Ritonavir dosage

Kilby JM, Hill A Buss N. The effect of ritonavir on saquinavir plasma concentration is independent of ritonavir dosage combined analysis of pharmacokinetic data from 97 subjects. HIV Med (2002) 3, 97-104. 

Bonafe SM, Costa DA, Vaz MJ, Senise JF, Pott-Junior H, Machado RH, et al. A randomized controlled trial to assess safety, tolerabiUty, and antepartum viral load with increased lopinavir/ritonavir dosage in pregnancy. AIDS Patient Care STDS 2013 27(ll) 589-95. 

Ritonavir (RTV) 100-mg caps, 600 mg bid No dosage adjustment in Take with food Gl intolerance, nausea, diarrhea CYP3A4 greater tha... 

Concomitant mecf/caf/ons - The dosage of vardenafil may require adjustment in patients receiving certain CYP3A4 inhibitors. For ritonavir, do not exceed a single dose of 2.5 mg vardenafil in a 72-hour period. For indinavir, ketoconazole 400 mg/day, and itraconazole 400 mg/day, do not exceed a single dose of 2.5 mg vardenafil in a 24-hour period. For ketoconazole 200 mg/day, itraconazole 200 mg/day, and erythromycin, do not exceed a single dose of 5 mg vardenafil in a 24-hour period. 

Adults The recommended dosage is 600 mg twice daily. Start ritonavir at no less than 300 mg twice daily and increase at 2 to 3 days intervals by 100 mg twice daily. 

If saquinavir and ritonavir are used in combination, reduce the dosage of saquinavir by 400 mg twice daily. 

Children The recommended dosage of ritonavir is 400 mg/m twice daily by mouth and should not exceed 600 mg twice daily. Start ritonavir at 250 mg/m and increase at 2- to 3-day intervals by 50 mg/m twice daily. Administer oral solution dose using a calibrated dosing syringe. 

Concomitant therapy - If amprenavir and ritonavir are used in combination, the recommended dosage regimens are the following Amprenavir 1200 mg with ritonavir 200 mg once daily or amprenavir 600 mg with ritonavir 100 mg twice daily. 

Therapy-naive patients-The recommended dosage is 400/100 mg of lopinavir/ritonavir (3 capsules or 5 mL taken with food, or 2 tablets taken with or without food) twice daily or 800/200 mg of lopinavir/ritonavir (6 capsules or 10 ml taken with food, or 4 tablets with or without food) once daily. 

Children (6 months to 12 years of age) The recommended dosage of lopinavir/ritonavir oral solution is 12/3 mg/kg for those weighing 7 to less than 15 kg and 10/2.5 mg/kg for those 15 to 40 kg (approximately equivalent to 230/57.5 mg/m ) twice daily with food, up to a maximum dose of 400/100 mg in children greater than 40 kg (5 mL or 3 capsules, or 2 tablets) twice daily. It is preferred that the prescriber calculate the appropriate milligram dose for each individual child 12 years of age and younger and determine the corresponding volume of solution or number of capsules or tablets. 

Lopinavir/Ritonavir Pediatric Dosage Without Efavirenz or Nevirapine... 

HIV infection (in combination with other antiretrovirals) PO 800 mg (two 400-mg capsules) q8h. Dosage adjustments when given concomitantly Delavirdine, itraconazole, ketoconazok Reduce dose to 600 mg q8h. Efavirenz-. Increase dose to 1,000 mg q8h. Lopinavir/ritonavir Reduce dose to 600 mg twice a day. Nevirapine-. Increase dose to 1,000 mgqSh. Rifabutin-. Reduce rifabutin by lA and increase indinavir to 1,000 mg q8h. Ritonavir 100-200 mg twice a day and indinavir 800 mg twice a day or ritonavir 400 mg twice a day and indinavir 400 mg twice a day. 

Dosage adjustments in comhination therapy Amprenavir. Amprenavir 1,200 mg and ritonavir 200 mg once a day or amprenavir 600 mg and ritonavir 100 mg twice a day. Am-penavirandefavirenz. Amprenavir 1,200 mg twice a day and ritonavir 200 mg twice a day with standard dose of efavirenz. Indinavir. Indinavir 800 mg twice a day and ritonavir 100-200 mg twice a day or indinavir400 mg twice a day and ritonavir 400 mg twice a day. Nelfinavirorsaquinavir. Ritonavir 400 mg twice a day. Rifabutin. Decrease rifabutin dosage to 150 mg every other day. 

HIV infection in combination with other antiretrovirals PO (Fortovase) 1,200 mg 3 times a day or 1,000 mg twice a day in combination with ritonavir 100 mg twice a day. PO (Invirase) 1,000 mg (5X200 mg or 2X500 mg) twice a day in combination with ritonavir 100 mg twice a day. Dosage adjustments when given in combination therapy Delavirdine Fortovase 800 mg 3 times a day Lopinavir/ritonavir-. Fortovase 800 mg twice a day Nelfinavir. Fortovase 800 mg 3 times a day or 1,200 mg twice a day. Ritonavir. Fortovase or Invirase 1,000 mg twice a day... 

Healthy volunteers were given protease inhibitors and statins, and the authors concluded that simvastatin should be avoided and that atorvastatin could be used with caution in people taking ritonavir and saquinavir (111). Dosage adjustment of pravastatin may be necessary with co-administration of ritonavir and saquinavir. Pravastatin does not alter the pharmacokinetics of nelfinavir, and thus appears to be safe for co-administration. 

Zhang, G.G. Law, D. Schmitt, E.A. Qiu, Y. Bauer, M. Bauer, J. Spanton, S. Henry, R. Quick, J. Dziki, W. Porter, W. Morris, J. Highleyman, L. Phase transformation considerations during process development and manufacture of solid oral dosage forms [Crystallization and solid state properties of molecules of pharmaceutical interest] Ritonavir an extraordinary example of conformational polymorphism Ritonavir manufacturing problems. Adv. Drug. Deliv. Rev. 2004, 56 (3), 371-390. 

Within 4 days of the introduction of ritonavir in a 49-year-old woman taking carbamazepine 600 mg/day the serum carbamazepine concentration rose from 29 to 84 pmol/l and ataxia occurred (88). The dosage of carbamazepine was reduced to 300 mg/day and the serum concentration fell but then rose again. Finally, a serum carbamazepine concentration in the target range was achieved with a dosage of 100 mg/day. 

In studies of combining ritonavir with fluconazole (2) and ritonavir with mefloquine (3) there were no significant effects, and dosage adjustment is not warranted. 

Withdrawal sjmptoms, and the need to increase the dose of methadone, in a 51-year-old man previously stable on a maintenance dosage, have been attributed to ritonavir (30). 

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