatic or associated with a wide variety of signs and symptoms such as erythema, small fissures, excoriated skin and burning or itching. It is also important to recognise that owing to the distribution of sacral sensory nerves, recurrences may occur anywhere below the waist; particularly common sites are on the buttocks, lower back, thighs and around the anus.

What do clinicians need to accomplish?

When seeing a new patient with suspected genital herpes the clinician should establish a working diagnosis for the immediate management of the patient and confirm the diagnosis by taking a swab. It is generally appropriate to screen for potentially co-existing sexually transmitted infections (STIs). It may also be appropriate to suggest that the patient's sexual partners are evaluated. Finally, the health care provider should counsel and educate the patient, both about the virus and the psychosocial issues associated with it. AHMF has guidelines addressing counselling and communication skills for patients with genital herpes and preventing the sexual transmission of genital herpes.

The AHMF also produces guidelines on diagnosing herpes simplex viruses and the use of type specific serology for diagnosing genital herpes.

Antiviral Management

Many patients will not require antiviral therapy. Despite this, the potential benefits should be discussed with all patients. As many patients are unaware of the treatment options available to them, the responsibility lies with the clinician to provide patients with sufficient information to enable them to participate fully in management decisions. Once the patient is fully informed about the options available, the patient and clinician together can then agree upon a management strategy.

There are two basic approaches to antiviral management of the patient with recurrent genital herpes. One is ‘episodic’ oral antiviral therapy, where the patient self-administers antiviral therapy as soon as they experience a recurrence. The other is ‘suppressive’ (preventative) antiviral therapy, or ‘suppression’, where the patient takes antiviral therapy continuously to prevent recurrences. The AHMF has a clinical guideline on the suppression of genital herpes.

Episodic therapy may decrease the duration of lesions by one to one and a half days and some patients may find this effect clinically significant. Episodic therapy may be appropriate for those with few or irregular recurrences. There is also some evidence that recurrences be aborted if antiviral therapy is begun during the prodrome (warning signs). Suppressive therapy can reduce the number of recurrences, and virus shedding, by 85-90%.

The decision whether to receive episodic antiviral therapy, suppressive antiviral therapy or no therapy at all should be made by the patient in consultation with the health care provider. The health care provider's main role is to educate and counsel so that the patient is able to make an informed choice.

Return control of the infection to the patient

Patients managed by episodic antiviral therapy can start therapy themselves each time they detect the first signs of a recurrence. Self-initiation allows each recurrence to be treated more expeditiously than if a physician has to be consulted.

Education directed at recognition of early signs and symptoms, including prodromal symptoms, is very important. Allowing patients to self-initiate treatment without having to go back to the physician also returns control of the infection to the patient.

Antiviral Therapies

There are three drugs currently available for the treatment of herpes simplex virus: aciclovir, famciclovir and valaciclovir. All three drugs prevent replication of herpes simplex virus by inhibiting the synthesis of viral DNA. They are active only in herpes virus-infected cells, making them extremely safe and well tolerated. Aciclovir's only drawback is poor bioavailability, i.e. only a proportion (about one fifth) of each dose is absorbed. Famciclovir is the oral pro-drug of penciclovir, which has a similar, but not identical, mechanism of action to aciclovir. Famciclovir is well absorbed orally, making twice daily oral therapy possible. Because valaciclovir is metabolised to aciclovir in vivo, it has exactly the same mechanism of action as aciclovir. Valaciclovir has the advantage over aciclovir in that it is approximately 54 per cent absorbed by the mouth, hence making lower doses and/or less frequent dosing possible. Valaciclovir has also been shown to reduce the risk of transmission.

The following table provides a comprehensive list of the available therapies with the dose required to treat initial and recurrent episodes of genital herpes as well as for suppressive therapy. In some instances it may be appropriate to vary doses and duration of therapy from those given here. For these cases, the AHMF recommends that advice be sought from a specialist.

Treatment of Genital Herpes Simplex Infections

Pharmaceutical Benefits Schedule Listing

The current requirements for authority prescription of aciclovir, famciclovir and valaciclovir for the management of genital herpes are as follows:

Moderate to severe initial genital herpes:

Microbiological confirmation of diagnosis (viral culture, antigen detection or nucleic acid amplification by PCR) is desirable but need not delay treatment.

Episodic treatment or suppressive therapy of moderate to severe recurrent genital herpes:

Microbiological confirmation of diagnosis (viral culture, antigen detection or nucleic acid amplification by PCR) is required but need not delay treatment.

For further information the AHMF recommends that prescribers consult the PBS.

What do patients with genital herpes want from their clinicians?

• To be given accurate information;
• To be involved in decisions about the management strategies for their disease;
• To be provided with the best treatment reflecting current best practice;
• Not to be judged or patronised;
• To be referred to other specialists when appropriate (eg. for counselling).

Bibliography

Brady, RC, Bernstein DI. Treatment of herpes simplex virus infections. Antiviral Research 2004;61(2):73-81

Brentjens, MH, Yeung-Yue KA, Lee PC, Tyring SK. Recurrent genital herpes treatments and their impact on quality of life. Pharmacoeconomics 2003.21(12):853-863

Corey L, Wald A, Patel R, et al. Once-daily valacyclovir to reduce the risk of transmission of genital herpes. New England Journal of Medicine 2004;350(1):11-20

Cunningham AL, Taylor R, Taylor J, Marks C, Shaw J and Mindel A. Prevalence of infection with herpes simplex virus types 1 and 2 in Australia: a nationwide population based survey. Sexually Transmitted Infections 2006:82(2):164-8

Donovan, B. Sexually transmissible infections other than HIV. Lancet 2004;363(9408):545-556

Kimberlin DW, Rouse DJ. Clinical practice: Genital Herpes. New England Journal of Medicine 2004.350(19):1970-1977.

Disclaimer

The AHMF have made considerable efforts to ensure the information upon which this guideline is based reproduces the evidence as accurately as possible. Users of this guideline are strongly recommended to confirm that the information contained within it, especially drug indications, is correct by way of independent sources, as this guideline does not indicate an exclusive course of action or serve as a standard of medical care. The AHMF accepts no responsibility for any inaccuracies, information perceived as misleading, or success of any treatment regime detailed in this guideline.