The FDA has approved ibalizumab-uiyk (Trogarzo – Theratechnologies/TaiMed), a CD4-directed monoclonal antibody, for IV treatment of multidrug-resistant HIV-1 (MDR-HIV) infection in heavily antiretroviral-experienced adults with treatment failure on their current regimen. Ibalizumab-uiyk is the first biologic drug to be approved by the FDA for treatment of HIV-1 infection.

The FDA has approved Mavyret (Abbvie) and Vosevi (Gilead), two new fixed-dose combinations of direct-acting antiviral (DAA) drugs, for treatment of chronic hepatitis C virus (HCV) infection caused by any of the six major HCV genotypes in patients without cirrhosis or with compensated cirrhosis. Both are approved for use in treatment-experienced patients. Mavyret is also approved for treatment-naive patients.

The FDA has approved Odefsey (Gilead), a once-daily, fixed-dose combination of the non-nucleoside reverse transcriptase inhibitor (NNRTI) rilpivirine and the nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) emtricitabine and tenofovir alafenamide, for initial treatment of HIV-1 infection in patients with HIV-1 RNA (viral load) ≤100,000 copies/mL or to replace a stable antiretroviral regimen in patients who have been virologically suppressed (viral load <50 copies/mL) for at least six months with no history of treatment failure.

The FDA has approved elvitegravir (Vitekta – Gilead), an integrase strand transfer inhibitor (INSTI), for use with a protease inhibitor (PI) plus ritonavir and other antiretroviral drugs for treatment of HIV-1 infection in treatment-experienced adults. Elvitegravir is also available in a fixed-dose combination (Stribild) with the pharmacokinetic enhancer cobicistat and the nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) emtricitabine and tenofovir disoproxil fumarate (DF). A similar combination (Genvoya) that includes tenofovir alafenamide instead of tenofovir DF was recently approved by the FDA and will be reviewed in a future issue.

The FDA has approved Triumeq (Viiv Healthcare), a fixed-dose combination of the integrase strand transfer inhibitor (INSTI) dolutegravir and the nucleoside reverse transcriptase inhibitors (NRTIs) abacavir and lamivudine, for once-daily treatment of HIV-1 infection. Dolutegravir (Tivicay) was approved as a single agent in 2013.

The FDA has approved a fixed-dose combination (Harvoni [har voe' nee] – Gilead) of sofosbuvir and ledipasvir (led' i pas' vir), two oral direct-acting antiviral agents, for treatment of chronic hepatitis C virus (HCV) genotype 1 infection. Genotype 1 is responsible for 70-80% of HCV infections in the US. Sofosbuvir (Sovaldi) was approved earlier for use in combination with other antiviral drugs for treatment of HCV infection. Ledipasvir is a new drug.

The FDA has approved the nucleotide polymerase inhibitor sofosbuvir (Sovaldi – Gilead) for use in combination with other antiviral drugs for treatment of chronic hepatitis C virus (HCV) infection.

The FDA has recently approved 2 new drugs for treatment of chronic hepatitis C virus (HCV) infection. Simeprevir (Olysio – Janssen) is the third oral protease inhibitor to be approved for use in combination with peginterferon and ribavirin for treatment of chronic HCV genotype 1 infection in adults with compensated liver disease. Telaprevir (Incivek) and boceprevir (Victrelis) were approved in 2011 for the same indication. Sofosbuvir (Sovaldi – Gilead), a nucleotide analog polymerase inhibitor that has been approved for use with and without interferon for treatment of multiple HCV genotypes, will be reviewed in the next issue of The Medical Letter.

The FDA has approved dolutegravir (doll-you-TEG-rah-veer; Tivicay – Viiv Healthcare), an integrase strand transfer inhibitor (INSTI), for treatment of HIV-1 infection in adults and in children ≥12 years old who weigh at least 40 kg. It is the third INSTI to be approved by the FDA; raltegravir and elvitegravir were approved earlier.

Tuberculosis (TB) is still a common cause of death worldwide, and the prevalence of drug-resistant TB poses challenges to its treatment and control. Guidelines with detailed management recommendations are available from the American Thoracic Society, Centers for Disease Control and Prevention (CDC) and Infectious Diseases Society of America (IDSA).

