Thursday, October 20, 2016

Lamivudine


Class: Nucleoside and Nucleotide Reverse Transcriptase Inhibitors
VA Class: AM800
Chemical Name: (2R-cis) 4-Amino-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-2(1H)-pyr imidinone
Molecular Formula: C8H11N3O3S
CAS Number: 134678-17-4
Brands: Combivir, Epivir, Epivir-HBV, Epzicom, Trizivir


Special Alerts:


[Posted 03/01/2011] ISSUE: FDA updated the public about an ongoing safety review of abacavir and a possible increased risk of heart attack. There has been conflicting information on the potential increased risk of heart attack with abacavir (Ziagen) treatment. An increased risk of heart attack (myocardial infarction or MI) has been seen in several observational studies and one randomized controlled trial (RCT) with abacavir. However, an increased risk of heart attack has not been seen in other RCTs and the safety database maintained by the drug manufacturer.


FDA conducted a meta-analysis of 26 randomized clinical trials that evaluated abacavir. This meta-analysis did not show an increased risk of MI associated with the use of abacavir. FDA will continue to communicate any new safety information to the public as it becomes available.


BACKGROUND: Abacavir is an antiviral medication used in combination with other antiretroviral drugs [abacavir and lamivudine (Epzicom); abacavir, lamivudine, and zidovudine (Trizivir)] for the treatment of HIV-1 infection.


RECOMMENDATION: Healthcare professionals should continue to prescribe abacavir according to the professional label. Patients should not stop taking their abacavir without first talking to their healthcare professional. For more information visit the FDA website at: and .





  • Lactic acidosis and severe hepatomegaly with steatosis (including some fatalities) reported rarely in patients receiving nucleoside reverse transcriptase inhibitors (NRTIs) alone or in conjunction with other antiretrovirals.1 18 (See Lactic Acidosis and Severe Hepatomegaly with Steatosis under Cautions.)




  • Epivir tablets and oral solution (used to treat HIV infection) contain a higher dose of lamivudine than Epivir-HBV tablets and oral solution (used to treat hepatitis B virus).1 Patients with HIV should receive only the dosage forms appropriate for treatment of HIV.1




  • HIV counseling and testing should be offered to all patients prior to and during Epivir-HBV therapy.18 Epivir-HBV tablets and oral solution contain a lower dose of lamivudine than Epivir tablets and oral solution.18 Use of Epivir-HBV in patients with unrecognized or untreated HIV infection may result in rapid emergence of resistant HIV because the dose is subtherapeutic and monotherapy is inappropriate.18




  • Severe acute exacerbations of hepatitis B virus (HBV) reported following discontinuance of lamivudine in patients coinfected with HBV and HIV.1 18 Monitor hepatic function closely with both clinical and laboratory follow-up for at least several months after lamivudine is discontinued in patients coinfected with HBV and HIV.1 18 If appropriate, initiation of treatment for HBV infection may be warranted.1 18




  • The fixed-combination preparation Combivir contains 2 NRTIs (lamivudine and zidovudine) the fixed-combination preparation Epzicom contains 2 NRTIs (lamivudine and abacavir), and the fixed-combination preparation Trizivir contains 3 NRTIs (abacavir, lamivudine, zidovudine); these are intended only for patients whose regimen would otherwise include lamivudine and the other components.37 60 104




  • If using Combivir or Trizivir, consider that zidovudine has been associated with hematologic toxicity including neutropenia and severe anemia, particularly in those with advanced HIV infection;60 66 and that prolonged zidovudine use has been associated with symptomatic myopathy.60 66




  • If using Trizivir, consider that data are limited regarding use of the fixed combination in patients with higher viral loads (>100,000 copies/mL) at baseline.37




  • If using Epzicom or Trizivir, consider that abacavir has been associated with serious and sometimes fatal hypersensitivity reactions.37 104




Introduction

Antiretroviral with antiviral activity against hepatitis B virus (HBV); nucleoside reverse transcriptase inhibitor (NRTI).1 4 9


Uses for Lamivudine


Treatment of HIV


Treatment of HIV infection in conjunction with other antiretrovirals.1 4 6 9 14 37 60


An alternative NRTI for use in multiple-drug antiretroviral regimens for initial therapy in adults.62


Fixed-combination preparation containing lamivudine and zidovudine (Combivir) used in conjunction with other antiretrovirals.60


