Antiviral Agents Flashcards
(37 cards)
ANTIVIRAL AGENTS: action
Action – Work by interfering with viral replication.
DRUGS FOR NON HIV VIRUSES
Acyclovir [Zovirax
Drugs – Acyclovir [Zovirax]*** – used for herpes simplex I & II, varicella-zoster, and herpes zoster. Decreases duration & severity of HSV attacks but does not prevent them.
Routes – PO or IV, topical.
Action – nucleoside analog which mimics one of the substances needed for DNA replication. Virus thus cannot reproduce. SE – local tissue irritation and damage, HA, N/V/D, reversible renal impairment
DRUGS FOR NON HIV VIRUSES
Gancyclovir [Cytovene]* - treat CMV, retinitis.
Valacyclovir [Valtrex]* – herpes etc.
Docosanol –[Abreva] – for cold sores. topical – no systemic absorption – OTC
Cidofovir [Vistide] – CMV retinitis in pts with AIDS
Famciclovir [Famvir] – Genital herpes and shingles
Foscarnet [Foscavir] – IV – CMV & herpes
DRUGS FOR NON HIV VIRUSES; Drug interactions
Drug interactions – several – including cytotoxic agents (e.g. CA drugs)
DRUGS FOR NON HIV VIRUSES; Interventions
Interventions – watch for therapeutic and adverse effects. Advise pt of childbearing age to use contraception during and for at least 3 months after gancyclovir tx because it may cause mutations. Also don’t breast feed while on it.
ANTI-VIRALS FOR FLU
Amantadine [Symmetrel]
Amantadine [Symmetrel]*** – used for influenza A virus in high risk groups. Must be given before attack or within 48 hrs. Can be given with flu shot to protect pt while immunity is developing. (also used for Parkinson’s disease – antidyskinetic).
oseltamivir [Tamiflu]
oseltamivir [Tamiflu]** – also neuraminidase inhibitor.
Comes as a PO form. Also must be taken within 2 days of sx start. Taken BID x 5 days.
SE: N/V
Effect: Reduces time to Sx relief by about 1.3 days
rimantadine [Flumadine]
rimantadine [Flumadine]* – like Symmetrel.
SE: NV, abd pain.
Reverse transcriptase inhibitors
Reverse transcriptase is an enzyme needed by virus for DNA synthesis – not found in human cells. Drug mimics the nucleoside and fools the virus → cannot replicate. One of the classes always used in HAART. These are Prodrugs.
Reverse transcriptase inhibitors: SE
SE: NVD, HA, fatigue during first few weeks.
Reverse transcriptase inhibitors: SE II
Toxic to mitochondria – inhibit gamma-polymerase needed for DNA in mitochondria - can → lactic acidosis & severe hepatomegaly with steatosis syndrome. More common in women and with liver damage to start with. Get increased liver enzymes, fatty liver, maybe failure. SX: N, myalgia, RUQ pain.
Reverse transcriptase inhibitors: SE III
Mitochondrial toxicity also → lipodystrophy. Face, arms, legs lose fat. Fat deposited on abdomen, breasts, and base of neck (buffalo hump).
Zidovudine [AZT, Retrovir]
Drugs – Zidovudine [AZT, Retrovir]*** – For AIDS. Helps control opportunistic infections like PCP. Current dosing is Q12H.
Interactions: Many! Including ASA and Tylenol.
Reverse transcriptase inhibitors: ADVERSS EFFECTS
Adverse effects: N/V/D/A, headache, fever, listlessness, skin rashes. potentially nephrotoxic. Can cause granulocytopenia, and anemia. Also: dizziness, agitation, restlessness, insomnia, n/v/d/a, abdominal pain, dyspepsia, myalgia, diaphoresis, dyspnea, fever, rash, and taste perversion.
Reverse transcriptase inhibitors INTERVENTIONS
Interventions: Take around the clock. Does not reduce risk of passing virus to others. Don’t use OTC drugs without checking with nurse first. Resistance develops in 3-6 mo if used alone.
Reverse transcriptase inhibitors DRUGS
Drugs – abacavir [Ziagen]* emtricitabine [Emtriva]* lamivudine [Epivir]* stavudine [Zerit]* tenofovir [Viread]*
NonNucleoside Reverse Transcriptase inhibitors [NNRTIs]
Action – Inhibit reverse transcriptase by binding close to it and changing its shape.
SE – Rash (can be Steven Johnson but rarely); can affect liver
Drugs – Efavirenz [Sustiva]***
Once daily dosage. High fat meals can → absorption 50% which can → toxicity- take on empty stomach.
NonNucleoside Reverse Transcriptase inhibitors SIDE EFFECTS
SE at beginning – sleep disorders, nightmares, dizziness, decrease ability to concentrate, delusions.These slowly go away in about a month. But about ½ of all pts experience these.
Teratogenic.
NonNucleoside Reverse Transcriptase inhibitors DRUGS
Delavirdine [Rescriptor]*
Nevirapine [Viramune]*
Etravirine [Intelence]*
Protease inhibitors
Action – Work by inhibiting protease. Introduced in 1995 and revolutionized HIV.
SE – GI stuff. Lipodystrophy, increased cholesterol, maybe hyperglycemia and diabetes.
Protease inhibitors KALETRA
Kaletra [lopinavir and ritonavir in combo pill]*** Approved 2000. Ritonavir inhibits the breakdown of lopinavir so much more is available. Much higher blood levels. Take once or twice daily. Drug of choice for first line Tx. Interacts with St. John’s wort → lower antiviral.
Protease inhibitors SAQUINAVIR
Saquinavir [Invirase]* – First of these new drugs approved by FDA - in only 97 days! Should be used as part of combo tx with AZT, etc.
Protease inhibitors
NELFINAVIR
Nelfinavir [Viracept]* – approved 1997.
SE: diarrhea (this is severe and most common problem), nausea, flatulence, rash,
Protease inhibitors
Ritonavir [Norvir]
Ritonavir [Norvir]* – most likely to cause SE and toxicity problems. Used to “boost” blood levels of others – inhibits CYP 450 so others stay at higher levels.
SE: N/V/D/A, HA, fatigue, taste disturbances, circumoral (lip) paresthesia. Diarrhea often severe enough to → noncompliance.
