Abacavir/ Lamivudine

Registered South African indications:

• HIV infection

Contraindications

South African manufacturer recommendations
120/60 (mg) & 60/30 (mg) (dsp, tab)

• Hypersensitivity to the active ingredients or any of the excipients in this combination product
• Pregnancy
• Breastfeeding
• Moderate (CrCl<50ml/min) or severe (CrCl<30ml/min) renal impairment
• Moderate (Child-Pugh B (score 7-9 points)) and or severe (Child Pugh C (score 10-15 points)) hepatic impairment 
• Weight ≥25kg
• Infants ≤6 weeks of age
• Phenylketonuria

600/300 (mg) (fct, tab)

• Hypersensitivity to the active ingredients or any of the excipients in this combination product
• Moderate and severe hepatic impairment
• Children <12 years of age (weighing <40kg)

International manufacturer recommendations

• Hypersensitivity to the active ingredients or any of the excipients in this combination product

Cautions

South African manufacturer recommendations
120/60 (mg) & 60/30 (mg) (dsp, tab)

• Mild (CrCl≥50ml/min) renal impairment
• Mild (Child-Pugh A) hepatic impairment
  - Pre-existing hepatic dysfunction including chronic active hepatitis
  - Co-infection with chronic hepatitis B virus (HBV) disease (See additional prescribing points)
  - Known risk factors for liver disease
• Elderly
• Low CD4 counts
• HIV negative infants exposed in utero and/or post-natally to nucleoside analogues
• Advanced HIV disease and/or long-term exposure to combination antiretroviral therapy (cART)
• Underlying risk of coronary heart disease
• Myocardial infarction risk factors
  - Smoking
  - Hypertension
  - Hyperlipidaemia
  - Diabetes mellitus
• Coadministration with zalcitabine
• May impair ability to drive and operate machinery

600/300 (mg) (fct, tab)

• Pregnancy
• Breastfeeding
• Renal impairment
• Mild (Child-Pugh A) hepatic impairment
  - Co-infection with chronic hepatitis B or C (See additional prescribing points)
  - Known risk factors for liver disease
• Elderly
• Advanced HIV disease and/or long-term exposure to combination antiretroviral therapy (cART)
• HIV negative infants exposed in utero and/or post-natally to nucleoside analogues
• Underlying risk of coronary heart disease
• Myocardial infarction risk factors
  - Smoking
  - Hypertension
  - Hyperlipidaemia
  - Diabetes mellitus
• Triple nucleoside therapy (See additional prescribing points)
• Coadministration with zalcitabine
• Coadministration with emtricitabine or emtricitabine-containing fixed-dose combinations

International manufacturer recommendations

• Pregnancy
• Breastfeeding
• Renal impairment
• Hepatic impairment
  - Pre-existing hepatic dysfunction, including chronic active hepatitis
  - Co-infection with chronic hepatitis B or C (See additional prescribing points)
• Elderly
• Triple nucleoside therapy (See additional prescribing points)
• Advanced HIV disease and/or long-term exposure to combination antiretroviral therapy (cART)
• Myocardial infarction risk factors
  - Smoking
  - Hypertension
  - Hyperlipidaemia
• Coadministration with any other medicinal agents containing lamivudine or emtricitabine
• Coadministration with cladribine

Forms avail. in SA and covered in this monograph: fct, tab

Dosages below include:

• South African manufacturer recommendations
• International manufacturer recommendations

South African manufacturer recommendations
HIV infection
Abacavir/ Lamivudine
600/300 (mg)

• Oral (fct,tab): 1 tab, dly

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Patients should have been stabilised on the individual medicines before being switched over to the abacavir/ lamivudine combination

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Therapy should be initiated by a medical practitioner experienced in the management of HIV infection

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Should not be administered if weight <40kg 

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Abacavir/ lamivudine is a fixed-dose tablet and should not be prescribed for patients requiring dosage adjustments

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Separate preparations of abacavir or lamivudine should be administered in cases where discontinuation or dose adjustment is indicated. Medical practitioners should refer to the individual product information for lamivudine and abacavir

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International manufacturer recommendations
HIV infection
Abacavir/ Lamivudine
600/300 (mg)

• Oral (fct): 1 tab, dly

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Weight should be at least 25kg

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Therapy should be prescribed by a physician experienced in the management of HIV infection

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Before initiating treatment with abacavir, screening for carriage of the HLA-B*5701 allele should be performed in any HIV-infected patient, irrespective of racial origin. Abacavir should not be used in patients known to carry the HLA-B*5701 allele

Paed. forms avail. in SA and covered in this monograph: dsp, tab

Dosages below include:

• South African manufacturer recommendations
• International manufacturer recommendations