Fixed-combination preparation containing lamivudine and abacavir (Epzicom) used in conjunction with other antiretrovirals.104


Fixed-combination preparation containing abacavir, lamivudine, and zidovudine (Trizivir) used for triple NRTI treatment;37 can be used alone or in conjunction with other antiretrovirals.37 If using Trizivir, consider that data are limited regarding use of the fixed combination in patients with higher viral loads (>100,000 copies/mL) at baseline.37


Because of a high rate of virologic failure, a triple NRTI regimen of abacavir, lamivudine, and tenofovir not recommended in treatment-naive or previously treated patients.62 103


Because of inferior antiretroviral activity, a triple NRTI regimen of abacavir, lamivudine, and zidovudine is not recommended for initial therapy.62


For patients coinfected with hepatitis B virus (HBV), some experts recommend an NRTI combination of tenofovir and (emtricitabine or lamivudine); avoid use of regimens containing only 1 of these antiretrovirals (may increase risk of HBV resistance).62 64


Maternal-fetal Transmission of HIV


If a single-dose nevirapine regimen (in conjunction with intrapartum/newborn zidovudine) is used for prevention of maternal-fetal transmission of HIV in women in labor who received no prior antiretroviral therapy, some clinicians suggest that consideration be given to adding lamivudine in the mother to reduce the development of nevirapine resistance.92


Postexposure Prophylaxis of HIV


Postexposure prophylaxis of HIV infection in health-care workers and others exposed occupationally via percutaneous injury or mucous membrane or nonintact skin contact with blood, tissues, or other body fluids associated with risk for transmission of the virus.54 Used in conjunction with other antiretrovirals.54


Postexposure prophylaxis of HIV infection in individuals who have had nonoccupational exposure to blood, genital secretions, or other potentially infectious body fluids of a person known to be infected with HIV when that exposure represents a substantial risk for HIV transmission.105 Used in conjunction with other antiretrovirals.105


Chronic Hepatitis B Virus (HBV) Infection


Management of chronic HBV infection associated with evidence of HBV replication and active liver inflammation.18 65 67 68 69 70 71 72 73 74 75


Safety and efficacy not established in patients with decompensated liver disease and there are no studies in pregnant women and no data regarding effect on vertical transmission of HBV.1


Safety and efficacy for treatment of chronic HBV infection in patients coinfected with both HBV and HIV have not been established.1


Patients coinfected with both HBV and HIV who require treatment for HBV and who are not receiving antiretroviral therapy should receive an antiviral agent for HBV infection that does not have activity against HIV.108


Appears to reduce risk of HBV reinfection in orthotopic liver transplant recipients.72 73 74


Treatment of chronic HBV infection is complex and rapidly evolving and should be directed by clinicians familiar with the disease; consult a specialist to obtain the most up-to-date information.107 k


Lamivudine Dosage and Administration


Administration


Oral Administration


Administer single-entity preparations (Epivir, Epivir-HBV) or fixed-combination preparations (Combivir, Epzicom, Trizivir) orally without regard to meals.1 18 37 60 62 104


For treatment of HIV infection, lamivudine oral solution containing 10 mg/mL and scored film-coated tablets containing 150 mg or 300 mg of the drug (Epivir) are used.1 Children who weigh ≥14 kg and who can swallow tablets may receive tablets.1


For management of chronic HBV infection, lamivudine oral solution containing 5 mg/mL and film-coated tablets containing 100 mg of the drug (Epivir-HBV) are used.18


Because dosage of lamivudine and zidovudine cannot be adjusted individually, the fixed-combination containing lamivudine and zidovudine (Combivir) should not be used in individuals requiring dosage adjustment, including children <12 years of age, patients with impaired renal function (i.e., Clcr <50 mL/minute), patients with impaired hepatic function, and patients who experience dose-limiting adverse effects.60


Since dosage of lamivudine and abacavir cannot be adjusted individually, the fixed-combination containing lamivudine and abacavir (Epzicom) should not be used in pediatric patients; patients with impaired renal function (i.e., Clcr <50 mL/minute); patients with hepatic impairment; or patients who experience dose-limiting adverse effects.104


Since dosage of the drugs cannot be adjusted individually, the fixed-combination containing lamivudine, abacavir, and zidovudine (Trizivir) should not be used in pediatric patients; adolescents or adults with low body weight (i.e., <40 kg); patients with impaired renal function (i.e., Clcr <50 mL/minute); patients with impaired hepatic function; or patients who experience dose-limiting adverse effects.37


Dosage


Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.


