INFECTIONS & INFESTATIONS
Viral infections 11D
prolonged nucleoside exposure: increased risk of
toxicity. Cardiovascular disease. Diabetes. Smoking.
Bone marrow depression. Anemia. Myopathy. Not
for treating hepatitis B; monitor patients co-infected
with HBV for at least several months after stopping
treatment (discontinuing therapy may exacerbate
HBV infection). If stopped for reasons other than
hypersensitivity, restart only if medical care can be
readily accessed; monitor for hypersensitivity. Monitor
blood counts. Elderly. Pregnancy (Cat.C). Nursing
mothers: not recommended.
Interactions: Avoid zalcitabine, stavudine,
doxorubicin, ribavirin, emtricitabine, tenofovir, other
forms of abacavir, lamivudine, or zidovudine. Abacavir
may antagonize methadone. TMP/SMX, nelfinavir
may increase lamivudine levels. Ethanol may
increase abacavir levels. Atovaquone, fluconazole,
methadone, nelfinavir, probenecid, ritonavir, valproic
acid may affect zidovudine levels; monitor. Increased
hematologic toxicity with ganciclovir, other bone
marrow suppressants or cytotoxic agents. Triple
therapy (once daily regimen) with tenofovir or with
didanosine ; tenofovir: high rate of early viral
non-response (see literature). Monitor for treatment-associated toxicities with interferon-alpha with or
without ribavirin.
Adverse reactions: GI upset, anorexia, insomnia,
lab abnormalities (anemia, neutropenia, elevated
liver enzymes and CPK, mild hyperglycemia, elevated
triglycerides), headache, malaise, myopathy, myositis,
neuropathy, lactic acidosis, severe hepatomegaly
with steatosis, hypersensitivity reactions (may
be fatal), nasal symptoms, cough, fever/chills,
depression, fat redistribution, rash (may be severe,
eg, Stevens-Johnson), dizziness, myalgia, arthralgia,
post-treatment exacerbation of hepatitis, immune
reconstitution syndrome.
Note: Register pregnant patients exposed to Trizivir
by calling (800) 258-4263. Register patients who
have had a hypersensitivity reaction to abacavir by
calling (800) 270-0425.
How supplied: Tabs– 60
;ACYCLOVIR
ACYCLOVIR INJECTION (various)
Nucleoside analogue. Acyclovir (as sodium)
500mg/vial; lyophilized pwd for IV infusion after
reconstitution and dilution; contains sodium
49mg/vial.
Indications: Genital herpes (severe initial episodes
in immunocompetent patients). Herpes simplex (in
neonates, and as initial and recurrent treatment
in immunocompromised patients). Herpes simplex
encephalitis. Varicella zoster (immunocompromised
patients).
Adults: Give by IV infusion over 1 hour.
Mucocutaneous herpes simplex (immunocompromised):
5mg/kg every 8 hours for 7 days. Genital herpes:
5mg/kg every 8 hours for 5 days. Encephalitis:
10mg/kg every 8 hours for 10 days. Varicella zoster
(immunocompromised): 10mg/kg every 8 hours for
7 days. All: max 20mg/kg every 8 hours. Obese:
dose based on ideal body weight. Renal impairment:
CrCl 25–50mL/min: give dose every 12 hours;
CrCl 10–25mL/min: give dose every 24 hours;
CrCl;10mL/min: reduce dose by 50% and give every
24 hours. Coincide a dose for after hemodialysis.
Children: Give by IV infusion over 1 hour. Neonatal
(birth–3mos) herpes simplex: 10mg/kg every 8 hours
for 10 days (doses of 15–20mg/kg every 8 hours
have been used; see literature). Mucocutaneous
herpes simplex (immunocompromised): 10mg/kg
every 8 hours for 7 days. Encephalitis: 3mos–12yrs:
20mg/kg every 8 hours for 10 days. Varicella zoster:
;12yrs (immunocompromised): 20mg/kg every 8
hours for 7 days. All: max 20mg/kg every 8 hours.
Obese: dose based on ideal body weight. Renal
impairment: CrCl 25–50mL/min: give dose every
12 hours; CrCl 10–25mL/min: give dose every 24
hours; CrCl ;10mL/min: reduce dose by 50% and
give dose every 24 hours. Coincide a dose for after
hemodialysis.
Contraindications: Valacyclovir hypersensitivity.
Warnings/Precautions: Renal impairment: see
literature. Maintain adequate hydration. Neurological
or serious renal, hepatic, or electrolyte abnormalities,
or significant hypoxia. Elderly. Pregnancy (Cat.B).
Nursing mothers.
Interactions: Avoid nephrotoxic drugs. Potentiated
by probenecid.
Adverse reactions: Inj site reactions, transient
elevated BUN and serum creatinine, GI upset,
pruritus, rash, CNS effects (esp. in elderly), elevated
transaminases, hematologic abnormalities, renal
failure, thrombotic thrombocytopenic purpura/
hemolytic uremic syndrome in immunocompromised
patients.
How supplied: Contact supplier.
;ATAZANAVIR
REYATAZ Bristol-Myers Squibb
HIV- 1 protease inhibitor. Atazanavir (as sulfate)
100mg, 150mg, 200mg, 300mg; caps.
Indications: HIV- 1 infection.
Adults: Take with food. Therapy-naive: atazanavir
300mg ; ritonavir 100mg, both once daily; or
atazanavir 400mg once daily if unable to tolerate
ritonavir. Therapy-experienced: atazanavir 300mg
; ritonavir 100mg; both once daily. Concomitant
efavirenz (must also give ritonavir; not for therapy-experienced): atazanavir 400mg ; ritonavir 100mg
(both as a single daily dose) ; efavirenz 600mg
(on an empty stomach at bedtime). Concomitant
tenofovir (must also give ritonavir): consider giving
atazanavir 300mg ; tenofovir 300mg ; ritonavir
100mg; all as a single daily dose; see literature.
Concomitant H2 blockers or PPIs: see literature. ESRD
with hemodialysis: therapy-naive: atazanavir 300mg
; ritonavir 100mg. Moderate hepatic impairment:
300mg once daily. Pregnancy (2nd or 3rd trimester):
treatment-experienced plus concomitant H2-blocker
or tenofovir: atazanvir 400mg ; ritonavir 100mg,
