HSV pharmacology Flashcards
HSV-1 presentation
Blisters or ulcers around or in the mouth
Transferred via oral secretions
First episode can experience fever, body aches, sore throat, headache, swollen lymph nodes
Recurrence can start with tingling or burning sensation where the sore will form
Establishes in sensory ganglia
Swab or PCR testing
HSV-2 presentation
Bumps, blisters, or ulcers around genitals or anus
Transferred via infected secretions
Recurrence can start with a tingling or burning sensation where the sore will form or can feel pain down leg or buttock
Recurrence are often shorter and less severe than initial outbreak
Establishes in sacral ganglia
Swab or PCR testing
HSV1/2 encephalitis
Mostly caused by HSV-1 (90% of cases) but can be caused by HSV-2
Diagnosis via lumbar puncture and PCR testing
Symptoms: fever, confusion, abnormal behavior, headache, seizures, focal neurological deficits
Acyclovir regimen for HSV-2
Primary: 400 mg PO TID x 7-10 days or 200 mg PO x4h (5x a day) x 7-10 days
Recurrent: 800 mg TID for 2 days or 800 mg PO BID for 5 days
Suppression: 400 mg BID
Acyclovir regimen for HSV-1
400 mg PO TID for 5-10 days
Suppression is the same
Acyclovir regimen for HSV encephalitis
10 mg/kg IV q8h for 14-21 days (adj BW)
Valacyclovir regimen for HSV-1
2g q12h for x 1 day (begin at earliest symptom onset)
Valacyclovir for HSV-2
Primary: 1g po BID x 7-10 days
Recurrent: 500mg po BID x 3 days, 1g po daily x 5 days
Suppression: 500mg – 1000mg po daily in immunocompetent patients
(1g if >10 outbreaks/year)
500mg po BID in HIV-infected patients
Famciclovir SE
Well tolerated
HA, N/V/D, Acute renal failure if not properly dose adjusted
Famciclovir regimen for HSV-1
1.5g single dose (at symptom onset)
Famciclovir regimen for HSV-2
Primary: 250mg po TID x 7-10 days
Recurrent infection:125mg po BID x 5 days, 1g po BID x 1 day, 500mg po x 1, then 250mg po BID x 2 days
Suppression: 250mg po BID
Acyclovir regimen for chickenpox
800mg PO q 4hrs (5x a day) for 5-7 days
Acyclovir regimen for shingles
800mg po q 4hrs (5x a day) for 7-10 days
Acyclovir regimen for sever disseminated disease or VZV encephalitis
10mg/kg IV q8hr for 14-21 days (adjusted body weight)
Valacyclovir regimen for chickenpox
1g po q8hr for 5-7days and until lesions have crusted
Ideally within 24 hours of symptom onset
Valacyclovir regimen for shingles
1g po q8hr for 7days
Start within 48-72hrs of rash onset
Preferred over PO acyclovir
Valacyclovir regimen for disseminated zoster
Initial treatment with IV acyclovir
Treat for 10-14 days
Can transition to valacyclovir once improved
Famciclovir regimen for shingles
500mg po TID for 7 days
Begin within 72 hours of rash onset
Ganciclovir regimen for CMV retinitis
Induction: 5mg/kg IV q12hr for 14-21 days
Maintenance (life long): 5mg/kg IV q24hr, 6mg/kg IV daily for 5 days every week, 100mg PO TID with food
May need intravitreal implants or injections
Ganciclovir regimen for CMV esophagitis, colitis, pneumonitis, neurologic disease
Ganciclovir 5 mg/kg IV q12hr for 14-21 days
Ganciclovir for prevention and treatment of CMV in bone marrow and organ transplant recipients
5 mg/kg IV q12hr for 7-14 days, then 5 mg/kg once daily (7 days/week) or 6 mg/kg once daily (6 days/week)
Valganciclovir regimen for CMV retinitis
Induction: 900mg PO BID for 21 days
Maintenance: 900mg PO daily
Prevention of CMV disease in transplant patients at high risk (based on seropositivity of donor and recipient)
900mg po daily
Start within 10 days of transplant, continue to 100-200
days post transplant (organ dependent)
Letermovir for prophylaxis in CMV and in CMV HSCT
480 mg IV or PO once daily; start between day 0 and day 28 post-
transplantation and continue through day 100 post-transplantation
Dosage should be adjusted to 240 mg IV or PO daily if administered
with cyclosporine (increases concentration)
Letermovir drug interactions
CYP3A4 inhibitor and OATP 1B1/3 transporters
Foscarnet regimen for CMV retinitis
Induction: 60 mg/kg IV q8h or 90 mg/kg q12h for 14-21 days
Maintenance: 90-120 mg/kg IV q24h
Infusion rate not to exceed 1 mg/kg/minute
Combination therapy with ganciclovir is indicated for patients who
relapse with monotherapy with either drug
Foscarnet HSV and VZV (resistant)
40 mg/kg IV q8hr for 14-21 days
Zanamivir
Dry powder inhaler via proprietary diskhaler device
Breath-activated-requires cooperative, trained patient with adequate lung function
Oseltamivir
Ethyl ester prodrug of oseltamivir carboxylate
30 mg, 45 mg, 75 mg capsules
Powder for oral suspension
Peramivir
First parenterally available neuraminidase inhibitor
Potent inhibitor of both Flu A and B; structurally different than oseltamivir and zanamivir less cross resistance
90% eliminated renally as unchanged drug
SE: diarrhea, hypersensitivity reactions
Avoid live flu vaccine within 2 weeks before or 48 hours after
Peramivir dosing
> or equal to 18 years of age who have been symptomatic NO MORE than 2 days
600 mg IV infusion over > 15 minutes, SINGLE DOSE
Adjust dose for renal dysfunction: CrCl 30-49 ml/min–200 mg x1, CrCl 10-29 ml/min–100 mg x 1
Baloxavir Marboxil
MOA: inhibits polymerase acidic endonuclease specific enzyme in the viral DNA polymerase complex required for viral gene transcription
Prodrug
Avoid dairy products: ZICAM
Diarrhea, nausea, HA
Baloxavir Marboxil regimen
Acute uncomplicated influenza in patients > or equal to 12 years of age who have been symptomatic for no more than 2 days
40 kg to < 80 kg: 40 mg PO single dose
> or equal to 80 kg: 80 mg PO single dose
