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Antiviral Medications

Swine (H1N1) Flu Treatment:

CDC recommends the use of oseltamivir or zanamivir for the treatment and/or prevention of infection with swine influenza viruses.

Oseltamivir (Tamiflu ®) 75 mg 1 cap bid PO x 5 days is approved to both treat and prevent influenza A and B virus infection in people one year of age and older.

Zanamivir (Relenza ®) 10 mg daily by oral inhalation 2 puffs bid x 5 days is approved to treat influenza A and B virus infection in people 7 years and older and to prevent influenza A and B virus infection in people 5 years and older.

Clinicians should consider treating any person with confirmed or suspected swine influenza with an antiviral drug. Visit: Interim Guidance on Antiviral Recommendations.

What is novel H1N1 (swine flu)?            REF:  

Novel H1N1 (referred to as “swine flu” early on) is a new influenza virus causing illness in people. This new virus was first detected in people in the United States in April 2009. Other countries, including Mexico and Canada, have reported people sick with this new virus. This virus is spreading from person-to-person, probably in much the same way that regular seasonal influenza viruses spread.

What are the signs and symptoms of this virus in people?

The symptoms of novel H1N1 flu virus in people are similar to the symptoms of seasonal flu and include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. A significant number of people who have been infected with this virus also have reported diarrhea and vomiting. Also, like seasonal flu, severe illnesses and death has occurred as a result of illness associated with this virus.

How long can an infected person spread this virus to others?

At the current time, CDC believes that this virus has the same properties in terms of spread as seasonal flu viruses. With seasonal flu, studies have shown that people may be contagious from one day before they develop symptoms to up to 7 days after they get sick. Children, especially younger children, might potentially be contagious for longer periods.

Can I get infected with novel H1N1 virus from eating or preparing pork?

No. Novel H1N1 viruses are not spread by food. You cannot get infected with novel HIN1 virus from eating pork or pork products. Eating properly handled and cooked pork products is safe.

Prevention & Treatment

What can I do to protect myself from getting sick?

There is no vaccine available right now to protect against novel H1N1 virus. There are everyday actions that can help prevent the spread of germs that cause respiratory illnesses like influenza.

Take these everyday steps to protect your health:

  • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hand cleaners are also effective.
  • Avoid touching your eyes, nose or mouth. Germs spread this way.
  • Try to avoid close contact with sick people.
  • Stay home if you are sick for 7 days after your symptoms begin or until you have been symptom-free for 24 hours, whichever is longer. This is to keep from infecting others and spreading the virus further.

What is the best way to keep from spreading the virus through coughing or sneezing?

If you are sick, limit your contact with other people as much as possible. If you are sick, stay home for 7 days after your symptoms begin or until you have been symptom-free for 24 hours, whichever is longer. Cover your mouth and nose with a tissue when coughing or sneezing. Put your used tissue in the waste basket. Then, clean your hands, and do so every time you cough or sneeze.

For recurrent cold sores:  
Denavir/Penciclovir 1% cream q2h for 4 days.
Aphthasol (Amlexanox oral paste) 5 % dab on affected qid till healed (for oral aphthous ulcers)  
Zovirax/ Acyclovir 5% topical ointment


Prophylaxis Rx for Influenza Virus Infection:  

  1. Injectable IM  Influenza trivalent vaccine shot - killed inactivated virus components
  2. Tamiflu/ Oseltamivir  75 mg cap bid  PO x 5 days for Influenza A & B in adults.
    -  Conclusions: Oseltamivir administered daily for six weeks by the oral route is safe and effective for the prevention of influenza. (N Engl J Med Oct.28,1999;341:1336-43.;  See also  Editorial )
    Adverse effects: nausea & vomiting, headache.

