FDA approves new tablet formulation of Norvir (ritonavir)
On February 10, 2010, FDA approved Norvir (ritonavir) 100 mg Tablets. These tablets do not require refrigeration.
Summarized below are highlights from the new Norvir Tablet package insert.
Unlike the capsule formulation, Norvir tablets must be taken with meals. As a result, Section 2 DOSAGE AND ADMINISTRATION contains the following information specific to the tablet formulation.
NORVIR is administered orally. NORVIR tablets should be swallowed whole, and not chewed, broken or crushed.
General Dosing Guidelines
Patients who take the 600 mg twice daily soft gel capsule NORVIR dose may experience more gastrointestinal side effects such as nausea, vomiting, abdominal pain or diarrhea when switching from the soft gel capsule to the tablet formulation because of greater maximum plasma concentration (Cmax) achieved with the tablet formulation relative to the soft gel capsule [see Clinical Pharmacology (12.3)]. Patients should also be aware that these adverse events (gastrointestinal or paresthesias) may diminish as therapy is continued.
Dose Modification for NORVIR
Dose reduction of NORVIR is necessary when used with other protease inhibitors: amprenavir, atazanavir, darunavir, fosamprenavir, saquinavir, and tipranavir.Prescribers should consult the full prescribing information and clinical study information of these protease inhibitors if they are co-administered with a reduced dose of ritonavir.
2.1 Adult Patients
Recommended Dosage for Treatment of HIV-1.
The recommended dosage of ritonavir is 600 mg twice daily by mouth to be taken with meals.
In Section 12.3, Pharmacokinetic,s the following information regarding the tablet formulation was included.
NORVIR tablets are not bioequivalent to NORVIR capsules. Under moderate fat conditions (857 kcal; 31% fat, 13% protein, 56% carbohydrates), when a single 100 mg NORVIR dose was administered as a tablet compared with a capsule, AUC(0- ∞) met equivalence criteria but mean Cmax was increased by 26% (92.8% confidence intervals: ↑15 -↑39%).
No information is available comparing NORVIR tablets to NORVIR capsules under fasting conditions
Effect of Food on Oral Absorption
A food effect is observed for NORVIR tablets. Food decreased the bioavailability of the ritonavir tablets when a single 100 mg dose of NORVIR was administered. Under high fat conditions (907 kcal; 52% fat, 15% protein, 33% carbohydrates), a 23% decrease in mean AUC(0-∞) [90% confidence intervals: ↓30%-↓15%], and a 23% decrease in mean Cmax [90% confidence intervals: ↓34%-↓11%]) was observed relative to fasting conditions. Under moderate fat conditions, a 21% decrease in mean AUC(0-∞) [90% confidence intervals: ↓28%-↓13%], and a 22% decrease in mean Cmax [90% confidence intervals: ↓33%-↓9%]) was observed relative to fasting conditions.
However, the type of meal administered did not change ritonavir tablet bioavailability when high fat was compared to moderate fat meals.
Section 16 “HOW SUPPLIED/STORAGE AND HANDLING.” is updated to contain the following information:
16.1 NORVIR Tablets, 100 mg Ritonavir
NORVIR (ritonavir) tablets are white film-coated ovaloid tablets debossed with the corporate Abbott "A" logo and the Abbo-Code NK.
Bottles of 30 tablets each (NDC 0074-3333-30).
Store NORVIR film-coated tablets at 20°-25°C (68°-77°F); excursions permitted to 15°-30°C (59°-86°F) [see USP controlled room temperature]. Dispense in original container or USP equivalent tight container (60 mL or less). For patient use: exposure of this product to high humidity outside the original or USP equivalent tight container (60 mL or less) for longer than 2 weeks is not recommended
Norvir is a product of Abbott Laboratories.
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