Overview
11 DESCRIPTION Ritonavir is an inhibitor of HIV protease with activity against the Human Immunodeficiency Virus (HIV). Ritonavir is chemically designated as 10-Hydroxy-2-methyl-5-(1-methylethyl)-1-[2-(1-methylethyl)-4-thiazolyl]-3,6-dioxo-8,11-bis(phenylmethyl)-2,4,7,12-tetraazatridecan-13-oic acid, 5-thiazolylmethyl ester, [5S-(5R*,8R*,10R*,11R*)].
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Ritonavir is an antiretroviral drug [see Microbiology (12.4) ] . 12.2 Pharmacodynamics Cardiac Electrophysiology QTcF interval was evaluated in a randomized, placebo and active (moxifloxacin 400 mg once-daily) controlled crossover study in 45 healthy adults, with 10 measurements over 12 hours on Day 3. The maximum mean (95% upper confidence bound) time-matched difference in QTcF from placebo after baseline correction was 5.5 (7.6) milliseconds (msec) for 400 mg twice-daily ritonavir. Ritonavir 400 mg twice daily resulted in Day 3 ritonavir exposure that was approximately 1.5 fold higher than observed with ritonavir 600 mg twice-daily dose at steady state.
Indications
- 1 INDICATIONS AND USAGE Ritonavir tablets are indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. Ritonavir tablets are HIV protease inhibitors indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection ( 1 )
Common Doses
- 600 mg
- 100 mg
- 300 mg
- 400 mg
Dosage
2 DOSAGE AND ADMINISTRATION Adult patients: 600 mg twice-day with meals ( 2.3 ) Pediatrics patients: The recommended twice daily dose for children greater than one month of age is based on body surface area and should not exceed 600 mg twice daily with meals ( 2.4 ) Ritonavir oral solution should not be administered to neonates before a postmenstrual age (first day of the mother’s last menstrual period to birth plus the time elapsed after birth) of 44 weeks has been attained ( 2.4 , 5.2 ) Ritonavir oral powder can only be used for dosing increments of 100 mg ( 2.
Black Box Warning
WARNING: DRUG-DRUG INTERACTIONS LEADING TO POTENTIALLY SERIOUS AND/OR LIFE THREATENING REACTIONS Co-administration of ritonavir with several classes of drugs including sedative hypnotics, antiarrhythmics, or ergot alkaloid preparations may result in potentially serious and/or life-threatening adverse events due to possible effects of ritonavir on the hepatic metabolism of certain drugs. Review medications taken by patients prior to prescribing ritonavir or when prescribing other medications to patients already taking ritonavir [see Contraindications (4) , Warnings and Precautions (5.1) ].
Contraindications
- 4 CONTRAINDICATIONS When co-administering ritonavir tablets with other protease inhibitors, see the full prescribing information for that protease inhibitor including contraindication information. Ritonavir tablets are contraindicated in patients with known hypersensitivity (e.g., toxic epidermal necrolysis (TEN) or Stevens-Johnson syndrome) to ritonavir or any of its ingredients. Ritonavir tablets are contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening reactions [see Drug...
Side Effects
- 6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the labeling. Drug Interactions [see Warnings and Precautions (5.1) ] Hepatotoxicity [see Warnings and Precautions (5.3) ] Pancreatitis [see Warnings and Precautions (5.4) ] Allergic Reactions/Hypersensitivity [see Warnings and Precautions (5.5) ] When co-administering ritonavir with other protease inhibitors, see the full prescribing information for that protease inhibitor including adverse reactions.
Interactions
- 7 DRUG INTERACTIONS When co-administering ritonavir with other protease inhibitors (atazanavir, darunavir, fosamprenavir, saquinavir, and tipranavir), see the full prescribing information for that protease inhibitor including important information for drug interactions. Co-administration of ritonavir can alter the concentrations of other drugs. The potential for drug-drug interactions must be considered prior to and during therapy (4 , 5.1 , 7 , 12.3) 7.