    PLUS  Amantadine/Symmetrel 100 mg cap bid for adult x 5 days  (2009 Influenza Rx Recommendation)
  3. Relenza® (Zanamivir) 10 mg daily by oral inhalation 2 puffs bid x 5 days for Influenza A & B, age >12 yo.
    (JAMA July 7, 1999:282:31 Arnold S. Monto, etc.)
    Adverse effects: nasal & throat discomfort, cough, bronchospasm, headache.
  4. Amantadine/Symmetrel 100 mg cap bid for adult x 10-14 days
    Adverse effects: may cause nausea, dizziness, insomnia, depression, anxiety, irritability, hallucinations, seizures, anorexia, dry mouth, etc.
  5. Rimantadine/Flumadine 100 mg tab bid for adult x 7-10 days 
    Adverse effects: similar to amantadine but with less frequency & severity.
  6. Intranaal Influenza mist (FluMist) - live attenuated viruses.
    Contraindicated in patiens with egg allergy, immunocompromised persons, persons at high risk for complications of influenza infection (age >65, COPD, asthma, cystic fibrosis)


Rx of Herpes Zoster (Shingles):
  • Famvir/Famciclovir  500 mg tid x1week for Shingles
  • Zovirax/Acyclovir  800 mg 5x/day x 7-10 days for Shingles
  • Valtrex/Valacyclovir  500 mg 2 caplets tid x1 week for Shingles.
  • IV acyclovir  5-10 mg/kg IV q 8 h for 7-10 days  or
  • IV foscarnet for 14 days (until healing) for disseminated Herpes Zostrer disease.
    Recent Advances in Varicella-Zoster Virus Infection.  (AIM  June 1, 1999;130: 922  - Jeffrey Cohen, etc)


Rx of Genital Herpes
  • Zovirax/Acyclovir  200 mg 5x/day x 10days for first episode, x 5 days for recurrent episodes.
  • Famvir/Famciclovir   250 mg tid x 7-10 days for first episode; 500 mg bid for chronic suppression of genital herpes in HIV+ patients.

Suppression Rx of Recurrent Genital Herpes Simplex:

  • Zovirax/Acyclovir 400 mg bid
  • Famvir/Famciclovir  125 mg bid x 5 days for recurrence; 250 mg bid for chronic suppression Rx.  
  • Once-daily suppressive therapy with  500 mg of Valtrex/Valacyclovir once daily for 8 months significantly reduces the risk of transmission of genital herpes among heterosexual, HSV-2–discordant couples.   Episodic therapy with valacyclovir (500 mg twice a day) for five days was offered for recurrences.
    NEJM 1/1/2004, Volume 350:11-20   Lawrence Corey, M.D., etc.


For CMV retinitis: Vistide/Cidofovor IV


External Genital Warts Rx:

Condylox (Podofilox) 0.5% solution or gel bid x 3 days, then no Rx for 4 days (cycle may be repeated for a total of 4 cycles)

Aldara (Imiquimod) 5 % cream 3x/wk at night, continue until totally clear or up to 16 wks.
  (Wash Rx area with soap & water 6-10 hours after application)


Post-exposure to HIV Prophylaxis 9-1996:
Zidovudine/AZT 200 mg tid or 300 mg bid + Lamivudine/3TC 150 mg bid  x 4 weeks   or
Stavudine 400 mg bid + Didanosine 125-200 mg bid x 4 weeks;
Consider add 3 rd drug as Indinavir 800 mg tid or Nelfinavir 750 mg tid (in high load exposure)
Start Rx within 72 hours of exposure.
Test HIV antibody at baseline, 3 - 6 -12 months
Test HIV viral load count, Hepatitis B & C antibodies ,VDRL, Gonorrhea, Chlamydia, LFT, Creat, CBC, (pregnancy if indicated) screen


Nucleoside analog (RTI):
AZT/ZVD=Zidovudine/Retrovir 200 mg tid
3TC/Epivir/Lamivudine 150 mg bid
ddC/Hivid/Zalcitabine 0.75 mg tid
ddI/Videx/Didanosine 200 mg bid
d4T/Zerit/Stavudine 15-20-30-40 mg cap bid

