Nelfinavir suspension obtained from nelfinavir tablets has equivalent pharmacokinetic profile

Prevention of perinatal transmission of zidovudine- and nevirapine-resistant HIV

PURPOSE

The use of a three-drug regimen for the prevention of perinatal transmission of zidovudine- and nevirapine-resistant HIV is described.

SUMMARY

A 17-year-old Hispanic woman infected with HIV arrived at our clinic for the management of her first pregnancy. The patient was in her second trimester of her pregnancy, had not previously been treated with antiretroviral therapy, and was only taking daily prenatal vitamins at the time of her first clinic visit. Her HIV RNA viral load was 240 copies/mL, and the virus was resistant to both zidovudine and nevirapine. Nelfinavir (compounded suspension), lamivudine, and zidovudine were prescribed for the mother, though she was generally nonadherent to therapy. Nelfinavir, lamivudine, and zidovudine were initiated for the newborn within eight hours of delivery. Six months later, the patient returned to the clinic in the first trimester of her second pregnancy. At this visit, her HIV RNA viral load was 120 copies/mL. After the birth of her second child, the infant received the same regimen received by her firstborn: zidovudine 4 mg/kg orally twice daily for six weeks, lamivudine 2 mg/kg orally twice daily for two weeks, and nelfinavir 55 mg/kg orally twice daily for two weeks. At four months of age, each infant was found to be HIV-negative.

CONCLUSION

A prophylactic regimen that included nelfinavir, lamivudine, and zidovudine was used to prevent perinatal transmission of HIV in two neonates. The regimen was well tolerated, and both infants were determined to be HIV-negative at four months of age.

A HAART-Breaking Review of Alternative Antiretroviral Administration: Practical Considerations with Crushing and Enteral Tube Scenarios

Selection of an appropriate antiretroviral regimen for the patient infected with human immunodeficiency virus can be challenging, as various considerations must be taken into account including viral resistance mutations, patient comorbidities, drug interactions, and the potential for drug-related adverse effects and toxicities. Treatment is further complicated when a clinical scenario arises requiring an alteration in the dosage form. Factors ranging from dysphagia to administration through an enteral feeding tube can affect decisions regarding antiretroviral dosage forms. Limited pharmacokinetic data exist regarding the alteration of antiretroviral medications from their original form. Bioavailability may vary substantially between dosage forms, which can lead to unpredictable drug concentrations. Supratherapeutic or subtherapeutic antiretroviral drug concentrations can result in increased toxicity, virologic failure, or the emergence of drug resistance. We performed a systematic literature search to review the available antiretroviral literature on the modification of solid dosage forms as well as alternative routes of administration of oral antiretroviral agents and their application to clinical practice.

Alternative antiretroviral therapy formulations for patients unable to swallow solid oral dosage forms

PURPOSE

Evidence-based guidance is presented to assist clinicians in selecting alternative formulations of antiretroviral (ARV) agents for patients with human immunodeficiency virus (HIV) infection who are unable to swallow tablets or capsules.

SUMMARY

The inability to take medications in standard oral dosage forms can be associated with nonadherence or the use of alternative administration strategies such as capsule or tablet breaking, crushing, or chewing. Patients with HIV infection require long-term ARV therapy to maintain viral suppression; ARV agents are predominately available as tablets and capsules that may pose swallowing difficulties for some patients. Using a variety of sources (the primary literature, pharmaceutical package inserts, and requests for unpublished data from drug manufacturers), available evidence on the bioavailability of ARV medications after disruption of the capsule or tablet matrix was reviewed; information on alternative formulations of ARV agents was also assessed. With several ARV agents, disruption of the solid oral dosage form by crushing, chewing, or breaking tablets or opening capsules prior to ingestion has been shown to result in altered bioavailability or pharmacokinetics and thus the potential for incomplete virological suppression, increased adverse effects, and suboptimal health outcomes.

CONCLUSION

Of the 33 single-agent ARV medications and combination ARV products in five classes available at the time of review, approximately half exist as powders, liquids, injectables, or chewable or dissolvable tablets. If alternative ARV formulations or administration methods are used, close monitoring for achievement of virological and immunologic success and potential toxicities is recommended.

