Nursing Pharmacology:  Antiviral Drugs

• Antiviral Drugs

  • Anti-viral drugs with activity against HIV (Human Immunodeficiency Virus)

    • HIV-1 Pathophysiology/Pathogenesis:  HIV Disease Presentations

      HIV Effects on the Gastrointestinal System:

      • Secondary bacterial, viral, and protozoal infections of the intestines can cause diarrhea, abdominal pain and elevated temperature in HIV-infected individuals.² 

        • Bacteria possibly responsible for secondary G.I. tract infections include enteric pathogens such as Salmonella, Shigella and Campylobacter.

          •  

            Salmonella Typhimurium (red)⁸

            Rocky Mountain Laboratories, NIAID, NIH (public domain photo) Color-enhanced scanning electron micrograph showing Salmonella Typhimurium (red) invading cultured human cells. http://commons.wikimedia.org/wiki/File:SalmonellaNIAID.jpg

          •  

            Shigella:  Shigellosis¹⁰

            CDC:  "Shigellosis is an infectious disease caused by a group of bacteria called Shigella.  Most who are infected with Shigella develop diarrhea, fever and stomach cramps starting a day or two after they are exposed to the bacteria." http://www.cdc.gov/shigella/

          •  

            Campylobacter jejuni¹¹

            De Wood, Pooley C Agriculture Research Service (US Dept. of Agricuture) This scanning electron microscope image illustrates the characteristic corkscrew or spiral cellular shape. http://commons.wikimedia.org/wiki/File:ARS_Campylobacter_jejuni.jpg

             

        • Patients with untreated HIV exhibit about a 20-fold increased risk of Salmonella typhimurium (S. typhimurium).²

      • Patient clinical presentations may include nonspecific symptoms such as fever, fatigue, anorexia and malaise with a several week duration.²

        • Diarrhea is common and the specific diagnosis follows from blood and stool culture.² 

          • Long-term pharmacological treatment with ciprofloxacin may be recommended.

          • HIV-infected individuals exhibit increase incidence of typhoid fever in those geographical regions exhibiting significant typhoid presence.

          • Shigella (especially Shigella flexneri) is another bacteria causing severe intestinal disease in HIV patients.

            • In this group as many as half of patients develop bacteremia.

          • Campylobacter infections also are noted with increased frequency in HIV-infected individuals.

            • The most frequently isolated strain is Campylobacter jejuni (C. Jejuni).

              • These patients present with crampy abdominal pain, bloody diarrhea and fever; furthermore, stool analysis shows fecal leukocyte presence.

                • Systemic infection may also occur with bacteremia noted in up to about 10% of infected patients.

                • Campylobacter jejuni strains are usually sensitive erythromycin.

          • Infection with Mycobacterium avium complex (MAC) may also present with abdominal pain and diarrhea.²

            •  

              "Mycobacterium avium-intracellulare infection of lymph node in patient with AIDS"⁷

              CDC/ Ewing Jr, EP Mycobacterium avium-intracellulare infection of lymph node in patient with AIDS.7 Ziehl-Neelsen stain., 1983 (CDC Public Health Image Library, photo ID# 965)7  http://phil.cdc.gov/phil/details.asp

           

          • In as many as 50% of diarrhea cases reported in HIV-infected individuals pathogens are not found, even after extensive diagnostic evaluation.⁵ 

            • As a result, this condition is described as AIDS enteropathy, characterized by:

              • Chronic diarrhea

              • Malnutrition and

              • Wasting.

            • Possibly such chronic diarrhea may be due to not yet identified pathogens or even by noninfectious causes including lymphoma.

            • Furthermore, pathogen-negative diarrhea may be due to HIV directly, infecting the enterocyte and gut lymphoid tissue.⁵

            • Wasting noted in HIV-infected patients describes a body mass index of <18.5 kg/m².^5,13 

              • "AIDS Wasting"¹²

                Attribution: Giese J Benson P AIDS Wasting https://www.youtube.com/watch?v=0d5_bXUd1Mg  (11/2009) HIV/AIDS YouTube Channel:  https://www.cdc.gov/hiv/basics/whatishiv.html (CDC)

              • Weight loss and wasting are still noted in patients being treated for HIV infection and weight loss of 3% or more appears associated with increased mortality.

              • In untreated HIV infection several factors appear important in wasting.

                • Factors leading to increased caloric requirements in this setting include not only increased metabolic requirements of HIV replication but also metabolic requirements associated with opportunistic infections and fever.

                  • Reduced oral intake may occur as a result of nausea, anorexia, odynophagia, dysphasia as well as chronic diarrhea.

                    • Additional factors include food insecurity, dementia or depression.