Dosage of Combivir, Epzicom, and Trizivir expressed as number of tablets.37 60 62 104


Epivir, Epzicom, and Combivir must be used in conjunction with other antiretrovirals;1 60 104 Trizivir may be used alone or in conjunction with other antiretrovirals.37


Pediatric Patients


Treatment of HIV Infection

Oral

Infants <30 days of age: 2 mg/kg twice daily (Epivir) suggested by some experts.77


Children 3 months to 16 years of age: Oral solution: 4 mg/kg (maximum 150 mg) twice daily (Epivir).1















Children who weigh ≥14 kg: Dosage recommendations for tablets (Epivir)1

Weight (kg)



AM dose



PM dose



14–21



75 mg



75 mg



>21 to <30



75 mg



150 mg



≥30



150 mg



150 mg


Adolescents ≥16 years of age weighing ≥50 kg: 150 mg twice daily or 300 mg once daily (Epivir).77


Adolescents ≥16 years of age weighing <50 kg: 4 mg/kg (maximum 150 mg) twice daily (Epivir).77


Combivir: 1 tablet twice daily in adolescents ≥12 years of age.60 77


Trizivir: 1 tablet twice daily in adolescents weighing ≥40 kg.37 77


Chronic Hepatitis B Virus (HBV) Infection

Oral

Children 2–17 years of age: 3 mg/kg once daily (maximum 100 mg) (Epivir-HBV).18


Optimal duration of treatment unknown; safety and efficacy >1 year not established.18


Adults


Treatment of HIV Infection

Oral

150 mg twice daily or 300 mg once daily (Epivir).1 62


Combivir: 1 tablet twice daily.60 62


Epzicom: 1 tablet once daily.104 62


Trizivir: 1 tablet twice daily37 62 in adults weighing ≥40 kg.37


Maternal-fetal Transmission of HIV

Zidovudine and Lamivudine Regimen

Oral

Women in labor who have received no prior antiretroviral therapy: 150 mg at onset of labor, then 150 mg every 12 hours during labor.92 Given with IV zidovudine during labor, then lamivudine 150 mg twice daily and oral zidovudine 300 mg twice daily for 1 week.92


Postexposure Prophylaxis of HIV

Occupational Exposure

Oral

300 mg once daily or 150 mg twice daily (Epivir).54


Initiate postexposure prophylaxis as soon as possible following exposure (within hours rather than days) and continue for 4 weeks, if tolerated.54


Nonoccupational Exposure

Oral

300 mg once daily or 150 mg twice daily (Epivir).105


Initiate postexposure prophylaxis as soon as possible following exposure (preferably ≤72 hours after exposure) and continue for 28 days.105


Chronic Hepatitis B Virus (HBV) Infection

Oral

100 mg once daily (Epivir-HBV).18


Optimal duration of treatment unknown; safety and efficacy >1 year not established.18


Prescribing Limits


Pediatric Patients


Treatment of HIV Infection

Oral

Children 3 months to 16 years of age: Maximum 150 mg twice daily (Epivir).1


Chronic Hepatitis B Virus (HBV) Infection

Oral

Children 2–17 years of age: Maximum 100 mg daily (Epivir-HBV).18


Special Populations


Hepatic Impairment


Treatment of HIV Infection

Oral

Dosage adjustment not needed.1


Chronic Hepatitis B Virus (HBV) Infection

Oral

Dosage adjustment not needed.18


Renal Impairment


Treatment of HIV Infection

Oral

Consider reducing dose and/or increasing dosing interval in pediatric patients with renal impairment; data insufficient to make a specific recommendation.1



















Dosage in Adults and Adolescents with Renal Impairment (Epivir).1

Clcr (mL/minute)



Dosage



≥50



150 mg twice daily or 300 mg once daily



30–49



150 mg once daily



15–29



150 mg first dose, then 100 mg once daily



5–14



150 mg first dose, then 50 mg once daily



<5



50 mg first dose, then 25 mg once daily



Hemodialysis Patients



Supplemental doses not necessary with routine (4-hour) hemodialysis



Peritoneal Dialysis Patients



Supplemental doses not necessary after peritoneal dialysis


Chronic Hepatitis B Virus (HBV) Infection

Oral

Consider reducing dose in pediatric patients with renal impairment; data insufficient to make a specific recommendation.18



















