Clinical Manual for Management of the HIV-Infected ... - myCME.com

INH may cause liver toxicity and its use should be
monitored carefully in patients with active alcohol
use, liver disease, or chronic hepatitis B or C. INH
is contraindicated in patients with acute hepatitis or
decompensated liver disease. Before INH use, baseline
liver and renal function tests should be checked.
Routine monthly clinical monitoring for fever, fatigue,
anorexia, nausea, vomiting, abdominal pain, jaundice,
peripheral neuropathy, and rash should be performed.
Alanine aminotransferase (ALT) should be monitored
monthly in HIV-infected patients and others at risk
for hepatitis. If patients develop abnormalities in liver
transaminases while taking INH (ALT or aspartate
aminotransferase >3 times the upper limit of normal
with symptoms, or >5 times the upper limit of normal
in the absence of symptoms), INH should be withheld.
Obtain expert consultation before treating patients with
abnormal liver function tests or advanced liver disease.
Before rifampin use, baseline liver and renal function
tests and a complete blood count are suggested. Followup
is the same as for INH use.
Drug Interactions with Antiretroviral Therapy
Rifampin and rifabutin have significant interactions
with certain antiretroviral drugs, including
nonnucleoside reverse transcriptase inhibitors
(NNRTIs) and protease inhibitors (PIs). Rifampin
can be used in persons taking efavirenz, although
some experts recommend increasing the efavirenz
dosage to 800 mg daily. Rifampin decreases the
blood concentrations of nevirapine and all unboosted
PIs (except ritonavir) and should not be used with
these drugs. Standard ritonavir boosting of PIs fails
to overcome the drug interaction, causes additional
toxicity, or both. Although recommended in the past,
rifampin should not be used in combination with
ritonavir-boosted saquinavir because of high rates of
hepatic toxicity. Adding more ritonavir to the fixeddose
combination of lopinavir/ritonavir (Kaletra) may
overcome the pharmacokinetic effects of concurrent
rifampin, but the regimen is poorly tolerated. Use of
ritonavir-boosted PI regimens in combination with
rifampin is best avoided and should be done only in
consultation with an expert.
No data are available on the use of rifabutin for the
treatment of LTBI. Nevertheless, rifabutin may be
considered in place of rifampin for patients taking
antiretroviral combinations that include NNRTIs (other
than efavirenz) or PIs (other than ritonavir alone).
Section 2—Health Maintenance and Disease Prevention | 2–41
In these cases, the dosages of both rifabutin and the
antiretroviral agent usually require adjustment.
Table 2 presents information on combining
antiretroviral agents with rifampin or rifabutin.
Other Drug Interactions
Rifampin decreases the blood concentrations of
estrogens, anticonvulsants, hypoglycemic agents, and
many other drugs. Review all medications a patient is
taking before initiating rifampin and make adjustments
as necessary. (See Table 12: Clinically significant drugdrug
interactions involving rifamycins at www.cdc.gov/
mmwr/preview/mmwrhtml/rr5211a1.htm#tab12.)
Pregnancy
HIV-infected pregnant women with a positive TST
and no evidence of active TB should receive standard
prophylaxis as soon as possible, even during the first
trimester. The preferred prophylaxis in pregnancy is a
9-month INH regimen (with pyridoxine, as above).
Alternative regimens, such as rifampin or rifabutin,
should be used with caution because of limited
experience. Neonates born to women who received
rifampin during pregnancy should be given vitamin
K (10 mg) to reduce the risk of hemorrhagic disease.
Pyrazinamide generally is avoided during pregnancy
because of lack of information about fetal effects.