You are in: eMedicine Specialties > Neurology > Neurological Infections HIV-1 Associated Progressive PolyradiculopathyArticle Last Updated: Mar 14, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Niranjan N Singh, MD, DNB, Fellow in Neurophysiology, Department of Neurology, St Louis University School of Medicine Niranjan N Singh is a member of the following medical societies: American Academy of Neurology Coauthor(s): Mandeep Garewal, MD, Staff Physician, Department of Neurology, Saint Louis University School of Medicine; Florian P Thomas, MD, MA, PhD, Drmed, Director, Spinal Cord Injury Unit, St Louis Veterans Affairs Medical Center; Director, National MS Society Multiple Sclerosis Center; Associate Program Director, Professor, Department of Neurology and Psychiatry, Associate Professor, Institute for Molecular Virology, and Department of Molecular Microbiology and Immunology, St Louis University; Sofia Yahya, MD, Staff Physician, Department of Psychiatry, Barnes-Jewish Hospital, Washington University School of Medicine Editors: Daniel H Jacobs, MD, Clinical Associate Professor, Department of Neurology, University of Florida; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Glenn Lopate, MD, Associate Professor, Department of Neurology, Division of Neuromuscular Diseases, Washington University School of Medicine; Chief of Neurology, St Louis ConnectCare, Consulting Staff, Barnes Jewish Hospital; Matthew J Baker, MD, Consulting Staff, Collier Neurologic Specialists, Naples Community Hospital; Nicholas Y Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff, Neurology Specialists and Consultants Author and Editor Disclosure Synonyms and related keywords: acquired immunodeficiency syndrome, AIDS, cytomegalovirus, CMV, CMV polyradiculopathy, HIV infection, CMV-associated progressive polyradiculopathy INTRODUCTIONSection 2 of 10
  BackgroundThis condition occurs late in the course of HIV infection, unlike inflammatory demyelinating polyradiculoneuropathies in HIV, which usually occur earlier in the course of disease. Progressive polyradiculopathy in HIV infection coincides with a very low CD4 lymphocyte count, commonly less than 200 cells/µL. PathophysiologyPolyradiculopathy typically results from cytomegalovirus (CMV) infection. CMV co-infection of the retina and other sites is common. An idiopathic form exists, which has a better prognosis than the CMV-related form. Less common causes of polyradiculopathy in HIV infection include spinal forms of lymphoma and several CNS infections such as tuberculosis, syphilis, cryptococcosis, herpes simplex virus type 2, varicella virus, and toxoplasmosis. Mortality/MorbidityCMV polyradiculopathy is rapidly fatal without treatment. Treatment with foscarnet or ganciclovir may improve or stabilize the condition. CLINICALSection 3 of 10
HistoryPolyradiculopathy presents as a cauda equina syndrome.
