Ritonavir Dosage
This dosage information may not include all the information needed to use Ritonavir safely and effectively. See additional information for Ritonavir.
The information at Drugs.com is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.
Usual Adult Dose for:
Usual Pediatric Dose for:
Additional dosage information:
Usual Adult Dose for HIV Infection
As a pharmacokinetic booster for other protease inhibitors: 100 to 400 mg/day orally in 1 or 2 divided doses
FDA-approved dose:
Initial dose: 300 mg orally twice a day
Maintenance dose: Increase by 100 mg twice daily every 2 to 3 days to the full dose of 600 mg orally twice a day
Usual Pediatric Dose for HIV Infection
Greater than 1 month:
Initial dose: 250 mg/m2 orally twice a day
Maintenance dose: Increase by 50 mg/m2 twice daily every 2 to 3 days to the full dose of 350 to 400 mg/m2 orally twice a day
If 400 mg/m2 twice a day is intolerable, the highest tolerated dose may be used for maintenance therapy in combination with other antiretrovirals; however, alternative therapy should be considered.
Maximum: 600 mg/dose
Renal Dose Adjustments
No adjustment recommended.
Liver Dose Adjustments
Mild to moderate hepatic impairment: No adjustment recommended. Caution and clinical and laboratory monitoring is recommended in patients with preexisting liver disease, hepatitis, or abnormal liver enzymes.
Severe hepatic impairment: Not recommended.
Dose Adjustments
Ritonavir dose reduction is needed when used with other protease inhibitors (e.g., amprenavir, atazanavir, darunavir, fosamprenavir, saquinavir, and tipranavir). The full prescribing information and clinical study data of these protease inhibitors should be consulted if they are coadministered with a reduced dose of ritonavir.
Precautions
Ritonavir may potentially interact with many drugs. These interactions may be serious and/or life-threatening. Concurrent use with many drugs is either contraindicated, not recommended, or requires dosage adjustments. Contraindicated drugs include alfuzosin, amiodarone, flecainide, propafenone, quinidine, dihydroergotamine, ergonovine, ergotamine, methylergonovine, cisapride, pimozide, oral midazolam, triazolam, lovastatin, simvastatin, voriconazole, St. John's Wort, and sildenafil for treatment of pulmonary arterial hypertension. Patients should be advised to report all concurrent medications they are taking.
Pancreatitis has been observed in patients receiving ritonavir therapy, including those who developed hypertriglyceridemia. Patients who experience signs or symptoms of pancreatitis should be evaluated and ritonavir should be stopped if a diagnosis of pancreatitis is made.
Ritonavir therapy alone or in combination with saquinavir has resulted in large increases in the concentration of total cholesterol and triglycerides. Triglyceride and cholesterol testing are recommended before starting and periodically during therapy. Lipid disorders should be managed as clinically appropriate.
Allergic reactions (including urticaria, mild skin eruptions, bronchospasm, and angioedema) and cases of anaphylaxis, toxic epidermal necrolysis, and Stevens-Johnson syndrome have been reported. Treatment should be discontinued if severe reactions develop.
Ritonavir has been shown to prolong the PR interval in some patients. Caution and clinical monitoring are recommended in patients with underlying structural heart disease, preexisting conduction system abnormalities, ischemic heart disease, cardiomyopathy, or who are taking other drugs that may prolong the PR interval.
Episodes of hyperglycemia, new onset diabetes mellitus, and exacerbation of preexisting diabetes mellitus have been reported in patients receiving protease inhibitors. No causal relationship has been established. Careful monitoring of blood glucose levels should be done and either initiation or dose adjustments of insulin or oral hypoglycemic agents may be needed.
Spontaneous bleeding episodes have been reported in hemophiliac patients while receiving protease inhibitors. Hemophiliacs should be monitored closely for bleeding during therapy.
Immune reconstitution syndrome has occurred during combination antiretroviral therapy. Patients responding to therapy may develop an inflammatory response to indolent or residual opportunistic infections and require evaluation and treatment.
Ritonavir is frequently used (off-label) as a pharmacokinetic booster for some other protease inhibitors. It should generally not be added as a single agent when antiretroviral regimens are changed due to the development of drug resistance and loss of virological response. The labeling of the boosted protease inhibitor should be consulted for dosage recommendations.
Ritonavir oral solution contains 43% v/v ethanol.
The potential for HIV cross-resistance among protease inhibitors exists but has not been fully explored. It is unknown what effect ritonavir therapy will have on the activity of subsequently administered protease inhibitors. Selection of antiretroviral agents for a patient's medication regimen should be done carefully.
Safety and effectiveness have not been established in pediatric patients less than 1 month of age.
Dialysis
No adjustment recommended.
Other Comments
Ritonavir should be taken with meals. The maximum dose of 600 mg twice a day should not be exceeded upon completion of the titration.
Ritonavir tablets should be swallowed whole and not chewed, broken, or crushed. Patients who take the soft gel capsules may have more gastrointestinal side effects (such as nausea, vomiting, abdominal pain, or diarrhea) when switching to the tablet formulation. These side effects (gastrointestinal or paresthesias) may lessen with continued therapy.
The oral solution should be shaken well before use. The taste may be improved by mixing it with chocolate milk, Ensure(R), or Advera(R). The mixture should be taken within 1 hour and should be administered using a calibrated dosing syringe.
Refrigeration of the capsules by the patient is recommended, but not required if they are used within 30 days. The capsules should be protected from light and excessive heat.
