Transcript
8
Antiviral and Antifungal Agents
Educational Objectives
After reading this chapter, the reader should be able to:
1. illustrate the pathophysiology of herpex simplex viruses.
2. List various antiherpetic drugs.
3. Describe the appropriate dental management of patients with herpes labialis.
4. Describe the pharmacology of currently approved drugs used in the treatment of HIV infection.
5. Describe selected drugs with adverse effects related to dentistry and how to manage them.
6. Discuss dental implications of patients taking anti-HIV drugs.
7. List the patients who are higher risk for fungal infections.
8. List common antifungal agents used to treat oral infections.
9. List common drug interactions of systemic antifungal agents.
Lecture Outline
I. HIV/AIDS
A. Caused by a transmissible RNA retrovirus known as HIV type 1.
1. Replication of viral RNA into proviral DNA.
2. T4-lymphocytes involved; opportunistic infections: tuberculosis, fungal infections (oral candidiasis, esophageal candidiasis), Pneumocystis jiroveci (formerly Pneumocystis carinii), pneumonia (PCP), recurrent bacterial pneumonia, diarrhea, meningitis, and cancers such as Kaposi’s sarcoma and non-Hodgkin’s lymphoma.
B. Principles of HIV pharmacotherapy.
1. Viral load indicator for start of drug treatment.
2. Drugs are expensive.
3. Resistance develops.
C. Classification of drugs for HIV/AIDS.
1. Antiretroviral drugs block phases of HIV replication cycle.
2. Highly active antiretroviral therapy (HAART).
a. Four drugs used concurrently.
b. Goal to reduce plasma level of HIV.
c. Reduces development of resistance.
3. Classes of antiretroviral drugs.
a. Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs/NtRTIs).
b. Non-nucleoside reverse transcriptase inhibitors (NNRTIs).
c. Protease inhibitors (PIs).
d. Fusion inhibitors.
4. Pharmacological treatment of oral opportunistic infections.
a. Fungal infections
b. Ulcers
c. Intraoral pain
d. Xerostomia
5. Adverse effects of drugs
a. Oral
b. Dentaldrug interactions
II. Herpes Simplex Viruses (HSV)
A. Family of DNA viruses.
B. Infect mucosal membrane, skin, genitals.
C. Transmitted by direct physical contact with infected patients.
D. Serotypes, HSV-type 1.
1. Primary herpetic gingivostomatitis (Figure 7–1)
a. First exposure.
b. Children, adults affected.
c. Adults: antibodies to HSV-1.
d. Painful intraoral vesicles, generalized gingivitis, high fever, malaise, fatigue.
e. Transmitted by infected saliva.
f. Self-limiting 10–14 days.
g. Palliative treatment.
i. Acetaminophen.
ii. Do not use aspirin.
2. Recurrent herpes simplex virus infection.
a. Herpes labialis.
b. Intraoral sites, nonmovable mucus.
c. Most resolve in 10–14 days.
d. Transmissible.
e. Painful and symptomatic.
f. Precipitating factors.
i. Immunosuppression (e.g., HIV/AIDS).
ii. Emotional stress.
iii. Physical.
g. Antiviral agents.
i. Risks versus benefits (e.g., antivirals do not cure).
ii. Inhibit DNA synthesis.
iii. Topical.
(a) Acyclovir (Zovirax) 5% cream/ointment.
(b) Penciclovir 1% (Devavir) cream.
(c) Valacyclovir (Valtrex).
(d) Various OTC products.
(e) Docosanol (Abreva) cream.
iv. Systemic (e.g., oral acyclovir is recommended in immunocompromised [HIV+]).
III. Antifungal Agents
A. Caused by molds or yeasts.
B. Candidia sp. in the oral pharyngeal region.
C. Mycosis.
1. Systemic.
2. Subcutaneous.
3. Superficial or mucocutaneous.
a. Location.
i. Skin.
ii. Oral mucous membranes (oral cavity).
b. Etiology: Candida albicans.
D. Chronic atrophic candidiasis (denture sore mouth).
1. Red lesion under denture.
2. Treatment.
a. Antifungals.
i. Troches, oral suspension.
ii. Vaginal suppository tablets.