Dosage in Adults with Renal Impairment (Epivir-HBV).18

Clcr (mL/minute)



Dosage



≥50



100 mg once daily



30–49



100 mg first dose, then 50 mg once daily



15–29



100 mg first dose, then 25 mg once daily



5–14



35 mg first dose, then 15 mg once daily



<5



35 mg first dose, then 10 mg once daily



Hemodialysis Patients



Supplemental doses not necessary with routine (4-hour) hemodialysis



Peritoneal Dialysis Patients



Supplemental doses not necessary after peritoneal dialysis


Geriatric Patients


Select dosage with caution because of age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy.1


Cautions for Lamivudine


Contraindications



  • Known hypersensitivity to lamivudine or any ingredient in the formulation.1 18



Warnings/Precautions


Warnings


Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.


Lactic Acidosis and Severe Hepatomegaly with Steatosis

Lactic acidosis and severe hepatomegaly with steatosis (sometimes fatal) reported in patients receiving lamivudine.1 18 Reported most frequently in women; obesity and long-term NRTI therapy also may be risk factors.1 Has been reported in patients with no known risk factors.1 18


Use with caution in patients with known risk factors for liver disease.1 18


Interrupt therapy if there are clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (e.g., hepatomegaly and steatosis even in the absence of marked increases in serum aminotransferase concentrations).1 18


Considerations in Patients with Chronic Hepatitis B Virus (HBV) Infection

Posttreatment exacerbations of HBV infection and emergence of resistant strains of HBV reported following discontinuance of lamivudine therapy for HBV (non-HIV-infected patients).1 18 31 41 60 Exacerbations of HBV infection also reported following discontinuance of a lamivudine-containing antiretroviral regimen in patients coinfected with HBV and HIV.18


Clinical and laboratory evidence of exacerbations of hepatitis (increases in serum ALT concentrations, increases in serum HBV DNA levels) reported following discontinuance of lamivudine.18 Most events appear to have been self-limited; some fatalities reported.18


Closely monitor patients with both clinical and laboratory follow-up for at least several months after stopping lamivudine treatment.18 Insufficient evidence to determine whether reinitiation of therapy alters the course of posttreatment exacerbations of hepatitis.18


HIV counseling and testing should be offered to all patients prior to and during Epivir-HBV therapy.18


Epivir-HBV is not appropriate for patients coinfected with HBV and HIV since it contains a lower dose of lamivudine than Epivir.1 18 If a decision is made to use lamivudine in such patients, Epivir should be used in dosages appropriate for treatment of HIV infection.1 18 Use of Epivir-HBV in patients with unrecognized or untreated HIV infection may result in rapid emergence of resistant HIV because the dose is subtherapeutic and monotherapy is inappropriate.18


Interactions

Concomitant use with ribavirin and interferon alfa associated with increased risk of fatal hepatic decompensation in patients coinfected with HBV and HIV.1 i (See Specific Drugs under Interactions.)


General Precautions


Do not use multiple lamivudine-containing preparations concomitantly.1 18


Lamivudine should not be administered with emtricitabine (Emtriva) or fixed-combination preparations containing emtricitabine (Truvada, Atripla).62 a


Use of Fixed Combinations

When used in fixed combination with abacavir (Epzicom), consider the cautions, precautions, and contraindications associated with abacavir.104


When used in fixed combination with zidovudine (Combivir), consider the cautions, precautions, and contraindications associated with zidovudine.60


When used in fixed combination with abacavir and zidovudine (Trizivir), consider the cautions, precautions, and contraindications associated with the concomitant agents.37


HBV Resistance

Lamivudine-resistant HBV detected in patients receiving the drug for treatment of HBV; diminished treatment response reported.1 18 Lamivudine-resistant HBV also detected in HIV-infected patients coinfected with HBV who received a lamivudine-containing antiretroviral regimen.1 18


Monitoring ALT concentrations and HBV DNA levels may assist in treatment decisions if emergence of resistant HBV is suspected.18


Adipogenic Effects

Possible redistribution or accumulation of body fat, including central obesity, dorsocervical fat enlargement (“buffalo hump”), peripheral wasting, breast enlargement, and general cushingoid appearance.1