Physical
DIFFERENTIALSSection 4 of 10
Acute Inflammatory Demyelinating Polyradiculoneuropathy Amyotrophic Lateral Sclerosis Chronic Inflammatory Demyelinating Polyradiculoneuropathy HIV-1 Associated Acute/Chronic Inflammatory Demyelinating Polyneuropathy HIV-1 Associated Opportunistic Infections: CNS Cryptococcosis HIV-1 Associated Opportunistic Infections: CNS Toxoplasmosis HIV-1 Associated Opportunistic Neoplasms: CNS Lymphoma Primary CNS Lymphoma Tuberculous Meningitis
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| Drug Name | Ganciclovir (Cytovene, Vitrasert) |
|---|---|
| Description | Synthetic guanine derivative, acyclic nucleoside analog of 2'-deoxyguanosine that inhibits viral replication in vitro and in vivo. Levels of ganciclovir-triphosphate are as much as 100-fold greater in CMV-infected than uninfected cells, possibly owing to preferential phosphorylation in infected cells. |
| Adult Dose | Initial dosing: 5 mg/kg IV bid for 14 d Maintenance IV: 5 mg/kg qd for 5-7 d/wk Maintenance PO: 500 mg q4h or 1 g tid for life |
| Pediatric Dose | <3 months: Not established >3 months: Administer IV regimen as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | Cytotoxic drugs such as dapsone, pentamidine, flucytosine, vincristine, vinblastine, Adriamycin, amphotericin B, trimethoprim/sulfamethoxazole combinations, or other nucleoside analogs may have additive toxicity in replication of rapidly dividing cell populations (eg, bone marrow, spermatogonia, germinal layers of skin and GI mucosa); consider concomitant use of these drugs only if potential benefits outweigh risks Imipenem-cilastatin may cause generalized seizures—use them concurrently only when potential benefits outweigh risks Either cyclosporine or amphotericin B may increase serum creatinine; probenecid decreases renal clearance May increase bioavailability of didanosine when administered either within 2 h prior to or simultaneously—conversely, didanosine may decrease steady-state bioavailability of ganciclovir if administered within 2 hours prior to ganciclovir but not when 2 drugs administered simultaneously Zidovudine may decrease bioavailability—conversely, ganciclovir may increase bioavailability of zidovudine Since both ganciclovir and zidovudine can cause granulocytopenia and anemia, combination therapy at full dosing may not be possible |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Clinical toxicity includes granulocytopenia, anemia, and thrombocytopenia Since oral form associated with higher rate of CMV retinitis progression than IV form, use only when benefits outweigh risks, such as in advanced HIV disease Administration should be accompanied by adequate hydration, since drug cleared by kidneys; use with caution in patients with renal failure, since half-life and plasma/serum concentrations may be increased Dosages > 6 mg/kg IV have resulted in increased toxicity; likely that more rapid infusions result in increased toxicity Initially, reconstituted solutions of IV form have high pH of 11; phlebitis or pain may occur at site of IV infusion despite further dilution in IV fluids To reduce risk of photosensitization (photoallergy or phototoxicity), patients should reduce exposure to UV light until tolerance develops |
| Drug Name | Foscarnet (Foscavir) |
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| Description | This organic analog of inorganic pyrophosphate inhibits viral replication in vitro. Antiviral activity due to selective inhibition at pyrophosphate-binding site on virus-specific DNA polymerases at concentrations that do not affect cellular DNA polymerases. Patients who show poor clinical response or have persistent viral excretion may be developing resistance. Patients who tolerate well may benefit from earlier initiation of maintenance treatment at 120 mg/kg/d. Individualize dosing based on renal function. |
| Adult Dose | Induction: 60 mg/kg/dose IV q8h or 100 mg/kg q12h for 14-21 d Maintenance: 90-120 mg/kg/d IV as single infusion for life |
| Pediatric Dose | <12 years: Not established >12 years: Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | Because of its potential for renal impairment, combination with potentially nephrotoxic drugs (eg, aminoglycosides, amphotericin B, pentamidine) should be avoided, unless potential benefits outweigh risks Pentamidine may cause hypocalcemia |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Renal function usually declines—24-h urine creatinine should be determined at baseline and periodically thereafter to ensure correct dosing; discontinue drug if serum creatinine drops to <0.4 mL/min/kg; hydration may reduce nephrotoxicity Because of its propensity to chelate divalent metal ions and alter serum electrolytes, monitor electrolytes (including calcium and magnesium); if patient develops clinical features of electrolyte disturbance (eg, perioral numbness, paresthesias, seizures), determine serum electrolytes immediately Only veins with adequate blood flow (to permit rapid dilution and to avoid local irritation) should be used for administration Granulocytopenia (17%) and anemia (33%) can result from foscarnet, so monitor CBCs regularly Do not administer by rapid or bolus IV injection; resulting excessive plasma levels may increase toxicity |
HIV-1 Associated Progressive Polyradiculopathy excerpt
Article Last Updated: Mar 14, 2007
