Pharmacotherapy of Genital Herpes – PST06106 Basic Pharmacotherapy
NTA Level 6 • Semester 1 • PST06106 Pharmacotherapy of Genital Herpes Basic Pharmacotherapy • Source Session/Topic 17 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. 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 • What 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,