                  • Nutrient malabsorption from the small intestine or pancreatic disease worsens weight loss.⁵

              • Therefore in the HIV-infected patient even an increase in caloric intake may be insufficient to compensate for nutrient loss in stool.⁵ 

              • A number of approaches may be helpful in managing wasting and weight loss.

                • Such strategies include HIV treatment, treatment of opportunistic disease, frequent albeit small meals combined with appetite stimulants and/or other agents.

                • Appetite stimulants include: megestrol acetate and dronabinol)

                • Anabolic steroids (testosterone, oxandrolone, nandrolone)

                • Recombinant HGH (human growth hormone)

              • Combinations of these approaches along with HIV replication control may result in improved nutritional status and weight.⁵

References

Flexner C Antiretroviral Agents and Treatment of HIV Infection, Chapter 59  in Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12th edition (Brunton LL Chabner BA Knollmann BC, eds; Brunton LL, ed; Blumenthal DK  Murri N Hilal-Dandan R, assoc eds, Knollmann BC, consulting ed, on-line edition) The McGraw-Hill Companies, 2011. Fauci AS Lane HC Chapter 189, Human Immunodeficiency Virus Disease:  AIDS and Related Disorders, in Harrison's Online   (Dan L. Longo, Anthony S. Fauci, Dennis L. Kasper, Stephen L. Hauser, J. Larry Jameson, Joseph Loscalzo, Eds.),  Harrison's Principles of Internal Medicine, 18th edition, The McGraw-Hill Companies, Inc. 2012. Longo DL Fauci AS  188, The Human Retroviruses, in Harrison's Online   (Dan L. Longo, Anthony S. Fauci, Dennis L. Kasper, Stephen L. Hauser, J. Larry Jameson, Joseph Loscalzo, Eds.),  Harrison's Principles of Internal Medicine, 18th edition, The McGraw-Hill Companies, Inc. 2012. Woster PM Chapter 43:  Antiviral Agents and Protease Inhibitors in Foye's Principles of Medicinal Chemistry 6e, Lemke, TL Williams DA, eds; Roche VG Zito SW, asst eds) Wolters Kluwer|Lippincott Williams & Wilkins 1214, 2008. Knox TA Wanke C Gastrointestinal Manifestations of HIV and AIDS  Chapter 397, pp 2196-2199 Goldman's Cecil Medicine 24e (Goldman L and Schafer AI, eds) Elsevier/Saunders, 2012. Volberding PA Gastrointestinal manifestations of HIV:  Candida Esophagitis  University of California San Francisco. U.S.  Department of Veterans Affairs Image Library. http://www.hiv.va.gov/provider/image-library/gastrointestinal.asp?post=1&slide=188 CDC/ Ewing Jr, EP Mycobacterium avium-intracellulare infection of lymph node in patient with AIDS.  Ziehl-Neelsen stain., 1983 (CDC Public Health Image Library, photo ID# 965) http://phil.cdc.gov/phil/details.asp Rocky Mountain Laboratories, NIAID, NIH (public domain photo) Color-enhanced scanning electron micrograph showing Salmonella Typhimurium (red) invading cultured human cells. http://commons.wikimedia.org/wiki/File:SalmonellaNIAID.jpg Li, J A 3D biomedical animation depicting HIV infection in the gastrointestinal tract. 2010. https://www.youtube.com/watch?v=fhwtNfRWcr0  CDC (Centers for Disease Control)  Shigella:  Shigellosis http://www.cdc.gov/shigella/ De Wood, Pooley C Agriculture Research Service (US Dept. of Agricuture) Campylobacter jejuni http://commons.wikimedia.org/wiki/File:ARS_Campylobacter_jejuni.jpg Demitrov AIDS Wasting https://www.youtube.com/watch?v=0d5_bXUd1Mg Reuter GS The HIV Wasting Syndrome NEJM Journal Watch , November 1, 1996 http://www.jwatch.org/ac199611010000001/1996/11/01/hiv-wasting-syndrome

 

Disclaimer

This Web-based pharmacology and disease-based integrated teaching site is based on reference materials, that are believed reliable and consistent with standards accepted at the time of development. Possibility of human error and on-going research and development in medical sciences do not allow assurance that the information contained herein is in every respect accurate or complete. Users should confirm the information contained herein with other sources. This site should only be considered as a teaching aid for undergraduate and graduate biomedical education and is intended only as a teaching site. Information contained here should not be used for patient management and should not be used as a substitute for consultation with practicing medical professionals. Users of this website should check the product information sheet included in the package of any drug they plan to administer to be certain that the information contained in this site is accurate and that changes have not been made in the recommended dose or in the contraindications for administration.  Advertisements that appear on this site are not reviewed for content accuracy and it is the responsibility of users of this website to make individual assessments concerning this information.  Medical or other information  thus obtained should not be used as a substitute for consultation with practicing medical or scientific or other professionals.