Pharmacotherapy of Genital Herpes
PST 06106
Basic Pharmacotherapy
Session 17: Pharmacotherapy of Genital Herpes
Learning Tasks
By the end of this session students are expected to be able to:
Define genital herpes
Explain pathophysiology of genital herpes
Explain the clinical presentation of genital herpes
Outline diagnosis of genital herpes
Describe pharmacological treatment of genital herpes
Describe the monitoring of genital herpes
therapy
Activity: Buzzing
is Genital
Herpes?
Definition of Genital Herpes
Genital Herpes
Genital herpes is a common sexually transmitted infection caused by the herpes simplex virus (HSV).
Sexual contact is the primary way that the virus spreads.
There are two types of Herpes Simplex viruses; herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2).
HSV-1 is associated most commonly with oropharyngeal disease, and HSV-2 is associated most closely with genital disease;
However, each virus is capable of causing clinically indistinguishable infections in both anatomic areas.
Definition of Genital Herpes
Cont.….
Humans are the sole known reservoir for HSV.
Infection is transmitted via inoculation of virus from infected secretions onto mucosal surfaces (e.g., urethra, oropharynx, cervix, and conjunctivae) or through abraded skin.
The cycle of HSV infection occurs in five stages: primary muco-cutaneous infection, infection of the ganglia, establishment of latency, reactivation, and recurrent infection
Pathophysiology Of Genital Herpes
After viral inoculation, HSV infection is associated with cytoplasmic
granulation(condensed areas of cellular material that may be bounded by a membrane),
ballooning degeneration of
cells (cells undergoing this form of death increase in size(balloon),
and production of
mononucleated
giant
cells ( cells formed by fusion of monocytes/macrophage)
Initially, the cellular response is predominantly
polymorph nuclear,
followed by a lymphocytic response.
Replication occurs with viral spread to contiguous cells and peripheral sensory nerves. Latency then is established in sensory or autonomic nerve root ganglia.
Latency appears to be lifelong, interrupted only by reactivation of the viral infection.
It is unclear what factors are important in maintaining latency, but immune responses and emotional and physical stresses appear important in reactivating latent virus.
Clinical Presentation Of Genital Herpes
The signs and symptoms of genital herpes infection are
influenced by
many factors, including previous exposure to HSV, viral type, and host factors such as age and site of infection.
High percentage of initial and recurrent infections are asymptomatic,
Viral shedding can occur in the absence of apparent lesions or symptoms
A summary of the clinical presentation of genital herpes is provided in Table
Diagnosis Of Genital Herpes
A presumptive diagnosis of genital herpes commonly is made based on the presence of
dark-field negative
, vesicular, or ulcerative genital lesions.
A prior history of similar lesions or recent sexual contact with an individual with similar lesions also is useful in making the diagnosis
Viral culture. This test involves taking a tissue sample or scraping of the sores for examination in the laboratory
.
Diagnosis Of Genital
Herpes
Cont
….
Polymerase chain reaction (PCR) test. PCR is used to copy patient DNA from a blood sample, tissue from a sore or spinal fluid.
The DNA can then be tested to establish the presence of HSV and determine which type of HSV you have.
Blood test. This test analyzes a sample of blood for the presence of HSV antibodies to detect a past herpes infection.
Several serologic tests capable of distinguishing HSV-1 and HSV-2 antibodies are available.
These tests detect antibodies to type-specific HSV-1 and HSV-2 proteins gG-1 and gG-2, respectively
Activity
: Small Group Discussion
What
is the treatment of Genital Herpes?
Pharmacological Treatment of Genital Herpes
The most achievable goals in the management of genital herpes are to relieve symptoms and to shorten the clinical course, to prevent complications and recurrences, and to decrease disease transmission.
Although research has focused primarily on the treatment of active infection and suppression of recurrences, increasing emphasis is being placed on various approaches, including immunotherapy that might provide protection from disease transmission or possibly eliminate established latency.
.
Pharmacological Treatment of Genital Herpes
Oral formulations of acyclovir,
famciclovir
, and
valacyclovir
have demonstrated efficacy in reducing viral shedding, duration of symptoms, and time to healing of first-episode genital herpes infections, with maximal benefits seen when therapy is initiated at the earliest stages of infection
Pharmacological Treatment of Genital Herpes
Monitoring of Genital Herpes Therapy
Available antiviral compounds are of greatest benefit in patients experiencing first-episode primary infections, immunocompromised patients, and patients with frequent or severe recurrent infections.
Antivirals, however, are palliative and not curative, and patients receiving these agents should be monitored closely for adverse drug effects.
Discontinuation of suppressive therapy after 1 year should be considered to assess for possible changes in the patient’s intrinsic pattern of recurrence.
In many patients, decreases in recurrence rates and the severity of symptoms occur over time. However, it is also
preferred
to continue suppressive therapy indefinitely because it significantly reduces asymptomatic viral shedding, a potential benefit in reducing the risk of disease transmission to uninfected sexual partners
Key
Points
Genital
herpes is a common sexually transmitted infection caused by the herpes simplex virus (HSV).
Infection is transmitted via inoculation of virus from infected secretions onto mucosal surfaces (e.g., urethra, oropharynx, cervix, and conjunctivae) or through abraded skin
The signs and symptoms of genital herpes infection are
influencedby
many factors, including previous exposure to HSV, viral type, and host factors such as age and site of infection
Oral formulations of acyclovir,
famciclovir
, and
valacyclovir
have demonstrated efficacy in the treatment of genital herpes
Evaluation
What
is genital herpes?
What is the pathophysiology of
genital herpes?
What are the signs and symptoms of genital herpes?
How is the treatment of genital herpes?
References
Wells
BG,
DiPiro
J,
Schwinghammer
T (2013),
Pharmacotherapy Handbook
(6
th
Ed). New York, NY: McGraw-Hill.
DiPiro
JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey ML, (2008):
Pharmacotherapy: A Pathophysiologic Approach
(7
th
ed
): New York, NY: McGraw-Hill.
Katz M D.,
Matthias KR.,
Chisholm-Burns M A.,
Pharmacotherapy(2011)
Principles & Practice Study Guide: A Case-Based Care Plan Approach
:
New York, NY: McGraw-Hill.
Schwinghammer
TL, Koehler JM (2009)
Pharmacotherapy Casebook: A Patient-Focused Approach
(7
th
ed
): New York, NY: McGraw-Hill.
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