South African manufacturer recommendations
HIV infection (Additional agent(s) required)
Abacavir/ Lamivudine
60/30 (mg)

• Younger than 3 months: No information available
• 3 months and older:<25kg: Oral (dsp, tab): Abacavir component: 8mg/kg/dose, 12hrly; Lamivudine component: 4mg/kg/dose, 12hrly

The recommended dose according to body weight is as follows:

Body weight (kg)	Recommended number of tablets (twice daily) Morning                    Evening		Number of tablets (once daily)
3–5,9	1 tablet	1 tablet	2 tablets
6–9,9	1,5 tablets	1,5 tablets	3 tablets
10–13,9	2 tablets	2 tablets	4 tablets
14–19,9	2,5 tablets	2,5 tablets	5 tablets
20–24,9	3 tablets	3 tablets	6 tablets

120/60 (mg)

• Younger than 3 months: No information available
• 3 months and older:<25kg: Oral (dsp, tab): See table below

The recommended dose according to body weight is as follows:

Weight range (kg)	Number of tablets (once daily)
3–5,9	1 tablet
6–9,9	1,5 tablets
10–13,9	2 tablets
14–19,9	2,5 tablets
20–24,9	3 tablets

• ≥25kg: Refer to the single ingredient formulations

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Patients should have been stabilised on the individual medicines before being switched over to the fixed-dose combination if similar doses of the actives can be achieved with the abacavir/ lamivudine combination

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Therapy should be initiated by a medical practitioner experienced in the management of HIV infection

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Abacavir/ lamivudine can be taken with or without food

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Abacavir/ lamivudine is a fixed-dose tablet and should not be prescribed for patients requiring dose adjustments

---

Separate preparations of abacavir or lamivudine should be administered in cases where discontinuation or dose adjustment is indicated. Medical practitioners should refer to the individual product information for lamivudine and abacavir

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For very young children who cannot swallow tablets, abacavir/ lamivudine  should be dispersed in water before administration: See additional prescribing points

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International manufacturer recommendations
HIV infection
Abacavir/ Lamivudine
600/300 (mg) 

• <25kg: Not recommended for use
• ≥25kg: See adult dosage

  ---

  Should not be administered to children who weigh <25 kg because it is a fixed-dose tablet that cannot be dose reduced

  ---

  Fixed-dose tablet and should not be prescribed for patients requiring dose adjustments

  ---

  Separate preparations of abacavir or lamivudine are available in cases where discontinuation or dose adjustment of one of the active substances is indicated. Refer to the individual product information for these medicinal agents

Pregnancy
South African manufacturer recommendations
 120/60 (mg) & 60/30 (mg) (dsp, tab)

• Contraindicated
• Safety of abacavir/ lamivudine in human pregnancy has not been established and an increased risk of birth defects cannot be excluded
• Both lamivudine and abacavir crossed the placenta in reproductive toxicity studies in animals. Early embryonic deaths occurred with lamivudine in rabbits at systemic exposures comparable to that achieved in humans. Abacavir demonstrated toxicity to the developing embryo and foetus in rats which resulted amongst others, in foetal oedema, skeletal variations/malformations, early intrauterine deaths and still births
• Mitochondrial dysfunction has been reported with the use of nucleoside analogues. Abacavir and lamivudine in combination should not be initiated during pregnancy, due to the risk of a hypersensitivity reaction to abacavir and possible mitochondrial damage to foetus. Nucleoside and nucleotide analogues have been demonstrated in vitro and in vivo to cause a variable degree of mitochondrial damage. There have been reports of mitochondrial dysfunction in HIV-negative infants exposed in utero and/or post-natally to nucleoside analogues

600/300 (mg) (fct, tab)

• Caution; not recommended
• The safety of abacavir/ lamivudine in human pregnancy has not been established. Abacavir/ lamivudine should not be used during pregnancy since teratogenicity and/or foetal toxicity cannot be excluded

