Names and pronunciation
(ah-bak′ah-veer) Ziagen
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Drug reference
(ah-bak′ah-veer) Ziagen
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Func. class.: Antiretroviral
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Chem. class.: Nucleoside reverse transcriptase inhibitor (NRTI)
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Do not confuse: abacavir/amprenavir
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ACTION: Inhibitory action against HIV-1; inhibits replication of the virus by incorporating into cellular DNA by viral reverse transcriptase, thereby termi- nating the cellular DNA chain
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USES: In combination with other anti- retroviral agents for HIV-1 infection
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Unlabeled uses: HIV prophylaxis fol- lowing occupational exposure
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CONTRAINDICATIONS
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Black Box Warning: Hypersensitivity, moderate/severe hepatic disease, lactic acidosis Precautions: Pregnancy, breastfeeding, children <3 mo, granulocyte count <1000/mm3 or HB <9.5 g/dL, severe renal disease, impaired hepatic function, HLA B5701+ (Black, White, Asian patients), abrupt discontinuation; Guillain- Barré syndrome, immune reconstitution syndrome, MI, obesity, polymyositis Black Box Warning: Lactic acidosis (elevated lactate levels, increased LFTs), severe hepatomegaly with steatosis, dis- continue and do not restart; may have enlarged liver, elevated AST, ALT, lactate levels; women and the obese may be at greater risk; monitor serum lactate levels, LFTs, palpate liver for enlargement Black Box Warning: Fatal hypersen- sitivity reactions: fever, rash, nausea, vomiting, fatigue, cough, dyspnea, diar- rhea, abdominal discomfort; treatment should be discontinued and not restarted; those with HLA-B5701 are at great risk for hypersensitivity; obtain testing for HLA-B 5701 prior to starting treatment, register at the Abacavir Hypersensitivity Registry (800-270-0425) • Renal studies: BUN; serum uric acid; CCr prior to, during therapy; these may be elevated Black Box Warning: Hepatotoxicity: monitor hepatic studies prior to and monthly during therapy: bilirubin, AST, ALT, amylase, alkaline phosphatase, creatine phosphokinase, creatinine • Blood counts: monitor viral load and CD4 counts during treatment; watch for decreasing granulocytes, HB; if low, ther- apy may have to be discontinued and re- started after recovery; blood transfusions may be required; perform hepatitis B vi- rus (HBr) screening to confirm correct treatment • Resistance: do not use triple antiret- rovirals (abacavir, lamivudine, tenofovir) in treatment-naive persons • Immune reconstitution syndrome: may occur anytime during treatment and is a response to CMV, Mycobacterium avium infection • Fat redistribution: may occur anytime during treatment; buffalo hump, breast growth, moon face, facial wasting, trunk obesity
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SIDE EFFECTS CNS: Fever, headache, malaise, insom nia, lethargy GI: Nausea, vomiting, diarrhea, anorexia, increase AST/ALT, hepatotoxicity, hepato- megaly with steatosis INTEG: Rash, urticaria, hypersensitivity reactions META: Lactic acidosis OTHER: Fatal hypersensitivity reactions, MI, fat redistribution, immune reconstitution
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INTERACTIONS • Do not coadminister with abacavir- containing products, ribavirin, interferon • Increase: possible lactic acidosis— ribavirin Increase: abacavir levels—alcohol Decrease: levels of methadone, may require higher dose of methadone Drug/Lab Test Increase: serum glucose, triglycerides, ALT, AST, amylase, CK
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DOSAGE AND ROUTES • Adult and adolescent ≥16 yr: PO 300 mg bid or 600 mg/day with other antiret- rovirals • Adolescent <16 yr and child ≥3 mo: PO (oral solution) 8 mg/kg bid or 16 mg/kg daily, max 300 mg bid with other antiretrovirals; tablets 14-19 kg 150 mg bid or 300 mg daily; 20-24 kg 150 mg AM and 300 mg PM or 450 mg daily; ≥25 kg 300 mg bid or 600 mg daily Hepatic dose • Adult: PO (Child-Pugh A [5-6 points]) (oral solution) 200 mg bid; moderate to severe hepatic disease, do not use HIV prophylaxis (unlabeled) A • Adult: PO 600 mg daily as an alternative
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Available forms: Tablets 300 mg; oral solution 20 mg/mL
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Administer: • Give in combination with other anti- retrovirals • May give without regard to food q12hr around the clock • Reduce dose in hepatic disease, use oral sol • Storage at room temperature; protect from light; oral solution stored at room temperature; do not freeze
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Assess: • Symptoms of HIV and possible infec- tions; increased temperature baseline and throughout treatment
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Evaluate: • Therapeutic response: increased CD4 count, decreased viral load, decreased disease progression
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • That product is not a cure but will control symptoms; that patient is still in- fective, may pass HIV virus on to others, not to have sexual contact without con- dom, needles should not be shared, blood from infected individual should not come in contact with another’s mu- cous membranes • To carry emergency ID with condition, products taken; not to take other prod- ucts that contain abacavir • That body fat redistribution may oc- cur; not to share product • Hypersensitivity: to notify prescriber of sore throat, swollen lymph nodes, malaise, fever; other infections may oc- cur; stop product and to notify pre- scriber immediately if skin rash, fever, cough, shortness of breath, GI symp- toms occur; to advise all health care providers that allergic reaction has oc- curred with abacavir • That follow-up visits must be contin- ued because serious toxicity may occur; blood counts must be done • To review and discuss points outlined on Medication Guide and Warning Card • That other products may be necessary to prevent other infections and that drug is taken with other antiretrovirals • Not to drink alcohol while taking this product • To use exactly as prescribed, not to stop product or change dose, not to use with other products unless approved by prescriber • Pregnancy/breastfeeding: to consider the use of contraception during treatment; identify if pregnancy is planned or sus- pected; use only if benefits outweigh risk; pregnant patients should enroll in Antiret- roviral Pregnancy Registry at 800-258- 4263; avoid breastfeeding
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PHARMACOKINETICS Rapid/extensive absorption, distributed to extravascular space, then erythrocytes; 50% protein binding; extensively metab- olized to inactive metabolites by the liver; half-life 1½ hr; excreted in urine, feces (unchanged); onset, peak, 1-1.5 hr, duration unknown
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• Adult and adolescent ≥16 yr: PO 300 mg bid or 600 mg/day with other antiret- rovirals
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• Adolescent <16 yr and child ≥3 mo: PO (oral solution) 8 mg/kg bid or 16 mg/kg daily, max 300 mg bid with other antiretrovirals; tablets 14-19 kg 150 mg bid or 300 mg daily; 20-24 kg 150 mg AM and 300 mg PM or 450 mg daily; ≥25 kg 300 mg bid or 600 mg daily Hepatic dose
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• Adult: PO (Child-Pugh A [5-6 points]) (oral solution) 200 mg bid; moderate to severe hepatic disease, do not use HIV prophylaxis (unlabeled) A
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• Adult: PO 600 mg daily as an alternative
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