abacavir uses and sied effects

 abacavir 

(ah-back-ah-veer) Ziagen

 Classification Therapeutic: antiretrovirals Pharmacologic: nucleoside reverse transcriptase inhibitors

 Pregnancy Category C

 Indications of abacavir

Management of HIV infection (AIDS) in combination with other antiretrovirals (not with lamivudine and/or tenofovir).

 Action  of abacavir

Converted inside cells to carbovir triphosphate, its active metabolite. Carbovir triphosphate inhibits the activity of HIV-1 reverse transcriptase, which in turn terminates viral DNA growth.

 Therapeutic Effects: Slows the progression of HIV infection and decreases the occurrence of its sequelae. Increases CD4 cell counts and decreases viral load.

 Pharmacokinetics  of abacavir

Absorption: Rapidly and extensively (83%) absorbed. Distribution: Distributes into extravascular space and readily distributes into erythrocytes.

 Metabolism and Excretion: Mostlymetabolized by the liver; 1.2% excreted unchanged in urine. Half-life: 1.5 hr. 

Contraindications/Precautions  of abacavir

Contraindicated in: 

Hypersensitivity (rechallenge may befatal); Lactation: Breast feeding not recommended for HIV-infected patients. 

Use Cautiously in: Coronary heart disease; 

OB: Safety not established; Pedi: Children 3 mo (safety not established). 

Exercise Extreme Caution in: Patients positive for HLA-B*5701 allele (unless exceptional circumstances exist where benefits clearly outweigh the risks). 

Adverse Reactions/Side Effects of abacavir

CNS: headache, insomnia.  

CV: MYOCARDIAL INFARCTION.

 GI: HEPATOMEGALY (WITH STEATOSIS), diarrhea , , anorexia. 

Derm: rashes. FandE: nausea , vomiting LACTIC ACIDOSIS. 

Misc: HYPERSENSITIVITY REACTIONS, fat redistribution, immune reconstitution syndrome. 

 Interactions Drug-Drug: of abacavir

Alcohol ^ bloodlevels. May increase methadonemetabolism in some patients; slight inctrease in methadone dosing may be needed. 

Route/Dosage of abacavir

 PO(Adults): 300 mg twice daily. 

PO(Children 3 mo–16yr):8mg/kg twicedaily (not to exceed 300 mg twice daily). 

Availability (generic available) 

Tablets: 300 mg. 

Oral solution (strawberry/banana flavor): 20mg/mL.

 In combination with: lamivudine (Epzicom); lamivudine and zidovudine (Trizivir). 

NURSING IMPLICATIONS of abacavir

Assessment

 ● Assess patient for change in severity of HIV symptoms and for symptoms of opportunistic infections throughout therapy. 

● Assess for signs of hypersensitivity reactions (fever; rash; gastrointestinal—nausea, vomiting, diarrhea, abdominal pain; constitutional—malaise, fatigue, achiness; respiratory—dyspnea, cough, pharyngitis). May also cause elevated liver function tests, increased creatine phosphokinase or creatinine, and lymphopenia. 

Discontinue promptly if hypersensitivity reaction is suspected. permanently discontinue abacavir if hypersensitivity cannot be ruled out, even when other diagnoses are possible. Following a hypersensitivity reaction, never restart abacavir or abacavir-containing products. More severe symptoms may occur within hours and may include life-threatening hypotension and death. 

Symptoms usually resolve upon discontinuation. 

● May cause lactic acidosis and severe hepatomegaly with steatosis. Monitor patient for signs (qserum lactate levels,qliver enzymes, liver enlargement on palpation). Therapy should be suspended if clinical or laboratory signs occur. 

● LabTestConsiderations: 

Monitor viral load and CD4 cell count regularly during therapy. 

● Screen for HLA-B*5701 allele prior to initiation of therapy to decrease risk of hypersensitivity reaction. Screening is also recommended prior to reinitiation of abacavir in patients of unknown HLAB*5701 status who have previously tolerated abacavir. 

● Monitor liver function. May cause increase levels of AST, ALT, and alkaline phosphatase, which usually resolve after interruption of therapy. Lactic acidosis

● May cause increase serum glucose and triglyceride levels. 

Potential Nursing Diagnoses 

Risk for infection (Indications) Noncompliance (Patient/Family Teaching) 

Implementation

 ● PO:Maybeadministered with or without food. Oral solution may be stored at room temperature or refrigerated; do not freeze. 

Tablet may be used with children if able to swallow and dose is correctly calculated. 

Patient/Family Teaching 

● Emphasize the importance of taking abacavir as directed. Must always be used in combination with other antiretroviral drugs. Do not take more than prescribed amount, and do not stop taking without consulting health care professional. Take missed doses as soon as remembered; do not double doses. Advise patient to read the Medication Guide prior to starting therapy and with each Rx refill in case of changes.

 ● Instruct patient not to share abacavir with others. 

● Inform patient that abacavir does not cure AIDS or prevent associated or opportunistic infections. Abacavir does not reduce the risk of transmission of HIV to others through sexual contact or blood contamination. Caution patient to use a condom, and avoid sharing needles or donating blood to prevent spreading the AIDS virus to others. Advise patient that the long-term effects of abacavir are unknown at this time. 

● Advise patient of potential for hypersensitivity reactions that may result in death. Instruct patient to discontinue abacavir and notify health care professional immediately if symptoms of hypersensitivity or signs of Immune Reconstitution Syndrome (signs and symptoms of an infection) occur. Advise patient to read Medication Guide thoroughly with each refill in case of changes. A warning card summarizing symptoms of abacavir hypersensitivity is provided with each prescription; instruct patient to carry card at all times.

 ● Instruct patient to notify health care professional immediately if symptoms of lactic acidosis (tiredness or weakness, unusual muscle pain, trouble breathing, stomach pain with nausea and vomiting, cold especially in arms or legs, dizziness, fast or irregular heartbeat) or if signs of hepatotoxicity (yellow skin or whites of eyes, dark urine, light-colored stools, lack of appetite for several days or longer, nausea, abdominal pain) occur. These symptoms may occur more frequently in patients that are female, obese, or have been taking medications like abacavir for a long time.