Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection
Management of Medication Toxicity or Intolerance
Last Updated: April 27, 2017; Last Reviewed: April 27, 2017
|Rating of Recommendations: A = Strong; B = Moderate; C = Optional
Rating of Evidence: I = One or more randomized trials in children† with clinical outcomes and/or validated endpoints; I* = One or more randomized trials in adults with clinical outcomes and/or validated laboratory endpoints with accompanying data in children† from one or more well-designed, nonrandomized trials or observational cohort studies with long-term clinical outcomes; II = One or more well-designed, nonrandomized trials or observational cohort studies in children† with long-term outcomes; II* = One or more well-designed, nonrandomized trials or observational studies in adults with long-term clinical outcomes with accompanying data in children† from one or more similar nonrandomized trials or cohort studies with clinical outcome data; III = Expert opinion
† Studies that include children or children/adolescents but not studies limited to post-pubertal adolescents
Medication Toxicity or Intolerance
The overall benefits of viral suppression and improved immune function as a result of effective antiretroviral therapy (ART) far outweigh the risks associated with the adverse effects (AEs) of some antiretroviral (ARV) drugs. However, AEs have been reported with the use of all ARV drugs and—in the mid-1990s when combination ART was introduced—were among the most common reasons for switching or discontinuing therapy and for medication nonadherence (see Adult ARV Guidelines).1
Fortunately, currently recommended ARV regimens are associated with fewer serious and intolerable AEs than regimens used in the past. Generally, less than 10% of ART-naive patients enrolled in randomized trials have treatment-limiting AEs.2-12 Some longer-term complications of ART (e.g., bone or renal toxicity, dyslipidemia, or accelerated cardiovascular disease) may be underestimated because most clinical trials enroll a select group of patients based on highly specific inclusion criteria and the duration of participant follow-up is relatively short. To achieve sustained viral suppression over a child’s lifetime, both short-term and long-term ART toxicities must be anticipated. The clinician must consider potential AEs and issues with medication palatability when selecting an ARV regimen, as well as the individual child’s comorbidities, concomitant medications, and prior history of drug intolerance or viral resistance.
ARV drug-related AEs can vary from mild, more common symptoms (e.g., gastrointestinal intolerance, fatigue) to infrequent, but severe and life-threatening, illness. Drug-related toxicity can be acute (occurring soon after a drug has been administered), subacute (occurring within 1 to 2 days of administration), or late (occurring after prolonged drug administration). For a few ARV medications, pharmacogenetic markers associated with risk of early toxicity have been identified, but the only such screen in routine clinical use is HLA B*5701 as a marker for abacavir hypersensitivity.13-15 For selected children aged <3 years who require treatment with efavirenz, an additional pharmacogenetic marker, CYP2B6 genotype, should be assessed in an attempt to prevent toxicity (see Efavirenz in Appendix A: Pediatric Antiretroviral Drug Information).14-17 For agents such as efavirenz, therapeutic ranges for plasma concentrations as determined by therapeutic drug monitoring (TDM) may indicate the need for dose reduction or modification of ART in patients experiencing central nervous system (CNS) AEs (see below and Role of Therapeutic Drug Monitoring in Management of Pediatric HIV Infection).
The most common acute and chronic AEs associated with ARV drugs or drug classes are presented in the Management of Medication Toxicity or Intolerance tables. The tables include information on common causative drugs, estimated frequency of occurrence, timing of symptoms, risk factors, potential preventive measures, and suggested clinical management strategies and provide selected references regarding these toxicities in pediatric patients.
ART-associated AEs can range from acute and potentially life-threatening to chronic and insidious. Serious life-threatening events (e.g., hypersensitivity reaction due to abacavir, symptomatic hepatotoxicity, or severe cutaneous reactions) require the immediate discontinuation of all ARV drugs and reinitiation of an alternative regimen without overlapping toxicity. Toxicities that are not life-threatening (e.g., urolithiasis with atazanavir, renal tubulopathy with tenofovir disoproxil fumarate) can usually be managed by substituting another ARV agent for the presumed causative agent without interrupting ART. Other, chronic, non–life-threatening AEs (e.g., dyslipidemia) can be addressed either by switching the potentially causative agent for another agent or by managing the AE with additional pharmacological or nonpharmacological interventions.