Immune Reconstitution Syndrome

During initial treatment, patients who respond to antiretroviral therapy may develop an inflammatory response to indolent or residual opportunistic infections (e.g., Mycobacterium avium complex [MAC], M. tuberculosis, cytomegalovirus [CMV], Pneumocystis jiroveci [formerly P. carinii]); this may necessitate further evaluation and treatment.1


Diabetes Mellitus

Epivir oral solution contains 3 g of sucrose per 15 mL of solution.1


Epivir-HBV oral solution contains 4 g of sucrose per 20 mL of solution.18


Possible Prescribing and Dispensing Errors

Ensure accuracy of the prescription; similarity of spelling lamotrigine (Lamictal) and lamivudine may result in errors.102


Specific Populations


Pregnancy

Category C.1 18


Antiretroviral Pregnancy Registry at 800-258-4263.1 18


A preferred NRTI for use in multiple-drug antiretroviral regimens in pregnant women.92


Lamivudine has not been shown to affect transmission of HBV from mother to infant; immunize the infant to prevent neonatal acquisition of HBV.18


Lactation

Distributed into human milk.1 18


Instruct HIV-infected women not to breast-feed because of risk of HIV transmission and risk of adverse effects in the infant.1


Instruct HBV-infected women not to breast-feed because of the risks of adverse effects in the infant.18


Pediatric Use

Safety and efficacy established for treatment of HIV infection in pediatric patients >3 months of age.1


Limited pharmacokinetic and safety data available in infants ≤1 week of age who received lamivudine for prevention of perinatal transmission of HIV.1


Pancreatitis, sometimes fatal, reported in antiretroviral nucleoside-experienced HIV-infected pediatric patients.1 Caution in pediatric patients with prior antiretroviral nucleoside exposure, history of pancreatitis, or other risk factors for pancreatitis.1 18 Discontinue lamivudine if sign, symptoms, or laboratory abnormalities suggestive of pancreatitis occur.1


Safety and efficacy established for management of chronic HBV infection in pediatric patients 2–17 years of age.18 Safety and efficacy for this indication not established in children <2 years of age.18


Geriatric Use

Insufficient experience in those ≥65 years of age to determine whether they respond differently than younger adults.1 18


Select dosage with caution because of age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy.1 18


Substantially eliminated by the kidneys; geriatric patients more likely to have decreased renal function; monitor renal function and adjust dosage accordingly.1 18


Hepatic Impairment

Safety and efficacy not established in the presence of decompensated liver disease.1 18


Use with caution in patients with known risk factors for liver disease.1 18


Renal Impairment

Dosage adjustment needed based on degree of renal impairment.1 18 (See Renal Impairment under Dosage and Administration.)


Common Adverse Effects


Nausea, fatigue and/or malaise, headache, nasal symptoms, diarrhea, cough.1


Interactions for Lamivudine


Eliminated in the urine by active organic cationic secretion; possibility of interactions with other drugs eliminated by active renal secretion via the organic cationic transport system.1 18


Specific Drugs













































Drug



Interaction



Comments



Abacavir



No clinically important pharmacokinetic interactions37


In vitro evidence of additive or synergistic antiretroviral effects1 14 79



Atazanavir



In vitro evidence of additive antiretroviral effects1



Co-trimoxazole



Increased lamivudine AUC; no change in pharmacokinetics of trimethoprim or sulfamethoxazole1 18



No dosage adjustment needed1 18



Emtricitabine



In vitro evidence of additive or synergistic antiretroviral effects; considered minimal62



Do not use concomitantly;62 no potential benefit since emtricitabine is an analog of lamivudine and has the same resistance profile62



Fosamprenavir



Studies using amprenavir indicate no evidence of pharmacokinetic interactiong



Interferon (interferon alfa, peginterferon alfa)



Possible increased risk of potentially fatal hepatic decompensation in patients coinfected with HCV and HIV who are receiving interferon alfa, ribavirin, and antiretroviral agents1 i



If lamivudine used in patients receiving interferon alfa or peginterferon alfa (with or without ribavirin), closely monitor for toxicities, especially hepatic decompensation; consider discontinuing lamivudine as appropriate; if worsening toxicities (e.g., hepatic decompensation Child-Pugh >6) are observed, consider discontinuing or reducing dosage of interferon and/or ribavirin1 i