The FDA has announced changes in the labeling of simvastatin to reduce the risk of myopathy. These changes include limiting the use of the 80-mg maximum dose to patients who have been taking it for 12 months or more without evidence of myopathy and new recommendations for use of simvastatin with other drugs. Simvastatin is available alone (Zocor, and others) and in combination with ezetimibe (Vytorin) and with niacin (Simcor).

Guidelines for use of antiretroviral agents continue to shift toward earlier and more continuous treatment, both to treat the patient and to prevent transmission of the disease to others. Resistance testing is now recommended when antiretroviral drugs are started. Increases in HIV RNA levels ("viral load") while on therapy may indicate development of drug resistance, requiring further testing and a change in the treatment regimen. Antiretroviral drugs interact with each other and with many other drugs; complete information on these interactions is available at www.aidsinfo.nih.gov.

Even though the incidence continues to decline in the United States, tuberculosis (TB) is still a common cause of death worldwide, and the prevalence of drug-resistant TB poses severe challenges to its treatment and control. Guidelines with detailed management recommendations are available from the Centers for Disease Control and Prevention (CDC), American Thoracic Society and Infectious Diseases Society of America (IDSA).

New guidelines for use of antiretroviral agents have been published, with a shift towards earlier and more continuous treatment. HIV infection is treated with combinations of antiretroviral drugs depending on the patientÆs HIV RNA levels ("viral load") and CD4 cell count. Increases in viral load while on therapy may indicate development of drug resistance, requiring further testing and a change in treatment regimen. Resistance testing is now recommended when a patient is first seen, regardless of when therapy will be started.

Etravirine (Intelence - Tibotec), a new non-nucleoside reverse transcriptase inhibitor (NNRTI), has received fast-track FDA approval for use in combination therapy in treatment-experienced adults who have HIV-1 infection resistant to an NNRTI and other antiretroviral agents.

Advertisements for atorvastatin (Lipitor), the market leader facing generic competition, have been in the news recently in the US. Lovastatin, pravastatin and simvastatin are all available generically at a much lower retail price or lower co-pay than atorvastatin.

The drugs of choice for treatment of some fungal infections are listed in the tables. Some of the indications and dosages recommended here have not been approved by the FDA. Other guidelines are available from the Infectious Diseases Society of America (www.idsociety.org).

The approval of new drugs and continuing concerns about drug toxicity and resistance have prompted new antiretroviral treatment guidelines. Resistance testing is not recommended before starting antiretroviral therapy. HIV infection is treated with combinations of antiretroviral drugs while monitoring the patient's HIV RNA levels ("viral load") and CD4 cell count. Increases in viral load while on therapy may indicate development of drug resistance requiring further testing and a change in treatment regimen.

Darunavir (Prezista - Tibotec), a new protease inhibitor, has received accelerated approval from the FDA for use in combination therapy of human-immunodeficiency virus (HIV) infection in previously treated adults. It is coadministered with low-dose ritonavir (Norvir), which increases its bioavailability.

Tipranavir (Aptivus - Boehringer Ingelheim), a new protease inhibitor, has received accelerated approval from the FDA. It must be given with ritonavir (Norvir). The combination is indicated for use with other antiretrovirals to treat HIV infection in highly treatment-experienced adults who have ongoing viral replication or in those with HIV strains known to be resistant to multiple protease inhibitors.

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.

New guidelines from The National Cholesterol Education Program recommend, as a therapeutic option, lowering treatment goals for LDL cholesterol (LDL-C) from <100 mg/dL to <70 mg/dL for patients at very high risk for coronary heart disease and from 130 mg/dL to <100 mg/dL for those at moderately high risk. A likely consequence of these recommendations is increased use of statins and use of higher doses with a concomitant increase in adverse effects.

New drug approvals as well as continuing concerns about drug toxicity and the development of resistance have prompted new antiretroviral treatment guidelines (Panel on Clinical Practices for Treatment of HIV Infection, November 10, 2003, www.aidsinfo.nih.gov).

