Names and pronunciation
(ri-toe′na-veer) Norvir
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Individual generic drug information
Extracted information for ritonavir only.
(ri-toe′na-veer) Norvir
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Func. class.: Antiretroviral
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Chem. class.: Protease inhibitor
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Do not confuse: ritonavir/Retrovir
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ACTION: Inhibits human immuno deficiency virus (HIV-1) protease and prevents maturation of the infectious virus
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USES: HIV-1 in combination with at least 2 other antiretrovirals
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Extracted information for ritonavir only.
CONTRAINDICATIONS: Hyper sensitivity
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Black Box Warning: Coadministration with other drugs Precautions: Pregnancy, breastfeeding, hepatic disease, pancreatitis, diabetes, hemophilia, AV block, hypercholesterolemia, immune reconstitution syndrome, neonates, cardiomyopathy, immune reconstitution syn- drome, infants 1-6 mo (overdose) Black Box Warning: Increase: toxicity— amiodarone, astemizole, azole antifungals, benzodiazepines, buPROPion, CISapride, cloZAPine, desipramine, dihydroergot- amine, encainide, ergotamine, flecainide, HMG-CoA reductase inhibitors, interleukins, meperidine, midazolam, pimozide, piroxi- cam, propafenone, propoxyphene, quiNI- Dine, ranolazine, saquinavir, terfenadine, triazolam, zolpidem; CYP2D6 inhibitors Black Box Warning: Increase: QT pro- longation—class IA/III antidysrhythmics, some phenothiazines, β-agonists, local anesthetics, tricyclics, haloperidol, chlo- roquine, droperidol, pentamidine, CYP3A4 inhibitors (amiodarone, clarithromycin, dasatinib, erythromycin, telithromycin, troleandomycin), arsenic trioxide, CYP3A4 substrates (methadone, pimozide, QUEtia- pine, quiNIDine, risperiDONE, ziprasidone) Increase: ritonavir levels—fluconazole Increase: level of both products—cla rithromycin, ddI Increase: levels of—bosentan Decrease: ritonavir levels—rifamycins, nevirapine, barbiturates, phenytoin Decrease: levels of anticoagulants, atova- quone, divalproex, ethinyl estradiol, lamoTRIgine, phenytoin, sulfamethoxa- zole, theophylline, voriconazole, zidovudine Drug/Herb Decrease: ritonavir levels—St. John’s wort; avoid concurrent use • Avoid use with red yeast rice Drug/Lab Test Increase: AST, ALT, K, CK, cholesterol, GGT, triglycerides, uric acid Decrease: Hct, HB, RBC, neutrophils, WBC Black Box Warning: To avoid OTC, prescription medications, herbs, supple- ments unless approved by prescriber; not to use St. John’s wort because it de- creases product’s effect • That regular follow-up exams and blood work will be required R HIGH ALERT
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SIDE EFFECTS CNS: Paresthesia, headache, seizures, fever, dizziness, insomnia, asthenia, intracranial bleeding CV: QT, PR interval prolongation GI: Diarrhea, buccal mucosa ulceration, abdominal pain, nausea, taste perversion, dry mouth, vomiting, anorexia, pancreatitis, CDAD, hepatitis INTEG: Rash MISC: Asthenia, angioedema, anaphy- syndrome, laxis, Stevens-Johnson increase lipids, lipodystrophy, toxic epidermal necrolysis, immune reconsti- tution syndrome MS: Pain, rhabdomyolysis, myalgia HEMA: Leukopenia, thrombocytopenia
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INTERACTIONS
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Extracted information for ritonavir only.
DOSAGE AND ROUTES HIV in combination • Adult/adolescent >16 yr: PO 600 mg bid; if nausea occurs, begin at 1⁄2 dose and gradually increase, max 1200 mg/ day in divided doses • Adolescent ≤16 yr: PO 350-400 mg/ m2 bid; increase by 50 mg/m2 bid q2- 3days, max 600 mg bid • Child: PO Initial 250 mg/m2 twice daily, then increase by 50 mg/m2 every 2-3 days to maintenance of 350-400 mg/ m2 twice daily, max 600 mg twice daily.
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Available forms: Oral sol 80 mg/mL; tab 100 mg; oral powder 100 mg
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Administer: Tablet • Take with food, swallow whole; do not crush, break, chew • When switching from cap to tab, more GI symptoms may occur, will lessen over time • Use dosage titration to minimize side effects • Store caps in refrigerator • Oral sol: shake well, use calibrated measuring device • Mix liquid formulation with chocolate milk or liquid nutritional supplement to improve taste • Oral powder: Prepare using number of packets needed, pour and mix entire contents over soft food or mix in 4 ounces of liquid • Overdose: infants, children, 43.2% al- cohol, 26.57% propylene glycol oral sol, calculate total amount of alcohol, propyl- ene glycol from all products given
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Extracted information for ritonavir only.
Assess: • HIV: viral load, CD4 at baseline, throughout therapy; blood glucose, plasma HIV RNA, serum cholesterol/ lipid profile; resistance testing before starting therapy and after treatment fail- ure • Immune reconstitution syndrome: may occur with combination therapy; may develop inflammatory response with op- portunistic infection (MAC, Graves’ dis- ease, Guillain-Barré syndrome, TB, PCP); may occur during initial treatment or months after • Signs of infection, anemia • Hepatic studies: ALT, AST in those with hepatic disease, monitor q3mo • Bowel pattern before, during treat- ment; if severe abdominal pain with bleeding occurs, discontinue product; monitor hydration • Skin eruptions; rash • Rhabdomyolysis: muscle pain, in- creased CPK, weakness, swelling of af- fected muscles, dark urine; if these occur and if confirmed by CPK, product should be discontinued • QT prolongation: ECG for QT prolonga- tion, ejection fraction; assess for chest pain, palpitations, dyspnea • Serious skin disorders: Stevens- Johnson syndrome, angioedema, anaphy- laxis, toxic epidermal necrolysis • Pregnancy/breastfeeding: use only if benefits outweigh fetal risk; enroll pregnant women in the Antiretroviral Pregnancy Reg- istry, 1-800-258-4263; do not breastfeed
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Evaluate: • Therapeutic response: improvement in HIV symptoms; improving viral load, CD4+ T cells
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • To take as prescribed; if dose is missed, to take as soon as remembered up to 1 hr before next dose; not to dou- ble dose • That product not a cure for HIV; that opportunistic infections may continue to be acquired • That redistribution of body fat or ac- cumulation of body fat may occur • That others may continue to contract HIV from patient
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Extracted information for ritonavir only.
PHARMACOKINETICS Well absorbed, 98% protein binding, hepatic metabolism, peak 2-4 hr, termi- nal half-life 3-5 hr
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Filter the extracted dose blocks for this individual drug.
HIV in combination
• Adult/adolescent >16 yr: PO 600 mg bid; if nausea occurs, begin at 1⁄2 dose and gradually increase, max 1200 mg/ day in divided doses
Candidate age grouping · source page 1168
HIV in combination
• Adolescent ≤16 yr: PO 350-400 mg/ m2 bid; increase by 50 mg/m2 bid q2- 3days, max 600 mg bid
Candidate age grouping · source page 1168
HIV in combination
• Child: PO Initial 250 mg/m2 twice daily, then increase by 50 mg/m2 every 2-3 days to maintenance of 350-400 mg/ m2 twice daily, max 600 mg twice daily.
Candidate age grouping · source page 1168