Nelfinavir



In vitro evidence of additive or synergistic antiretroviral effects6 14 80



Ribavirin



Ribavirin can reduce phosphorylation of lamivudine; no evidence of pharmacokinetic or pharmacodynamic interaction in patients coinfected with HBV and HIV1 i


Possible increased risk of potentially fatal hepatic decompensation in patients coinfected with HCV and HIV who are receiving interferon alfa or peginterferon alfa, ribavirin, and antiretroviral agents1 i



If lamivudine used in patients receiving interferon alfa or peginterferon alfa (with or without ribavirin), closely monitor for toxicities, especially hepatic decompensation; consider discontinuing lamivudine as appropriate; if worsening toxicities (e.g., hepatic decompensation Childs Pugh >6) are observed, consider discontinuing or reducing dosage of interferon and/or ribavirin1 i



Saquinavir



In vitro evidence of additive or synergistic antiretroviral effects6 14 80



Stavudine



In vitro evidence of additive or synergistic antiretroviral effects1 14 79



Tenofovir



Pharmacokinetic interactions not clinically importantf


In vitro evidence of additive or synergistic antiretroviral effectsf



Tipranavir



Pharmacokinetic interaction unlikelyh


In vitro evidence of additive antiretroviral effectsh



Zidovudine



Pharmacokinetic interactions unlikely1


In vitro evidence of additive or synergistic antiretroviral effects1 14 79


Lamivudine Pharmacokinetics


Absorption


Bioavailability


Rapidly absorbed from GI tract; peak plasma concentrations achieved within 0.5–2 hours.1 18 Absolute bioavailability is 86–87% in HIV-infected individuals.1 18


Fixed-combination tablet containing lamivudine 150 mg and zidovudine 300 (Combivir) is bioequivalent to one 150-mg tablet of lamivudine and one 300-mg tablet of zidovudine given simultaneously.60


Fixed-combination tablet containing abacavir 600 mg and lamivudine 300 (Epzicom) is bioequivalent to two 300-mg tablets of abacavir and two 150-mg tablets of lamivudine given simultaneously.104


Fixed-combination tablet containing abacavir 300 mg, lamivudine 150 mg, and zidovudine 300 mg (Trizivir) is bioequivalent to a 300-mg abacavir tablet, a 150-mg lamivudine tablet, and a 300-mg zidovudine tablet given simultaneously.37


Food


Food does not appear to affect absorption.1 18


Special Populations


Peak plasma concentrations and AUCs in patients with hepatic impairment are similar to those in patients with normal hepatic function.1 18


Peak plasma concentrations and AUCs increased in patients with renal impairment.1 18


Absolute bioavailability is 66% in HIV-infected pediatric patients (4.8 months to 16 years of age).1


Distribution


Extent


Not well characterized; distributes into extravascular spaces.1 18


Distributed into CSF; concentrations in CSF may be 5.6–30.9% of concurrent plasma concentrations in HIV-infected children.1


Crosses the placenta and is distributed into milk.1 18


Plasma Protein Binding


<36%.1 18


Elimination


Metabolism


Metabolism is a minor route of elimination.1 18


Intracellularly, lamivudine is phosphorylated and converted by cellular enzymes to the active 5′-triphosphate metabolite.1 18


Elimination Route


Eliminated unchanged in urine by active organic cationic secretion.1 18


Half-life


5–7 hours.1 18


Half-life of 2 hours reported in children 4 months to 14 years of age.1


Special Populations


Pharmacokinetics not altered in patients with hepatic impairment.1 18


Half-life increased with diminishing renal function.1 18 Hemodialysis increases clearance; length of time of hemodialysis (4 hours) insufficient to substantially alter mean lamivudine exposure after single-dose administration.1 18 Not known whether lamivudine is removed by peritoneal dialysis or continuous (24 hour) hemodialysis.1 18


Stability


Storage


Oral


Solution

Epivir: 25°C in tightly closed bottles.1


Epivir-HBV: 20–25°C in tightly closed bottles.18


Tablets

Epivir and Epivir-HBV: 25°C (may be exposed to 15–30°C).1 18


Combivir: 2–30°C.60


Epzicom: 25°C (may be exposed to 15–30°C).104


Trizivir: 25°C (may be exposed to 15–30°C).37


Actions and SpectrumActions



  • Dideoxy analogue of cytidine.1




  • Pharmacologically related to other NRTIs (e.g., abacavir, didanosine, emtricitabine, stavudine, zidovudine); differs structurally from these drugs; also differs pharmacologically and structurally from other currently available antiretrovirals.1