Atazanavir (Reyataz - Bristol-Myers Squibb), a new protease inhibitor (PI), and emtricitabine (Emtriva - Gilead), a nucleoside analogue reverse transcriptase inhibitor (NRTI) chemically similar to lamivudine, have been approved by the FDA for treatment of HIV-1 infection. Both are taken once daily, unlike most anti-HIV drugs.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

The FDA has approved the marketing of buprenorphine in sublingual tablets (Reckitt Benckiser) both alone (Subutex) and with naloxone (Suboxone) for treatment of opioid dependence. Previously available only for parenteral use in treatment of pain (Buprenex, and others), it offers an alternative to methadone (Dolophine, and others), which is now often abused (New York Times, February 9, 2003; page 1). As a schedule III narcotic, buprenorphine will be subject to fewer prescribing restrictions than a schedule II drug such as methadone (MJ Kreek and FJ Vocci, J Subst Abuse Treat 2002; 23:93).w1150a

Since the last Medical Letter article on this subject, continuing concerns about drug toxicity and development of resistance have prompted new antiretroviral treatment guidelines. The dosage and cost of drugs for HIV infection are listed in the table in this article.

Highly active anti-retroviral therapy (HAART) combining three or four drugs has become the standard of care for treatment of human immunodeficiency virus (HIV) infection

Amprenavir is the fifth protease inhibitor to become available for treatment of HIV infection. It was approved by the FDA for use with other drugs in the treatment of HIV-infected adults and children at least four years old.

Reports of adverse interactions between drugs continue to accumulate. Recently, the FDA has expanded the recommendations on drug interactions found in the package inserts of new drugs.

Combination antiretroviral therapy including protease inhibitors has dramatically changed the treatment of HIV infection and the prognosis of those affected (Medical Letter Handbook of Antimicrobial Therapy, 1998, page 122). Due to limitations and failures with these drugs in many patients, however, three new drugs, none of them protease inhibitors, have rapidly come into wide use in clinical trials or 'expanded access' programs. They are abacavir (Ziagen - Glaxo Wellcome), adefovir (Preveon - Gilead) and efavirenz (Sustiva - DuPont). Efavirenz was recently approved for treatment of adults and children by the FDA. Abacavir has been recommended for approval by an FDA advisory committee.

Recent studies have led to changes in the approach to treating human immunodeficiency virus (HIV) infection (CCJ Carpenter et al, JAMA, 277:1962, 1997). None of the drugs currently available to treat HIV-infected patients has been shown to eradicate the infection, but used in combination they can decrease viral replication, improve immunologic status, delay infectious complications and prolong life. The drug regimens recommended by Medical Letter consultants are listed in the table on page 114. Adult regimens and dosages may not be applicable to children (Guidelines for use of Antiretroviral Agents in Pediatric HIV Infection, HIV/AIDS Treatment Information Services, www.hivatis.org/glarvped.html). Some drugs interactions of anti-HIV drugs are listed on the table that begins on page 115.

Four new drugs have become available in the USA for HIV infection or its complications. Nevirapine (Viramune - Roxane), intravenous cidofovir (Vistide - Gilead), and amphotericin B oral suspension (Fungizone Oral Suspension - Bristol-Myers Squibb) have been approved by the US Food and Drug Administration; nelfinavir (Viracept - Agouron) is currently available only through an "Expanded Access Program."

The US Food and Drug Administration (FDA) has approved the marketing of five new drugs for treatment of HIV Infection. Stavudine (D4T; Zerit - Bristol-Myers Squibb) and lamivudine (3TC; Epivir - Glaxo Wellcome) are nucleoside analogs similar to zidovudine (AZT), didanosine (ddl) and zalcitabine (ddC). Saquinavir (Invirase - Roche), ritonavir (Norvir - Abbott) and indinavir (Crixivan - Merck) are protease inhibitors, a new class of anti-HIV drugs.

Results of recently completed clinical trials have led to some changes in recommendation for treatment of human immunodeficiency virus (HIV) and other infections associated with AIDS.