Standard DoseOne 100 mg tablet once daily without regard to food in combination with other antiretroviral drugs in people taking HIV treatment for the first time (treatment-naïve) or to replace the current antiretroviral regimen in those who are virologically suppressed (HIV viral load less than 50 copies/mL) on a stable antiretroviral regimen with no history of treatment failure and no known viral substitutions associated with resistance to doravirine. Must be taken in combination with another antiretroviral(s) which does not contain this medication or medication from the same drug class.
Approved only for adults at this time. Take missed dose as soon as possible, unless it is closer to the time of your next dose. Do not double up on your next dose. No dosage adjustment necessary for mild, moderate, or severe kidney impairment or for mild or moderate liver impairment. Pifeltro has not been studied in patients with severe liver impairment.
See package insert for more complete information on potential side effects and interactions.
ManufacturerMerck and Co.
Potential Side Effects and Toxicity
Most common side effects observed with Pifeltro in studies were nausea (7%), dizziness (7%), headache (6%), fatigue (6%), diarrhea (5%), abdominal pain (5%), and abnormal dreams (1%). Rash, which is a common side effect of the NNRTIs, was reported in up to 2% of the studied population. In one study (DRIVE-AHEAD), an in-depth analysis was conducted of the incidence of neuropsychiatric adverse events associated with a doravirine-containing regimen (Delstrigo) compared to Atripla. Neuropsychiatric events, such as depression, sleep disturbances, and dizziness, are another common side effect of the NNRTI class. Doravirine did not appear to negatively affect cholesterol in studied populations.
Most common side effects (at least 5% of people taking it) observed with Pifeltro in studies were nausea (7%), dizziness (7%), headache (6%), fatigue (6%), diarrhea (5%), abdominal pain (5%), abnormal dreams (1%), and increased bilirubin (5%). Rash, which is a common side effect of the NNRTIs, was reported in up to 2% of the studied population. In one study (DRIVE-AHEAD), an in-depth analysis was conducted of the incidence of neuropsychiatric adverse events associated with a doravirine-containing regimen (Delstrigo) compared to Atripla. Neuropsychiatric events, such as depression, sleep disturbances, and dizziness, are another common side effect of the NNRTI class. Doravirine did not appear to negatively affect cholesterol in studied populations.
Potential Drug Interactions
New interactions continue to be discovered after drug approval. When using with the antibiotic drug rifabutin (used for TB and MAC treatment), increase the Pifeltro dose to one tablet twice a day, approximately every 12 hours. The following are among the medications that may lower the blood levels of Pifeltro, and therefore may decrease its effectiveness, and should not be used with Pifeltro: the anticonvulsants carbamazepine, oxcarbazepine, phenobarbital, and phenytoin; the androgen receptor inhibitor enzalutamide; the antimycobacterials rifampin and rifapentine; the cytotoxic agent (cancer drug) mitotane; and the herbal St. John’s wort. 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.
Received FDA approval in 2018. Doravirine may be an option for patients who have developed drug resistance to other NNRTIs. A single-tablet regimen (STR) containing doravirine was also approved in 2018; see Delstrigo page. Delstrigo, however, contains the older version of tenofovir, tenofovir DF. The stand-alone Pifeltro allows people to take it with the newer tenofovir alafenamide, or TAF (found in Descovy), which has potentially less renal and bone toxicity. On the other hand, of course, the use of Pifeltro means the necessity for an extra pill, such as Descovy, or maybe more than one extra pill, depending on the regimen being used. Pifeltro was found to be non-inferior to boosted darunavir (Prezista) as well as efavirenz (Sustiva) at 48 weeks. Doravirine was superior to boosted darunavir at week 96 in terms of virologic suppression, but it should be noted there was a higher rate of study discontinuation in the boosted darunavir group. Doravirine is a non-nucleoside medication, and it should be noted that this class of drugs typically has a lower barrier to resistance as well as has extensive cross-resistance. Additionally, the emergence of resistance at the time of virologic failure has been reported with doravirine. Doravirine has tolerability advantages over efavirenz and has relatively favorable lipid effects when compared with both boosted darunavir and efavirenz. It also has fewer potential drug interactions than efavirenz or rilpivirine, and, unlike rilpivirine, virologic efficacy is not compromised in those with high baseline viral loads or low CD4 counts. Doravirine has not been directly compared to integrase inhibitor-based regimens in clinical trials yet. Pifeltro now has a switch indication, so that people with undetectable viral load on a stable HIV treatment can switch to a regimen that includes Pifeltro if they have no drug resistance to it and no history of treatment failure.
Dr. Ross Slotten says:
Pifeltro (doravirine) was approved by the FDA in August 2018 as another second generation NNRTI, like rilpivirine and etravirine (Intelence). It is taken once daily, has few side effects, and may be effective if a person is resistant to the first generation NNRTIs, efavirenz and nevirapine. However, like efavirenz and nevirapine, it has a relatively low barrier to resistance and resistance to it has already been reported. One virtue is that it can be taken with food or on an empty stomach, like bictegravir, dolutegravir, and raltegravir. It is primarily being promoted as part of the three-drug regimen, Delstrigo.
Activist Bridgette Picou says:
Pifeltro (doravirine) has no restrictions on CD4 count or viral load and is indicated for individuals starting therapy for the first time, and also as a switch regimen for persons stable and surpressed on current therapy. It should be taken with other ART medications and seems to be well tolerated. Additionally, it does not have the restrictions for use with proton pump inhibitors (antacids). Pifeltro is part of the single-tablet regimen Delstrigo. It seems to be well tolerated.