  • Active in vitro against HIV-1 and HIV-2.1 2 3 10 Also active against HBV.11 12 18 24 26 59




  • Inhibits replication of HIV by interfering with viral RNA-directed DNA polymerase (reverse transcriptase).1




  • Inhibits replication of HBV by interfering with HBV polymerase.18




  • Strains of HIV-1 with reduced susceptibility to lamivudine have been produced in vitro and have emerged during therapy with the drug.1 10 31




  • HBV with reduced susceptibility to lamivudine have emerged during therapy.18 96 YMDD-mutant HBV detected in adults and children receiving the drug; mutant viruses associated with diminished treatment response.18




  • Strains of HIV resistant to lamivudine may be cross-resistant to some other NRTIs.1




  • Cross-resistance between lamivudine and PIs is highly unlikely since the drugs have different target enzymes.62 Cross-resistance between lamivudine and NNRTIs is considered to be low since the drugs bind at different sites on reverse transcriptase and have different mechanisms of action.62



Advice to Patients


Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.



  • Critical nature of compliance with HIV therapy.1 Importance of using lamivudine in conjunction with other antiretrovirals—not for monotherapy.1




  • Antiretroviral therapy is not a cure for HIV infection, and opportunistic infections still may occur.1 HIV transmission via sexual contact or sharing needles is not prevented by antiretrovirals.1




  • Lamivudine is not a cure for HBV infection; long-term benefits unknown; worsening of disease possible.18 Advise patients to report new symptoms to their clinician.18 Patients should be advised that deterioration of liver disease has occurred when treatment is discontinued and that any change in treatment should be discussed with the clinician.1


    Importance of testing for HIV in patients receiving Epivir-HBV for management of chronic HBV infection.18




  • Importance of reading the patient package insert for Epivir-HBV provided by the manufacturer.18




  • Importance of using Epivir, not Epivir-HBV, for treatment of HIV infection.1




  • Possibility of pancreatitis in pediatric patients; parents or guardians advised to monitor pediatric patients for signs and symptoms.1




  • Redistribution/accumulation of body fat may occur, with as yet unknown long-term health effects.1




  • Importance of informing clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal products.1 18




  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.1 18




  • Importance of advising patients of other important precautionary information.1 18 (See Cautions.)



Preparations


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

































Lamivudine

Routes



Dosage Forms



Strengths



Brand Names



Manufacturer



Oral



Solution



5 mg/mL



Epivir-HBV



GlaxoSmithKline



10 mg/mL



Epivir



GlaxoSmithKline



Tablets, film-coated



100 mg



Epivir-HBV



GlaxoSmithKline



150 mg



Epivir(scored)



GlaxoSmithKline



300 mg



Epivir



GlaxoSmithKline























Lamivudine Combinations

Routes



Dosage Forms



Strengths



Brand Names



Manufacturer



Oral



Tablets, film-coated



150 mg with Abacavir Sulfate 300 mg (of abacavir) and Zidovudine 300 mg



Trizivir



GlaxoSmithKline



150 mg with Zidovudine 300 mg



Combivir



GlaxoSmithKline



300 mg with Abacavir Sulfate 600 mg (of abacavir)



Epzicom



GlaxoSmithKline


Comparative Pricing


This pricing information is subject to change at the sole discretion of DS Pharmacy. This pricing information was updated 04/2011. Actual costs to patients will vary depending on the use of specific retail or mail-order locations and health insurance copays.


Combivir 150-300MG Tablets (VIIV HEALTHCARE): 30/$466.01 or 60/$915.92


Epivir 10MG/ML Solution (VIIV HEALTHCARE): 240/$109.99 or 720/$309.96


Epivir 300MG Tablets (VIIV HEALTHCARE): 30/$433.15 or 90/$1230.75


Epivir HBV 100MG Tablets (GLAXO SMITH KLINE): 60/$748.02 or 180/$2219.96


Trizivir 300-150-300MG Tablets (VIIV HEALTHCARE): 60/$1516.36 or 180/$4255.72



Disclaimer

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmaci

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