Standard DoseThe recommended dose varies depending on other medications being taken but will be either 150, 300, or 600 mg twice daily (available in 150 mg and 300 mg tablets). Approved for adults and children at least two years old weighing at least 22 pounds (10 kg) and having a creatinine clearance of at least 30mL/min (measurement of kidney function); dose depends on weight. Available in a 20 mg/mL oral solution as well as 25 mg and 75 mg tablets. The oral solution should be administered using the included press-in bottle adapter and oral dosing syringe. Can be taken without regard to food. Must be taken in combination with another antiretroviral(s).
Take the missed dose as soon as possible, unless it is closer in time to your next dose. Do not double up on your next dose. Before you start Selzentry, you will need a specific blood test called a Trofile to determine if this medication will work for you.
See package insert for more complete information on potential side effects and interactions.
AWP300 mg tablets, 60 tablets: $1,874.44/month
Potential Side Effects and Toxicity
The most common side effects occurring in greater than 8% of studied patients include cough, pyrexia (fever), upper respiratory tract infections, rash, musculoskeletal symptoms, abdominal pain, and dizziness. Other less common side effects may include allergic reactions, liver toxicity, and heart problems in those with a history of heart disease. Rarely, Selzentry can cause dizziness or fainting when standing up due to low blood pressure. Caution should be used when administering Selzentry in people with a history of or risk factors for postural hypotension, cardiovascular co-morbidities, or on concomitant medication known to lower blood pressure. Stop taking Selzentry and contact your provider right away if you develop a rash, yellowing of your eyes or skin, dark urine, vomiting, or upper stomach pain. Selzentry should not be used by people with severe or end-stage kidney disease who are taking medications that can affect the levels of Selzentry (check with your provider). Selzentry affects immune system cells and could possibly increase the risk of infections and cancer, although this has not been observed in studies up to five years of follow-up, and some data indicate it may be beneficial in cancer or for preventing metastasis (the spread of cancer to other parts of the body).
Potential Drug Interactions
Dose adjustments with other medications and anti-HIV drugs include: 150 mg twice daily if taken with medications that increase the levels of Selzentry, such as boosted protease inhibitors (except for Aptivus), Stribild, Genvoya, Tybost, Rescriptor, clarithromycin, and itraconazole; 300 mg twice daily if taken with Aptivus, Viramune, Isentress, Tivicay, Triumeq, Fuzeon, and all of the NRTIs and medications that do not affect the levels of Selzentry; and 600 mg twice daily if taken with medications that decrease the levels of Selzentry, such as Atripla, Sustiva, Intelence, rifampin, and some anti-convulsants such as carbamazepine (Tegretol), phenobarbital, and phenytoin (Dilantin). Likely dose with rifapentine is 600 mg twice daily, but use with caution. Not recommended with St. John’s wort. Selzentry may be co-administered with the hepatitis C medication Harvoni at a dose of 300 mg twice daily; however, ledipasvir (in Harvoni) may have potential to increase Selzentry levels. Tell your provider or pharmacist about all medications, herbals, and supplements you are taking or thinking of taking, prescribed or not, as there are other drug interactions which are not listed here.
Not recommended by DHHS as a component of an initial regimen due to requirement of CCR5 tropism prior to initiation of therapy, lack of virologic benefit when compared to other recommended regimens, and because it requires twice-daily dosing.
Selzentry is generally recommended only when other HIV medications from other classes cannot be used or when a new class of medication is needed to construct a complete and durable treatment regimen for patients who have drug resistance. Complex dosing, the need for a tropism test, and competition from newer drugs have dimmed some of the initial enthusiasm for this drug. Selzentry appears to be synergistic with Trogarzo for people with extensive HIV drug resistance. See ibalizumab page. A tropism assay (Trofile, Trofile DNA, or HIV-1 Coreceptor Tropism with Reflex to UDS) is needed to determine if this medication will work for you. Results of a phenotypic tropism test (Trofile or Trofile DNA) may take up to a month to complete. Genotypic tests are also available and may provide a faster and less expensive alternative. Selzentry only works for those people with CCR5-tropic virus. Viral tropism refers to the types of HIV that a person can have, CCR5 (R5), CXCR4 (X4), or Dual-Mix Tropic (R5 and X4). Selzentry blocks CCR5, a receptor on the outside of a CD4 cell, and shuts down this point of entry for the virus. Most people are infected with R5 virus initially, and then over time, X4 and mixed viruses may predominate. Blocking R5 with Selzentry does not cause a shift to X4 or negatively affect disease progression or CD4 count in people whose virus can use dual-mix. The tropism test needed is now generally paid for by public health departments, Medicare, and private insurances. ViiV may cover the payment for the Trofile test under certain circumstances. Selzentry seems to have minimal impact on lipid levels. DHHS guidelines do not recommend the use of maraviroc in treatment-naïve pregnant women. Women who become pregnant while taking maraviroc may continue if viral suppression is effective and the regimen is well tolerated. The pharmacokinetics of maraviroc are not significantly altered during pregnancy and no dosage adjustment is necessary. Maraviroc is known to have a moderate level of transfer across the human placenta, although insufficient data exists to evaluate the effects on a fetus. Providers are encouraged to enroll pregnant women exposed to antiretroviral medications as early in pregnancy as possible in the Antiretroviral Pregnancy Registry (800-258-4263; apregistry.com).
Dr. Ross Slotten says:
Why include this medication in the Drug Guide? It is not a first-line agent because not everyone can take it. Only those with a so-called CCR5 tropic virus will benefit from it; those with a CXCR4 or dual-tropic virus will not respond to it. That makes testing for susceptibility complicated and expensive. It also interacts with boosted PIs and INSTIs and other medications, so its dose has to be adjusted, which is a pain in the neck. It belongs to the entry inhibitor class of HIV medications, related to Fuzeon (enfuvirtide), which rose quickly to fame after its approval in 2003 before fizzling out because it has to be injected twice daily and causes unpleasant injection site reactions. Otherwise, Fuzeon has very few side effects, its high tolerability being a significant virtue. At the time, Fuzeon offered a life-saving alternative agent for people with HIV who had failed a good number of previous regimens. Too bad it can’t be given orally. Selzentry, far fussier than Fuzeon, will remain a niche drug, useful primarily for those who have failed multiple anti-HIV regimens.
Activist Bridgette Picou says:
Selzentry (maraviroc) is in the entry inhibitor class of HIV medications and because of its mechanism of action is beneficial for the treatment-experienced because of how HIV adapts in the body. Selzentry works as a CCR5 antagonist to help block the virus from entering the cell. Once a person has been on medication therapy the virus may adapt to target a different entry point—CXCR4—which means Selzentry loses its advantage. There is a blood test that helps determine CCR5 activity. Dose adjustments are needed with some medications, including some HIV meds, so discuss all prescribed medications and remember to let your provider know if these changes or others are added after starting Selzentry.