Protease Inhibitor:
Crixivan/Indinavir=IDV  800 mg tid
Viracept/Nelfinavir 250 mg 3 tab tid
Norvir/Ritonavir=RTV  600 mg cap bid
Invirase/Saquinavir=SQV/Fortovase 600 mg tid

Non-Nucleoside Analogues (NNRTI):
Viramune/Nevirapine=NVP  200 mg bid

Combination Rx, as:
AZT+3TC, d4T+ddI, ddI+Hydrozyurea,


Management of Exposures to HIV                                                            REF:  MMWR June 29, 2001 / 50(RR11);1-42

Clinical Evaluation and Baseline Testing of Exposed HCP (Health Care Personnel)

HCP exposed to HIV should be evaluated within hours (rather than days) after their exposure and should be tested for HIV at baseline (i.e., to establish infection status at the time of exposure). If the source person is seronegative for HIV, baseline testing or further follow-up of the exposed person normally is not necessary. Serologic testing should be made available to all HCP who are concerned that they might have been occupationally infected with HIV. For purposes of considering HIV PEP (Post-Exposure Prophylaxis), the evaluation also should include information about medications the exposed person might be taking and any current or underlying medical conditions or circumstances (i.e., pregnancy, breast feeding, or renal or hepatic disease) that might influence drug selection.

PEP (Post-Exposure Prophylaxis) for HIV

The following recommendations (Table 4 and Table 5) apply to situations when a person has been exposed to a source person with HIV infection or when information suggests the likelihood that the source person is HIV-infected. These recommendations are based on the risk for HIV infection after different types of exposure and on limited data regarding efficacy and toxicity of PEP. Because most occupational HIV exposures do not result in the transmission of HIV, potential toxicity must be carefully considered when prescribing PEP. To assist with the initial management of an HIV exposure, health-care facilities should have drugs for an initial PEP regimen selected and available for use. When possible, these recommendations should be implemented in consultation with persons who have expertise in antiretroviral therapy and HIV transmission .

Timing and Duration of PEP. PEP should be initiated as soon as possible.
Although animal studies suggest that PEP probably is substantially less effective when started more than 24--36 hours postexposure, the interval after which no benefit is gained from PEP for humans is undefined. Therefore, if appropriate for the exposure, PEP should be started even when the interval since exposure exceeds 36 hours. Initiating therapy after a longer interval (e.g., 1 week) might be considered for exposures that represent an increased risk for transmission. The optimal duration of PEP is unknown. Because 4 weeks of ZDV appeared protective in occupational and animal studies (100,123), PEP probably should be administered for 4 weeks, if tolerated.

Use of PEP When HIV Infection Status of Source Person is Unknown.
If the source person's HIV infection status is unknown at the time of exposure, use of PEP should be decided on a case-by-case basis, after considering the type of exposure and the clinical and/or epidemiologic likelihood of HIV infection in the source (Table 4 and Table 5). If these considerations suggest a possibility for HIV transmission and HIV testing of the source person is pending, initiating a two-drug PEP regimen until laboratory results have been obtained and later modifying or discontinuing the regimen accordingly is reasonable.

The following are recommendations regarding HIV postexposure prophylaxis:

  • If indicated, start PEP as soon as possible after an exposure.
  • Reevaluation of the exposed person should be considered within 72 hours postexposure, especially as additional information about the exposure or source person becomes available.
  • Administer PEP for 4 weeks, if tolerated.
  • If a source person is determined to be HIV-negative, PEP should be discontinued.

PEP for Pregnant HCP.
If the exposed person is pregnant, the evaluation of risk of infection and need for PEP should be approached as with any other person who has had an HIV exposure. However, the decision to use any antiretroviral drug during pregnancy should involve discussion between the woman and her health-care provider(s) regarding the potential benefits and risks to her and her fetus.

