Tags: Lopinavir

Treatment of HIV / AIDS

The goal of antiretroviral therapy is to achieve the maximum suppression of HIV replication (HIV RNA level that is less than the lower limit of quantitation). Secondary goals include an increase in CD4 lymphocytes and an improved quality of life. The ultimate goal is decreased morbidity and mortality.

Antimicrobial Regimen Selection

A generally accepted systematic approach to the selection and evaluation of an antimicrobial regimen is shown in Table Systematic Approach for Selection of Antimicrobials. An «empiric» antimicrobial regimen is begun before the offending organism is identified, while a «definitive» regimen is instituted when the causative organism is known. The use of combinations to prevent the emergence of resistance is widely applied but not often realized. The only circumstance where this has been clearly effective is in the treatment of tuberculosis.

Antiretroviral Agents General Statement

Decisions regarding when to initiate or modify antiretroviral therapy should be guided by monitoring plasma HIV-1 RNA levels (viral load), CD4+ T-cell counts, and the clinical condition of the patient. Although various other surrogate markers and laboratory parameters were used in the past to assess the risk of progression of HIV infection and evaluate efficacy of antiretroviral agents.

Patient Compliance and Issues Related to Dosage and Administration

Patient compliance with recommended regimens (even when asymptomatic) is essential to the potential benefits of antiretroviral therapy. Adherence to antiretroviral regimens is an important determinant of both the degree and duration of virologic suppression. Excellent adherence has been shown to increase the likelihood of sustained virologic control, which is important for reducing HIV-associated morbidity and mortality. Poor adherence has been shown to increase the likelihood of virologic failure and can lead to the development of resistance and limit the effectiveness of antiretroviral therapy.

Drug Interactions Among the Antiretroviral Agents

While further study is needed, data are accumulating regarding pharmacokinetic interactions among the various antiretroviral agents, especially those involving the HIV protease inhibitors and NNRTIs, and the need for dosage adjustments as a result of these interactions. While some pharmacokinetic interactions between antiretroviral agents can be used for therapeutic advantage (e.g., use of low-dose ritonavir to boost plasma concentrations of some other HIV protease inhibitors), other interactions can result in suboptimal drug concentrations and reduced therapeutic effects and should be avoided. The pharmacokinetic interaction between ritonavir and other HIV protease inhibitors is now used for therapeutic advantage in various antiretroviral regimens.

HIV Protease Inhibitors

The fact that hyperglycemia, new-onset diabetes mellitus, exacerbation of preexisting diabetes mellitus, and diabetic ketoacidosis have occurred in HIV-infected individuals receiving HIV protease inhibitors should be considered when these drugs are used during pregnancy. Because pregnancy is itself a risk factor for hyperglycemia and it is not known whether use of an HIV protease inhibitor exacerbates this risk, glucose concentrations should be monitored closely in pregnant women receiving these drugs and these women should be advised about the warning signs of hyperglycemia and diabetes (e.g., increased thirst and hunger, unexplained weight loss, increased urination, fatigue, dry or itchy skin).

Antiretroviral Therapy during Pregnancy

Recommendations for use of antiretroviral agents for the treatment of HIV infection in pregnant HIV-infected women generally are the same as those for nonpregnant HIV-infected adults, and women should receive optimal antiretroviral therapy regardless of pregnancy status. Although zidovudine is the only antiretroviral agent currently labeled for use in pregnant women, most clinicians do not consider pregnancy a contraindication for multiple-drug antiretroviral therapy when such therapy is indicated, especially during the second or third trimester.

Antiretroviral Therapy in Pediatric Patients

The same general principles of antiretroviral therapy that apply to HIV-infected adults also apply to HIV-infected pediatric patients; however, the treatment of HIV-infected neonates, children, and adolescents involves unique pharmacologic, virologic, and immunologic considerations. In 1993, the Working Group on Antiretroviral Therapy and Medical Management of HIV-infected Children, a panel convened by the National Pediatric and Family HIV Resource Center (NPHRC), the Health Resources and Services Administration (HRSA), and the National Institutes of Health (NIH) first issued guidelines for the use of antiretroviral agents in the treatment of HIV-infected children. At that time, monotherapy with zidovudine or didanosine was considered an appropriate regimen for initial therapy in HIV-infected pediatric patients.

Antiretroviral Therapy in Previously Treated Adults

A review of the agents that the patient already has received is essential. Resistance testing (performed while the patient is still receiving the old regimen) is useful in maximizing the number of active drugs in the new regimen. Viral resistance is an important, but not the only, reason for treatment failure.

Asymptomatic HIV Infection

The optimal time to initiate antiretroviral therapy in asymptomatic patients is unclear. A decision to initiate antiretroviral therapy in an HIV-infected adult or adolescent who is asymptomatic should be made after considering the patient’s willingness to begin antiretroviral therapy.