Tamoxifen enhances the cytotoxic effects of nelfinavir in breast cancer cells

Introduction

The HIV protease inhibitor nelfinavir is currently under investigation as a new anti-cancer drug. Several studies have shown that nelfinavir induces cell cycle arrest, endoplasmic reticulum stress, autophagy, and apoptosis in cancer cells. In the present article, the effect of nelfinavir on human breast cancer cells is examined and potential combination treatments are investigated.

Methods

The effects of nelfinavir and tamoxifen on the human breast cancer cell lines MCF7, T47 D, MDA-MB-453, and MDA-MB-435 were tested by analysing their influence on cell viability (via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay), apoptosis (annexin binding, poly(ADP-ribose) polymerase cleavage), autophagy (autophagy marker light chain 3B expression), endoplasmic reticulum stress (binding protein and activating transcription factor 3 expression), and the occurrence of oxidative stress (intracellular glutathione level).

Results

Nelfinavir induced apoptosis in all four breast cancer cell lines tested, although the extent of autophagy and endoplasmic reticulum stress varied among the cell lines. The concentration of nelfinavir needed for an efficient induction of apoptosis in breast cancer cells could be reduced from 15 μg/ml to 6 μg/ml when combined with tamoxifen. At a concentration of 6 μg/ml, tamoxifen substantially enhanced the endoplasmic reticulum stress reaction in those cell lines that responded to nelfinavir with binding protein (BiP) upregulation (MCF7, T47D), and enhanced autophagy in cell lines that responded to nelfinavir treatment with autophagy marker light chain 3B upregulation (MDA-MB-453). Although tamoxifen has been described to be able to induce oxidative stress at concentrations similar to those applied in this study (6 μg/ml), we observed that nelfinavir but not tamoxifen reduced the intracellular glutathione level of breast cancer cells within hours of application by up to 32%, suggesting the induction of oxidative stress was an early event and an additional cause of the apoptosis induced by nelfinavir.

Conclusions

The results demonstrate that nelfinavir may be an effective drug against breast cancer and could be combined with tamoxifen to enhance its efficacy against breast cancer cells. Moreover, the cytotoxic effect of a tamoxifen and nelfinavir combination was independent of the oestrogen receptor status of the analysed breast cancer cells, suggesting a potential benefit of a combination of these two drugs even in patients with no hormone-responsive tumours. We therefore recommend that clinical studies on nelfinavir with breast cancer patients should include this drug combination to analyse the therapeutic efficacy as well as the safety and tolerability of this potential treatment option.

A review of nelfinavir for the treatment of HIV infection

Nelfinavir (NFV) is a protease inhibitor that has been widely used for several years for the treatment of HIV infection. This has led to extensive experience with NFV-containing regimens, in which the drug has shown prolonged viral suppression, good tolerability and a unique resistance profile. In recent years, several antiretroviral drugs with some advantages over NFV have been developed. Nevertheless, NFV has favourable characteristics that make it a suitable antiretroviral compound for many HIV-infected patients. It can be used in patients who do not tolerate ritonavir even at low doses, and it is well tolerated in pregnant women, has a low-grade interaction with methadone and may be well tolerated in hepatitis C virus-co-infected patients. In addition, its new simplified posology may contribute to improved adherence.

Nelfinavir: a review of its use in the management of HIV infection

Nelfinavir (Viracept) is an orally administered protease inhibitor. In combination with other antiretroviral drugs (usually nucleoside reverse transcriptase inhibitors [NRTIs]), nelfinavir produces substantial and sustained reductions in viral load in patients with HIV infection. Nelfinavir may be used in the treatment of adults, adolescents and children aged >or=2 years with HIV infection. It can also be used in pregnancy. Resistance to nelfinavir may develop, but the most common mutation (D30N, appearing mainly in HIV-1 subtype B) does not confer resistance to other protease inhibitors, thereby conserving these agents for later use. Although less effective than lopinavir/ritonavir, the preferred first-line treatment in US guidelines, nelfinavir is positioned as an alternative agent for the treatment of adults and adolescents with HIV infection and is an option for those unable to tolerate other protease inhibitors. Nelfinavir also has a role in the management of pregnant patients as well as paediatric patients with HIV infection.