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Nelfinavir: Safety warnings lifted
In 2007, nelfinavir (Viracept) manufactured in Europe was recalled from the market after high levels of a byproduct, ethyl methane mesylate (EMS), were detected. Nelfinavir manufactured in the United States was found to have lower levels of EMS than the European product; however, the U.S. Food and Drug Administration (FDA) recommended that pregnant women not be treated with nelfinavir, and that pediatric patients not be initiated on nelfinavir. Following this, new safety standards for EMS were instituted, and in May 2008, the U.S. manufacturer, Pfizer, announced that these standards had been met. The European Medicines Agency had lifted its safety warnings about nelfinavir late in 2007. Currently, nelfinavir may be used in all patient populations.
The DHHS Guidelines on the treatment of pregnant women and of pediatric patients have been revised to include new recommendations on nelfinavir.
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Tipranavir: Approved for pediatric patients
In June, the FDA approved tipranavir (Aptivus) for use in pediatric patients aged 2-18 years and approved an oral solution of tipranavir (100 mg/mL). The recommended dosage, based on body weight, is tipranavir 14 mg/kg BID + ritonavir 6 mg/kg BID (or, based on body surface area, tipranavir 375 mg/m2 BID + ritonavir 150 mg/m2 BID), not to exceed tipranavir 500 mg BID + ritonavir 200 mg BID.
As in adults, tipranavir must be used in combination with ritonavir and other ARV medications and should be used only in treatment-experienced patients with resistance to more than one other PI.
Tipranavir has significant interactions with many other medications, including other ARVs. Information on drug interactions should be consulted before tipranavir is prescribed, as dosage adjustments are frequently required and some combinations are contraindicated.
Tipranavir solution contains vitamin E at a dose of 116 IU/mL; this source of vitamin E should be considered if vitamin E supplementation is planned.
The oral solution should be stored at 77°F (25°C).
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Lopinavir/ritonavir: Approved for infants
In June, the FDA approved lopinavir/ritonavir (Kaletra) for use in infants aged 14 days to 6 months. The oral solution (80 mg lopinavir/20 mg ritonavir per mL) should be used. The recommended dosage based on body weight is 16/4 mg/kg BID; based on body surface area, the dosage is 300/75 mg/m2 BID of the oral solution. No pharmacokinetic data are available on interactions between lopinavir/ritonavir and other medications in infants; until information about dosage adjustments in infants is available, lopinavir/ritonavir should not be given concomitantly with NNRTIs or other interacting medications.
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Nevirapine: Pediatric dosing
The U.S. manufacturer of nevirapine, Boehringer Ingelheim, has issued new dosing recommendations for nevirapine in pediatric patients older than 14 days. It is now recommended that dosage for all pediatric patients should be based on body surface area rather than on weight. The recommended dosage is 150 mg/m2 once daily for the first 14 days, then 150 mg/m2 twice daily. The maximum total daily dose is 400 mg. This method of determining pediatric dosages is intended to provide a single dosing strategy for pediatric patients of all ages, unlike the weight-based strategy.
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