(a) Less sugar content.
(b) Psychological component.
b. Keep denture out at night and clean to prevent reinfection.
E. Acute pseudomembranous candidiasis (thrush).
1. White plaque that easily wipes off with gauze leaving a raw, red, bleeding connective tissue surface.
F. Patient population.
1. Immunocompromised.
a. HIV/AIDS.
b. Older adults, pregnant women, children, newborns.
c. Antibiotics for bacterial infections; superinfection.
d. Steroids: systemic or inhalers.
e. Poorly fitting dentures.
2. Treatment; antifungal agents.
a. Topical.
i. Nystatin.
ii. Clotrimazole.
b. Systemic (more severe cases): fluconazole, ketoconazole.
c. Drug interactions.
3. Systemic and subcutaneous infections not related to dentistry.Teaching Tips
1. Impress upon the students that herpes cannot be cured.
2. Review current topics on antiretroviral agents (HAART). Have the class report on its findings.
3. Create a Jeopardy board for students to learn the various drugs used in the treatment of HIV infection.
4. Impress upon students the importance of knowing how to provide oral care to a patient with HIV/AIDS.
5. Impress upon the students how many immunocompromised patients develop oral conditions/lesions that are treated in the dental office.
6. Create flash cards for students to learn the adverse oral effects of antiretroviral agents.
7. Explain to students the importance of learning that candidiasis infections under maxillary dentures are rather common because patients do not remove dentures at night to clean them (e.g., especially common with patients who are susceptible to “superinfections”).
8. Explain the importance of informing patients to take supplemental acidophilus or yogurt when taking a broad-spectrum antibiotic to avoid superinfections (e.g., candidiasis) in the mouth and elsewhere in the body.
9. Impress upon the students to instruct patients using an anti-asthmatic inhaler to rinse their mouths with water after every dose to avoid the development of thrush.
10. Explain the importance of checking for drug interactions when an antifungal agent is prescribed to a patient.
Factoids
1. About 45 million Americans are infected with genital herpes.
2. HSV-1 is becoming a major cause of genital herpes.
3. Of the more than 200,000 known species of fungi, fewer than 200 infect humans. About 90% of these infections are caused by just a few dozen species.
4. “Azole” suffix is used for fungal drugs (e.g., fluconazole, clotrimazole).
Discussion Questions
1. Discuss the advantages of HAART in the pharmacology of HIV infection.
2. Discuss dental hygiene oral care with a patient who has HIV/AIDS.
3. Distinguish between the two types of herpes infection.
4. Discuss the drugs used in the management of HSV-1 and HSV-2.
5. Discuss the recommended antiviral therapy for immunocompromised and immunocompetent patients with herpes infections.
6. Discuss the different ways that antifungal agents are used in the treatment of oral candidiasis (e.g., dissolving vaginal tablets in the mouth).
7. Discuss the difference between topical and systemic antifungal agents.
Classroom Activities 1. Have the students in the clinic identify patients who may have an oral fungal infection (e.g., under maxillary dentures). In the classroom, discuss the different drug regimens for treatment.
2. Divide students in groups and have them make flash cards for the drugs used in the management of herpes labialis.
3. Have students visit the cdc web site at phil.cdc.gov and review the information and pictures posted. Discuss with class.
4. Have students make instruction sheets for patients listing the various prescription and OTC drugs used for the therapeutic and palliative treatment of herpes labialis. Include instructions on how to take the medicine (e.g., topical Orabase should be dabbed on rather than rubbed).
5. Have students make a list of OTC analgesic products for the pain relief of herpes labialis.
Multimedia Found in the PowerPoint Lecture OutlineAnimations
1. Acyclovir mechanism of action.
2. Zidovidine mechanism of action.
3. Interferon mechanism of action.
4. Saquinavir mechanism of action.
Videos
2. Fluconazole mechanism of action.
Video
1. Herpes.
© 2013 by Education, Inc.
Weinberg, Instructor’s Resource Manual for Oral Pharmacology for the Dental Hygienist, 2nd Edition
