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The Protease Inhibitors (PIs) |
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Detailed Prescribing Information |
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October 2005 |
| Ritonavir = Norvir | |
| Dosing Forms | 100 mg capsules (refrigerate) and suspension 125 mg/cc (nonrefrigerated) |
| Storage | Optimally store ritonavir soft gel caps in the refrigerator. If necessary ritonavir soft gel caps may be stored outside of a refrigerator for up to 30 days if the ambient temperature is < 77 deg Fahrenheit. |
| Dosing |
In boosting strategy: 100-200 mg once
or twice a day depending on the regimen (see
PI
Boosting chart for further info) Used as active protease inhibitor: over 1-2 weeks, gradually increase dose from 3x100 mg twice a day to 6x100 mg twice a day with food (see usage suggestions below) |
| Adverse Effects |
High incidence of GI
intolerance (abdominal pain and diarrhea) severely limits the ability to
use this drug as an active PI especially in patients who are already ill
with concomitant GI disease. Also perioral paresthesia, hyperlipidemia, fat redistribution, Type II diabetes |
| Interactions |
Probably more interactions
than any other drug. Favorable interaction with most other PIs makes this drug the ideal PI booster. It is usually not an active PI when used this way.
Voriconazole levels are reduced to
subtherapeutic levels. Levels of all erectile dysfunction drugs are increased: the lowest dose of these drugs must be used as a maximum and at intervals not be be decreased beyond every 48-72 hours. |
| Drugs of abuse/addiction: MDMA levels are increased and severe reactions/deaths have been reported. | |
| Suggested laboratory evaluations |
Liver profile and glucose monthly x 3
months, then every 3-4 months Lipid profile q3-4 months |
| Contraindications |
Antiarrhythmics: amiodarone, bepridil,
flecainide, propafenone, quinidine
Ergot Derivatives: dihydroergotamine,
ergonovine, ergotamine, methylergonivine
GI Motility Agent: cisapride
Herbal Products: St. John's wort (hypericum
perforatum)
HMG-CoA Reductase Inhibitors: lovastatin,
simvastatin
Neuroleptic: pimozide
Sedative/hypnotics: midazolam, triazolam
Antifungal: voriconazole |
| Warnings |
Examine patient's concomitant
medications carefully before prescribing. Ritonavir is generally regarded as too toxic to be used as an active single protease inhibitor. |
| Usage Suggestions |
Ritonavir is used nearly exclusively as an inhibitor of the metabolism of other protease inhibitors
i.e. as a "boosting" agent. High dose ritonavir is usually too toxic and other agents such as indinavir and lopinavir/ritonavir have comparable potency as well as the ability to overcome some degree of protease inhibitor resistance. |
| Full Prescribing Information | http://www.norvir.com |
| Links to Antiretroviral Sections (click on anything) |
| Nucleoside & Nucleotide Reverse Transcriptase Inhibitors (NRTI) |
| AZT | ddC | ddI | d4T | 3TC | ABC | FTC | TDF | Combivir | Trizivir | Epzicom | Truvada |
| Nonnucleoside Reverse Transcriptase Inhibitors (NNRTI) |
| efavirenz | nevirapine | delavirdine |
| Protease Inhibitors (PI) | Boosted Protease Inhibitors |
| saquinavir | indinavir | ritonavir | nelfinavir | amprenavir | lopinavir + ritonavir | atazanavir | fosamprenavir | tipranavir |
| Fusion Inhibitors |
| enfuvirtide |
Updated 10.25.2005
