Norvir
Take missed dose as soon as possible (at the same time as the other PI prescribed) unless it’s closer to the time of your next dose. Do not double up on your next dose. Do not crush or chew; always swallow whole.
Approved for children older than one month with dosing based on body surface area; the use in children depends on the co-administered PI. Liquid formulation available (80 mg/mL) in peppermint caramel flavor, but it is not very palatable. The liquid’s taste can be improved by mixing with chocolate milk, peanut butter, Ensure or Advera within one hour of dosing. The liquid formulation should not be taken by individuals who are pregnant, as it contains 43% alcohol. Norvir oral powder available in 100 mg packets is free of alcohol and propylene glycol (both of which are found in the liquid formulation), and thus safer for pediatric use.
- Generic and brand name available for 150mg oral tablets. Brand name only available as Norvir 100mg oral packet.
- See package insert for more complete information on potential side effects and interactions.
norvir.com; (800) 633-9110
generic: $277.74
JO-ANN JOSE, MD, MPH:
Ritonavir is a protease inhibitor that acts against HIV but is only used now as a booster for certain protease inhibitors, most commonly darunavir. There are many drug interactions with ritonavir. If you’re on a regimen that contains ritonavir, it’s important to have detailed discussion with your care provider about all the medications, drugs and supplements you are taking or thinking of taking to learn of any potential drug interactions. The University of Liverpool maintains an online HIV drug interactions checker; go to hiv-druginteractions.org/checker.
There can be liver toxicity with Norvir; some studies found issues with rising triglyceride levels. The drug can also cause an unpleasant taste in your mouth. Most people don’t experience this odd side effect, but it can be an intense bitterness. Norvir is also quite a large pill, so if someone is on a darunavir-based regimen, I often see if I can possibly condense it into a combination pill. Ritonavir is also in the anti-COVID drug Paxlovid.
Norvir interacts with many drugs; check the package insert. Ritonavir is in the anti-COVID drug Paxlovid, which is only 5 days of treatment and therefore should not cause additional drug interactions. Of note, Norvir is not interchangeable with Tybost. Do not take with alfuzosin, amiodarone, cisapride, clopidogrel, dronedarone, eplerenone, flibanserin, flecainide, ivabradine, lomitapide, lumateperone, lurasidone, propafenone, oral midazolam, triazolam, pimozide, propafenone, quinidine, ranolazine, Revatio, rifapentine, rifampin, silodosin, suvorexant, ticagrelor, vorapaxar, voriconazole, ergot derivatives, ziprasidone or the herb St. John’s wort. Carefully weigh benefits of coadministering tamsulosin and monitor for possible side effects or adjust dose if indicated. Do not use lovastatin or simvastatin or co-formulations containing these drugs (Advicor and Vytorin) for the treatment of high cholesterol. Cholesterol-lowering alternatives are atorvastatin, rosuvastatin, pravastatin, pitavastatin and fluva-statin, but should be used with caution and started at the lowest dose possible; monitor for increased side effects. Norvir increases levels of nasal and inhaled fluticasone (found in Advair, Flonase, Breo Ellipta, Arnuity Ellipta and Flovent), which may lead to Cushing’s syndrome. Use an alternative corticosteroid and monitor for signs of Cushing’s syndrome (increased abdominal fat, fatty hump between the shoulders, rounded face, red/purple stretch marks, bone loss, increased appetite, possible high blood pressure and sometimes diabetes). Trazodone concentrations may increase; a lower dose of trazodone is recommended. Norvir may decrease levels of methadone, therefore titrate dose of methadone to clinical effect. Use caution with anticonvulsants such as carbamazepine, eslicarbazepine, oxcarbazepine, phenobarbital and phenytoin. Use calcium channel blockers (amlodipine, nifedipine and others) with caution. If coadministering with pimavanserin, buprenorphine or everolimus, a dose reduction may be required as well as additional monitoring. Norvir may alter warfarin levels; additional monitoring is required. Taking Norvir with most other blood thinners (anticoagulants), such as Xarelto, is not recommended; however, it can be used with apixaban (Eliquis) with monitoring and an adjusted dose of apixaban. Norvir can increase anticoagulant concentrations (and thereby increase risk of bleeding) or decrease their concentrations (and thereby decrease effectiveness). Cialis, Levitra and Viagra levels are increased; doses should not exceed 10 mg Cialis or 2.5 mg Levitra per 72 hours, or 25 mg Viagra per 48 hours. Do not use with avanafil. Monitor for increased side effects of these medications, such as visual disturbances, low blood pressure, dizziness and prolonged painful erection lasting longer than four hours. Effectiveness of oral contraceptives may be decreased; consider using other or alternative methods of contraception. Levels of the street drug ecstasy are greatly increased by Norvir, and at least one death has been attributed to the combination. Using Norvir with methamphetamines can result in up to a 2–3-fold increase in methamphetamine concentrations, increasing the risk for overdose. GHB, another street drug, as well as cocaine, are also dangerous with Norvir. Clarithromycin levels can increase by up to 80%. Co-administer bosentan, salmeterol and immunosuppressants with caution. If co-administered, a lower dose of colchicine is recommended. Do not coadminister with atazanavir and lenacapavir. Norvir, when combined with another PI, may be taken with Sovaldi, Daklinza (dose may need adjustment), Epclusa (monitor for tenofovir toxicity if TDF is part of regimen) and Harvoni (if TDF is not part of HIV regimen). Norvir + PI should not be taken with Olysio, Viekira Pak or Zepatier. Tell your provider or pharmacist about all medications, herbals and supplements you are taking or thinking of taking, prescribed or not, as there are many other drug interactions that are not listed here.
The side effect potential of Norvir is much lower now that it is only used as a booster at low doses. Most common side effects include stomach discomfort, nausea, diarrhea and vomiting. Other less common side effects may include fatigue; tingling/numbness around the mouth, hands or feet; loss of appetite and taste disturbances. Norvir can also increase cholesterol and triglyceride levels. Measure liver function before starting and then monitor, with perhaps closer monitoring for those with underlying liver problems, especially during the first several months. No dose adjustment necessary with mild to moderate liver disease, but Norvir is not recommended for those with severe liver impairment.
The advantage of Norvir is its use at low doses with other protease inhibitors (PIs) as a boosting agent (officially in the drug class called “pharmacokinetic enhancers”). As such, it’s used to increase the levels of some PIs. You can look up drug interactions at hiv-druginteractions.org. Stomach side effects are reduced by taking Norvir with high-fat foods.
JUAN MICHAEL PORTER II:
Norvir (ritonavir) is a booster drug—it raises the levels of other drugs, but it is not an HIV medication itself—given with a protease inhibitor. Early on, it was given at higher doses than appropriate, which caused terrible diarrhea. Though it’s now given once a day at 100 mg, no doctor I spoke to looked on it favorably because we are not using PIs unless necessary.