Antivirals and Disinfectants Flashcards

Question

3 Topical Agents

Answer 1

• Penciclovir (Denavir) – 1% cream, for oral herpes lesions – Apply every 2 hours while awake for 4 days – Headache, local skin reactions • Docosanol (Abreva) – 10% cream, available OTC, for oral herpes lesions – Rub in a thin layer gently but completely 5 times daily until healed • May apply cosmetics over this product • Trifluridine (Viroptic) – 1% ophthalmic solution, for primary keratoconjunctivitis and recurrent epithelial keratitis caused by HSV – Dose de-escalation procedure

Answer 2

– DNA virus – Typically result from reactivation in immunocompromised patients • HIV, transplant – Dissemination results in end-organ disease • Retinitis, colitis, esophagitis, CNS disease, pneumonitis • Treatments are virustatic – Arrest DNA synthesis by inhibiting viral DNA polymerase • Completely different regimens than used for HSV or VZV – Increased toxicity

Answer 3

replaced with valganciclovir – Converted to ganciclovir triphosphate • Incorporated into viral DNA • Inhibits viral DNA polymerase • Terminates viral replication – Does exhibit activity against HSV, VZV, EBV • Too toxic to be used for those viruses

Answer 4

• Adverse effects – Black box warning: bone marrow toxicity • Special considerations – Hydrate aggressively – Monitor renal function and adjust accordingly – Avoid direct contact with skin • Extremely alkaline solution, teratogenic and carcinogenic

Answer 5

DRUG OF CHOICE for Tx and Px! (oral) • Special considerations – PO only – Look-alike/sound-alike names • Valganciclovir and valacyclovir

Answer 6

Mechanism of action – Binds noncompetitively to viral DNA polymerase to form an inactive complex and prevents pyrophosphate cleavage • Results in termination of viral DNA chain elongation – Broad spectrum of activity • Covers HSV, VZV – Reserved for acyclovir-resistant strains • Covers CMV, influenza, HIV – Not used for the latter 2 – Used as second-line to valganciclovir for CMV

Answer 7

* Agents utilized – PO * Adefovir, lamivudine, entecavir, telbivudine, tenofovir – Subcutaneous * Interferon alfa

Answer 8

1st line treatment • Special considerations – Maintains activity against lamivudine- and entecavir-resistant isolates – Reduced activity against adefovir-resistant isolates – Significantly higher rate of response than adefovir • Less likely to develop resistance • Fewer adverse effects

Answer 9

1st line treatment • Mechanism of action – Carbocyclic analog of guanosine – Phosphorylated to its active form • Then inhibits viral polymerase and halts HBV DNA synthesis – Effective for lamivudine-resistant HBV Adverse effects – Black box warning: severe acute exacerbations of hepatitis upon discontinuation – Dizziness, fatigue, headache, nausea

Answer 10

``` Special considerations for HBV – Dosing is 100 mg PO daily • Epivir HBV dosage form – Very rapid and potent HBV suppression • HOWEVER, resistance is quite common ```

Answer 11

Goals of therapy – Eradicate the virus – Achieve sustained virologic response (SVR) • Undetectable viral load for 6 months after completion of therapy – Improve liver histology – Reduce risk of hepatocellular carcinoma

Answer 12

``` Products available – Pegasys – Peg-Intron • Adverse effects Interferons for HCV Infection – Flu-like syndrome • Headache, myalgias, arthralgias, fatigue. malaise, fever, chills • Improves as treatment continues • Special considerations – Contraindications to therapy • Hepatic decompensation • Autoimmune disease • History of arrhythmia • Pregnancy ```

Answer 13

• Adverse effects – Hemolytic anemia (must monitor CBC q4 weeks) – GI upset – Depression – Teratogenic!! • Special considerations – Handling capsules, pregnancy precautions

Answer 14

``` • Special considerations – $1000 per tablet!! – Pan-genotypic activity – Makes it possible to treat some patients without interferon! Polymerase inhibitor ```

Answer 15

``` • Dosing – 150 mg PO daily with food • Adverse effects – Rash – Itching – Nausea • Special considerations – Assessment of Q80K mutation – Drug interactions!! ```

Answer 16

``` Single stranded RNA virus • Influenza A and Influenza B • Influenza A – Two surface antigens: – hemagglutinin (H1 to H16) and neuraminidase (N1 to N9) ```

Answer 17

Viral Pneumonia Complications of Influenza • Secondary bacterial pneumonia, sinusitis, otitis • Exacerbates other medical conditions – Especially cardiac/pulmonary disease • Also uncommonly associated with: – encephalopathy, transverse myelitis – myositis, myocarditis, pericarditis – Reye’s syndrome

Answer 18

Treat if high risk group within 48 hrs children younger than 2 years old adults 65 years and older pregnant women and women up to 2 weeks postpartum persons with certain chronic medical or immunosuppressive conditions

Answer 19

Chemoprophylaxis if – persons at higher risk for influenza-related complications have significant contact with flu. – Early treatment is alternative to chemoprophylaxis after a suspected exposure. • If clinical signs or symptoms develop, then treat • Best method of routine prevention: inactivated influenza vaccine!!

Answer 20

• Adverse effects – Dry mouth, nausea, anorexia – CNS toxicity (increased risk in elderly) Mechanism of action – Inhibits viral replication by interfering with viral attachment and uncoating • Special considerations – No longer recommended for influenza prophylaxis – Role in treatment in 2012 – Teratogenic – Used to treat Parkinson Disease and drug-induced EPS

Answer 21

• Adverse effects – As with amantadine • Less CNS adverse effects MOA is same as amantadine

Answer 22

• Mechanism of action – Neuraminidase inhibitor – Active against both influenza A and B • Adverse effects – Nausea, vomiting, abdominal pain – CNS adverse effects – Approved for use in ages 1 and over – Dose adjust for renal insufficiency

Answer 23

• Adverse effects – Cough, bronchospasm – Reversible decrease in pulmonary function – Transient nasal and throat discomfort • Special considerations – Avoid use in patients with asthma and COPD – Puncture Rotadisk only when ready to use – FDA alert 10/9/2009!

Answer 24

– Chemicals that inhibit or kill microorganisms (not spores) • Used on inanimate surfaces – Regulated by EPA Disinfectants and Antiseptics can become contaminated with spores and bacteria

Answer 25

– Disinfecting agents that can be applied to skin, mucus membranes, wounds due to low toxicity to host cells • To prevent infection – Regulated by FDA

Answer 26

– Kill both cells and spores when applied for certain duration of time/temperature – Regulated by EPA