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

Table 1. Interactions between Rifabutin and Antiretroviral
Medications: Contraindicated Combinations and Dosage
Adjustments
Antiretroviral Agent Management When Used with Rifabutin
Nonnucleoside Reverse Transcriptase Inhibitors
Efavirenz Use standard efavirenz dosage; increase
rifabutin to 450-600 mg daily.
Nevirapine Use standard dosage of nevirapine; give
rifabutin at 300 mg daily or 3 times weekly.
Delavirdine Do not combine.
Ritonavir-Boosted Protease Inhibitors
Lopinavir/Ritonavir
(Kaletra)
All Other Ritonavir-
Boosted PIs
Give standard dosage of lopinavir/ritonavir;
decrease rifabutin to 150 mg alternate days or
3 times weekly.
Give standard dosage of PI/ritonavir; decrease
rifabutin to 150 mg on alternate days or 3
times weekly.
Unboosted Protease Inhibitors
Ritonavir Use ritonavir at standard dosage; give
rifabutin at 150 mg on alternate days or 3
times weekly.
Amprenavir,
Fosamprenavir
Use PIs at standard dosages; give rifabutin at
150 mg/day or 300 mg 3 times weekly.
Atazanavir Give atazanavir at standard dosage; give
rifabutin at 150 mg on alternate days or 3
times weekly.
Indinavir Increase indinavir to 1,000 mg every 8 hours;
give rifabutin at 150 mg/day or 300 mg 3
times weekly.
Nelfinavir Increase nelfinavir to 1,000 mg every 8 hours;
give rifabutin at 150 mg/day or 300 mg 3
times weekly.
Ritonavir Give ritonavir at standard dosage; give
rifabutin at 150 mg on alternate days or 3
times weekly.
Source: HIV InSite. Database of Antiretroviral Drug Interactions. San Francisco: UCSF Center for HIV
Information. Available online at http://hivinsite.ucsf.edu/arvdb?page=ar-00-02. Accessed April 26, 2006.
The patient should show clinical improvement within
the first weeks of treatment. If the patient is not
responding to treatment after 2-4 weeks of therapy,
assess adherence, consider adding 1 or more drugs, and
consider evaluation for other or additional causes of the
patient’s symptoms. Consider repeating a blood culture
with antimicrobial sensitivities in patients whose clinical
status has not improved after 4-8 weeks of treatment.
If immune reconstitution inflammatory reactions
are suspected, consider adding anti-inflammatory
medications (see chapter Immune Reconstitution
Syndrome).
Section 6—Disease-Specific Treatment | 6–63
Treatment of MAC is generally required for the
remainder of the patient’s life, although it may be
reasonable to discontinue MAC therapy if patients
complete at least 12 months of MAC treatment,
have no further symptoms, and demonstrate immune
restoration in response to ART (an increase in CD4
counts to >100 cells/µL for at least 6 months). If
MAC treatment is discontinued, the patient must be
monitored carefully for any decrease in CD4 cell count
or recurrence of MAC symptoms. Some clinicians verify
negative AFB cultures before discontinuing therapy.
Treatment should be resumed if the CD4 count drops
to 50-100 cells/µL in response to ART.
Patients must take all medicines exactly as
prescribed. If doses are missed, or if the medication
is stopped and restarted, Mycobacterium can develop
resistance to the medications. If patients are
having trouble taking the medications on schedule,
they should contact their health care providers
immediately.
Educate patients about the benefits of ART in
strengthening the immune system and preventing
opportunistic infections such as DMAC.
Urge patients to contact the clinic immediately if
they notice worsening symptoms, or new symptoms.
DMAC is an opportunistic infection of late-stage
HIV and indicates profound immune suppression.
Some patients may not respond to MAC treatment
or to ART. Because this is a life-threatening disease,
clinicians should discuss advance directives and
durable power of attorney with patients. Referral to
a social worker, mental health clinician, or chaplain
experienced in such issues may facilitate this
discussion.