Management strategies must be individualized for each child, taking into account severity of the toxicity, the relative need for further viral suppression, and the available ARV options. Common, self-limited AEs should be anticipated, and reassurance provided that many AEs will resolve after the first few weeks of ART. For example, when initiating therapy with boosted protease inhibitors (PIs), many patients experience gastrointestinal AEs such as nausea, vomiting, diarrhea, and abdominal pain. Instructing patients to take PIs with food may help minimize these AEs. Some patients may require antiemetics and antidiarrheal agents for symptom management. Central nervous system AEs are commonly encountered when initiating therapy with efavirenz. Symptoms can include dizziness, drowsiness, vivid dreams, or insomnia. Patients should be instructed to take efavirenz-containing regimens at bedtime, on an empty stomach, to help minimize these AEs. They should be advised that these AEs usually diminish in general within 2 to 4 weeks of initiating therapy in most people, but may persist for months in some, and may require a medication change.18-20 In addition, mild rash can be ameliorated with drugs such as antihistamines. For some moderate toxicities, using a drug in the same class as the one causing toxicity but with a different toxicity profile may be sufficient and discontinuation of all therapy may not be required.
In patients who experience unacceptable AEs from ART, every attempt should be made to identify the offending agent and to replace the drug with another effective agent as soon as possible.21,22 Many experts will stagger a planned interruption of a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen, stopping the NNRTI first and the dual nucleoside analogue reverse transcriptase backbone 7 to 14 days later because of the long half-life of NNRTI drugs. For patients who have a severe or life-threatening toxicity (e.g., hypersensitivity reaction—see Hypersensitivity Reaction, Table 13l), however, all components of the drug regimen should be stopped simultaneously, regardless of drug half-life. Once the offending drug or alternative cause for the AE has been determined, planning can begin for resumption of therapy with a new ARV regimen that does not contain the offending drug or with the original regimen, if the event is attributable to another cause. All drugs in the ARV regimen should then be started simultaneously, rather than one at a time with observation for AEs.
When therapy is changed because of toxicity or intolerance in a patient with virologic suppression, agents with different toxicity and side-effect profiles should be chosen, when possible.23-27 Clinicians should have comprehensive knowledge of the toxicity profile of each agent before selecting a new regimen. In the event of drug intolerance, changing a single drug in a multidrug regimen is permissible for patients whose viral loads are undetectable. However, substitution of a single active agent for a single drug in a failing multidrug regimen (e.g., a patient with virologic failure) is generally not recommended because of concern for development of resistance (see Recognizing and Managing Antiretroviral Treatment Failure in Management of Children Receiving Antiretroviral Therapy).
In general, dose-reduction is not a recommended strategy for the management of toxicity due to concern for decreased virologic efficacy with inadequate ARV drug levels. Although TDM is not routinely recommended, it may be used in the management of a child with mild or moderate toxicity if the toxicity is thought to be the result of a drug concentration exceeding the normal therapeutic range28,29 (see Role of Therapeutic Drug Monitoring). An expert in the management of pediatric HIV infection should be consulted when considering dose reduction based on the results of TDM. Dose-reduction after TDM has the most data for efavirenz, where increased CNS toxicity has clearly been associated with higher drug levels. (see Efavirenz in Appendix A: Pediatric Antiretroviral Drug Information)
To summarize, management strategies for drug intolerance include:
- Symptomatic treatment of mild-to-moderate transient AEs.
- Changing from one drug to another drug to which a patient’s virus is susceptible (such as changing to abacavir for zidovudine-related anemia or to a PI or integrase strand transfer inhibitor (INSTI) for efavirenz-related CNS symptoms).
- Changing drug classes (e.g., from a PI to an INSTI or a NNRTI or vice versa) if a patient’s virus is susceptible to a drug in that class.
- Using dose reduction as guided by TDM in consultation with an expert in pediatric HIV infection.
- Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. 2016. Available at http://aidsinfo.nih.gov/contentfiles/lvguidelines/AdultandAdolescentGL.pdf.
- Buck WC, Kabue MM, Kazembe PN, Kline MW. Discontinuation of standard first-line antiretroviral therapy in a cohort of 1434 Malawian children. J Int AIDS Soc. 2010;13:31. Available at http://www.ncbi.nlm.nih.gov/pubmed/20691049.
- Sauvageot D, Schaefer M, Olson D, Pujades-Rodriguez M, O'Brien DP. Antiretroviral therapy outcomes in resource-limited settings for HIV-infected children <5 years of age. Pediatrics. 2010;125(5):e1039-1047. Available at http://www.ncbi.nlm.nih.gov/pubmed/20385636.
- Tukei VJ, Asiimwe A, Maganda A, et al. Safety and tolerability of antiretroviral therapy among HIV-infected children and adolescents in Uganda. J Acquir Immune Defic Syndr. 2012;59(3):274-280. Available at http://www.ncbi.nlm.nih.gov/pubmed/22126740.
- Arpadi S, Shiau S, Strehlau R, et al. Metabolic abnormalities and body composition of HIV-infected children on Lopinavir or Nevirapine-based antiretroviral therapy. Arch Dis Child. 2013;98(4):258-264. Available at http://www.ncbi.nlm.nih.gov/pubmed/23220209.
- Arrow Trial team, Kekitiinwa A, Cook A, et al. Routine versus clinically driven laboratory monitoring and first-line antiretroviral therapy strategies in African children with HIV (ARROW): a 5-year open-label randomised factorial trial. Lancet. 2013;381(9875):1391-1403. Available at http://www.ncbi.nlm.nih.gov/pubmed/23473847.
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- Cohen S, Smit C, van Rossum AM, et al. Long-term response to combination antiretroviral therapy in HIV-infected children in the Netherlands registered from 1996 to 2012. AIDS. 2013;27(16):2567-2575. Available at http://www.ncbi.nlm.nih.gov/pubmed/23842124.
- Palmer M, Chersich M, Moultrie H, Kuhn L, Fairlie L, Meyers T. Frequency of stavudine substitution due to toxicity in children receiving antiretroviral treatment in sub-Saharan Africa. AIDS. 2013;27(5):781-785. Available at http://www.ncbi.nlm.nih.gov/pubmed/23169331.
- Prendergast AJ. Complications of long-term antiretroviral therapy in HIV-infected children. Arch Dis Child. 2013;98(4):245-246. Available at http://www.ncbi.nlm.nih.gov/pubmed/23413313.
- Purswani M, Patel K, Kopp JB, et al. Tenofovir treatment duration predicts proteinuria in a multiethnic United States Cohort of children and adolescents with perinatal HIV-1 infection. Pediatr Infect Dis J. 2013;32(5):495-500. Available at http://www.ncbi.nlm.nih.gov/pubmed/23249917.
- Shubber Z, Calmy A, Andrieux-Meyer I, et al. Adverse events associated with nevirapine and efavirenz-based first-line antiretroviral therapy: a systematic review and meta-analysis. AIDS. 2013;27(9):1403-1412. Available at http://www.ncbi.nlm.nih.gov/pubmed/23343913.
- Lubomirov R, Colombo S, di Iulio J, et al. Association of pharmacogenetic markers with premature discontinuation of first-line anti-HIV therapy: an observational cohort study. J Infect Dis. 2011;203(2):246-257. Available at http://www.ncbi.nlm.nih.gov/pubmed/21288825.
- Aceti A, Gianserra L, Lambiase L, Pennica A, Teti E. Pharmacogenetics as a tool to tailor antiretroviral therapy: A review. World J Virol. 2015;4(3):198-208. Available at http://www.ncbi.nlm.nih.gov/pubmed/26279982.
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- Sinxadi PZ, Leger PD, McIlleron HM, et al. Pharmacogenetics of plasma efavirenz exposure in HIV-infected adults and children in South Africa. Br J Clin Pharmacol. 2015;80(1):146-156. Available at http://www.ncbi.nlm.nih.gov/pubmed/25611810.
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