Indications
HIV infection (with other antiretrovirals), specifically in patients with only CCR5–tropic HIV-1 detectable, with evidence of viral replication and HIV-1 strains displaying multiple resistance to other antiretrovirals.
Use should be determined by treatment history and tropism testing.
Action
Blocks a specific receptor on CD-4 and T-cell surfaces which prevents CCR5–tropic HIV-1 from entering.
Therapeutic Effects:
Decreased invasion of CD-4 and T-cells by CCR5–tropic HIV-1 virus resulting in viral replication.
Pharmacokinetics Absorption: 2–33% absorbed following oral administration.
Distribution: Unknown.
Metabolism and Excretion: Mostly metabolized by the liver (CYP3A enzyme system); 8% renal excretion as unchanged drug.
Half-life: 14–18 hr.
TIME/ACTION PROFILE (blood levels)
ROUTE
ONSET
PEAK
DURATION
PO
unknown
0.5–4 hr
1–2 hr
Contraindications/Precautions Contraindicated in:
Dual/mixed or CXCR4–tropic HIV-1;
OB: Lactation (breast-feeding not recommended for HIV-infected patients). Use Cautiously in:
Pre-existing liver disease including Hepatitis B or C (may ↑ risk of hepatotoxicity;
Cardiovascular disease or risk factors (increased risk of cardiovascular events;
Hepatic impairment;
Renal impairment (if CCr <50 ml/min and using a CYP3A inhibitor use only if necessary);
Treatment-naive adults (safety/efficacy not established);
Geri: Consider age-related decrease in renal/hepatic function, concurrent drug therapy and concomittant disease;
OB: Use only if clearly needed;
Pedi: Safe use in children <16 yr not established.
Adverse Reactions/Side Effects*
*CAPITALS indicate life threatening; underlines indicate most frequent.
Interactions Drug–Drug:
Levels are ↑ by CYP3A inhibitors including protease inhibitors (excluding tipranavir/ritonavir), delavirdine, ketoconazole, lopinavir/ritonavir, saquinavir, and atazanavir.
Levels are ↓ by CYP3A inducers including efavirenz and rifampin.
Route/Dosage PO (Adults):Concurrent CYP3A inhibitors (except tipranavir/ritonavir) or delavirdine— 150 mg twice daily; Concurrent NRTIs , tipranavir/ritonavir, nevirapine and other drugs that are not strong inhibitors/inducers of CYP3A— 300 mg twice daily; Concurrent CYP3A inducers including efavirenz— 600 mg twice daily.
Availability Tablets: 150mg, 300 mg.
NURSING IMPLICATIONS
Assessment
Assess patient for change in severity of HIV symptoms and for symptoms of opportunistic infections throughout therapy.
Assess for signs of hepatitis or allergic reaction (pruritic rash, jaundice, dark urine, vomiting, abdominal pain). If symptoms occur, discontinue maraviroc immediately.
Lab Test Considerations:
Testing for CCR5–tropic HIV-1 should be obtained prior to initiating therapy
Monitor viral load and CD4 cell count regularly during therapy.
May cause ↑ AST, ALT, total bilirubin, amylase, and lipase.
May cause ↓ absolute neutrophil count.
Potential Nursing Diagnoses Risk for infection (Indications). Deficient knowledge, related to medication regimen (Patient/Family Teaching).
Implementation
PO: May be administered without regard to food. Tablets should be swallowed whole; do not crush, break, or chew.
Patient/Family Teaching
Emphasize the importance of taking maraviroc as directed, at the same time each day. Advise patient to read the Patient Information that come with the medication each time the Rx is refilled. Maraviroc must always be used in combination with other antiretroviral drugs. Do not take more than prescribed amount and do not stop taking without consulting health care professional. If a dose is missed, take as soon as remembered, then return to regular dose schedule. If it is within 6 hr of next dose, omit dose and take next dose at regular time. Do not double doses.
Instruct patient that maraviroc should not be shared with others.
Inform patient that maraviroc does not cure AIDS or prevent associated or opportunistic infections. Maraviroc does not reduce the risk of transmission of HIV to others through sexual contact or blood contamination. Caution patient to use a condom and to avoid sharing needles or donating blood to prevent spreading the AIDS virus to others. The long-term effects of maraviroc are unknown at this time. If new symptoms of infection develop after starting maraviroc, notify health care professional.
Advise patient to discontinue maraviroc and notify health care professional of itchy rash, yellow colored skin or eyes, dark urine, vomiting, or abdominal pain occur.
May cause dizziness. Caution patient to avoid driving and other activities requiring alertness until response to medication is known.
Advise patient to make position changes slowly to minimize postural hypotension.
Instruct patient to consult health care professional before taking any Rx, OTC, or herbal products, especially St. John's Wort; may decrease effectiveness of maraviroc.
Advise patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
Emphasize the importance of regular follow-up exams and blood counts to determine progress and monitor for side effects.
Evaluation/Desired Outcomes
Delayed progression of AIDS and decreased opportunistic infections in patients with HIV.
Decrease in viral load and increase in CD4 cell counts.