Certain drugs should be avoided in pregnant women.
Because teratogenic effects were observed in primate studies, EFV is not recommended during pregnancy. Reports of fatal lactic acidosis in pregnant women treated with a combination of d4T and ddI have prompted warnings about these drugs during pregnancy. Because of the risk of hyperbilirubinemia in newborns, IDV should not be administered to pregnant women shortly before delivery.

Recommendations for the Selection of Drugs for HIV PEP

Health-care providers must strive to balance the risk for infection against the potential toxicity of the agent(s) used when selecting a drug regimen for HIV PEP. Because PEP is potentially toxic, its use is not justified for exposures that pose a negligible risk for transmission (Table 4 and Table 5). Also, insufficient evidence exists to support recommending a three-drug regimen for all HIV exposures. Therefore, two regimens for PEP are provided (Appendix C): a "basic" two-drug regimen that should be appropriate for most HIV exposures and an "expanded" three-drug regimen that should be used for exposures that pose an increased risk for transmission (Table 4 and Table 5). When possible, the regimens should be implemented in consultation with persons who have expertise in antiretroviral treatment and HIV transmission.

Most HIV exposures will warrant a two-drug regimen using two nucleoside analogues (e.g., ZDV and 3TC; or 3TC and d4T; or d4T and ddI). The addition of a third drug should be considered for exposures that pose an increased risk for transmission. Selection of the PEP regimen should consider the comparative risk represented by the exposure and information about the exposure source, including history of and response to antiretroviral therapy based on clinical response, CD4+ T-cell counts, viral load measurements, and current disease stage. When the source person's virus is known or suspected to be resistant to one or more of the drugs considered for the PEP regimen, the selection of drugs to which the source person's virus is unlikely to be resistant is recommended; expert consultation is advised. If this information is not immediately available, initiation of PEP, if indicated, should not be delayed; changes in the PEP regimen can be made after PEP has been started, as appropriate. Reevaluation of the exposed person should be considered within 72 hours postexposure, especially as additional information about the exposure or source person becomes available.

Follow-up of HCP Exposed to HIV

Postexposure Testing. HCP with occupational exposure to HIV should receive follow-up counseling, postexposure testing, and medical evaluation, regardless of whether they receive PEP. HIV-antibody testing should be performed for at least 6 months postexposure (e.g., at 6 weeks, 12 weeks, and 6 months). Extended HIV follow-up (e.g., for 12 months) is recommended for HCP who become infected with HCV following exposure to a source coinfected with HIV and HCV. Whether extended follow-up is indicated in other circumstances (e.g., exposure to a source coinfected with HIV and HCV in the absence of HCV seroconversion or for exposed persons with a medical history suggesting an impaired ability to develop an antibody response to acute infection) is unclear. Although rare instances of delayed HIV seroconversion have been reported (167,168), the infrequency of this occurrence does not warrant adding to the anxiety level of the exposed persons by routinely extending the duration of postexposure follow-up. However, this recommendation should not preclude a decision to extend follow-up in an individual situation based on the clinical judgement of the exposed person's health-care provider. HIV testing should be performed on any exposed person who has an illness that is compatible with an acute retroviral syndrome, regardless of the interval since exposure. When HIV infection is identified, the person should be referred to a specialist knowledgeable in the area of HIV treatment and counseling for medical management.

HIV-antibody testing with EIA should be used to monitor for seroconversion. The routine use of direct virus assays (e.g., HIV p24 antigen EIA or tests for HIV RNA) to detect infection in exposed HCP generally is not recommended (169). The high rate of false-positive results of these tests in this setting could lead to unnecessary anxiety and/or treatment (170,171). Despite the ability of direct virus assays to detect HIV infection a few days earlier than EIA, the infrequency of occupational seroconversion and increased costs of these tests do not warrant their routine use in this setting.

  • HIV-antibody testing should be performed for at least 6 months postexposure.
  • Direct virus assays for routine follow-up of HCP are not recommended.
  • HIV testing should be performed on any exposed person who has an illness compatible with an acute retroviral syndrome.