International manufacturer recommendations

• Caution
• As a general rule, when deciding to use antiretroviral agents for the treatment of HIV infection in pregnant women and consequently for reducing the risk of HIV vertical transmission to the newborn, the animal data as well as the clinical experience in pregnant women should be taken into account
• Animal studies with abacavir have shown toxicity to the developing embryo and foetus in rats, but not in rabbits. Animal studies with lamivudine showed an increase in early embryonic deaths in rabbits but not in rats. Abacavir/ lamivudine may inhibit cellular DNA replication and abacavir has been shown to be carcinogenic in animal models. The clinical relevance of these findings is unknown. Placental transfer of abacavir and lamivudine has been shown to occur in humans
• In pregnant women treated with abacavir, more than 800 outcomes after first trimester exposure and more than 1000 outcomes after second and third trimester exposure indicate no malformative and foetal/neonatal effect. In pregnant women treated with lamivudine, more than 1000 outcomes from first trimester and more than 1000 outcomes from second and third trimester exposure indicate no malformative and foeto/neonatal effect. There are no data on the use of abacavir/ lamivudine in pregnancy, however, the malformative risk is unlikely in humans based on those data
• For patients co-infected with hepatitis who are being treated with a lamivudine containing medicinal agent such as abacavir/ lamivudine and subsequently become pregnant, consideration should be given to the possibility of a recurrence of hepatitis on discontinuation of lamivudine
• Nucleoside and nucleotide analogues have been demonstrated in vitro and in vivo to cause a variable degree of mitochondrial damage. There have been reports of mitochondrial dysfunction in HIV-negative infants exposed in utero and/or post-natally to nucleoside analogues

Breastfeeding
South African manufacturer recommendations
120/60 (mg) & 60/30 (mg) (dsp, tab)

• Contraindicated  
• Women on treatment with abacavir/ lamivudine should not breastfeed their infants. Lamivudine and probably also abacavir, are excreted into the breast milk of breastfeeding mothers. It is recommended that HIV infected woman do not breastfeed their infants under any circumstances in order to avoid transmission of HIV 

600/300 (mg) (fct, tab)

• Caution; not recommended 
• Abacavir/ lamivudine should not be used during breastfeeding since teratogenicity and/or foetal toxicity cannot be excluded
• Lamivudine is excreted in human milk at similar concentrations to those found in serum. It is expected that abacavir will also be secreted into human milk. Therefore, mothers on treatment with abacavir/ lamivudine should not breastfeed their babies
• HIV infected women should not breastfeed their infants in order to avoid transmission of HIV. In settings where formula feeding is not feasible, the local official breastfeeding and treatment guidelines should be followed when considering breastfeeding during antiretroviral therapy

International manufacturer recommendations

• Caution; not recommended 
• Abacavir and its metabolites are excreted into the milk of lactating rats
• Abacavir is also excreted into human milk. Based on more than 200 mother/child pairs treated for HIV, serum concentrations of lamivudine in breastfed infants of mothers treated for HIV are very low (<4% of maternal serum concentrations) and progressively decrease to undetectable levels when breastfed infants reach 24 weeks of age
• There are no data available on the safety of abacavir and lamivudine when administered to babies less than three months old
• It is recommended that HIV infected women do not breastfeed their infants under any circumstances in order to avoid transmission of HIV

​​​Fertility 

• Studies in animals showed that neither abacavir nor lamivudine had any effect on fertility

Renal Impairment
South African manufacturer recommendations
120/60 (mg) & 60/30 (mg) (dsp, tab)

• Mild (CrCl≥50ml/min): Caution; dose adjustment recommended 
  Dosage adjustment of lamivudine may be necessary in patients with mild renal impairment, due to a decreased clearance of lamivudine. However, a lamivudine dose reduction cannot be achieved with lamivudine in a fixed dose combination
• Moderate (CrCl<50ml/min): Contraindicated 
• Severe (CrCl<30ml/min): Contraindicated 

600/300 (mg) (fct, tab)

• Mild (CrCl≥50ml/min): Caution; dose adjustment recommended 
  Whilst no dosage adjustment of abacavir is necessary, in patients with renal impairment, a dose reduction of lamivudine is required due to decreased clearance
• Moderate to severe (CrCl<50ml/min): Caution; not recommended 

International manufacturer recommendations

• Mild (CrCl≥50ml/min): Caution; no dose adjustment recommended 
  Studies with lamivudine show that plasma concentrations (AUC) are increased in patients with renal impairment due to decreased clearance
• Moderate to severe (CrCl<50ml/min): Caution; not recommended
  Abacavir/ lamivudine fixed-dose combination is not recommended as necessary dose adjustment cannot be made

Hepatic Impairment

South African manufacturer recommendations

• Mild hepatic impairment (Child-Pugh A score 5-6): Caution; dose adjustment recommended  
  A dose reduction of abacavir may be required in patients with mild hepatic impairment. As dose reduction is not possible with fixed dose combination, the separate preparations of abacavir and lamivudine should be used
• Moderate hepatic impairment (Child-Pugh B (score 7-9 points): Contraindicated 
• Severe hepatic impairment Child-Pugh C (score 10-15 points): Contraindicated 

International manufacturer recommendations

• Mild hepatic impairment (Child-Pugh A score 5-6): Caution; no dose adjustment recommended 
  Close monitoring is required, including monitoring of abacavir plasma levels if feasible
• Moderate or severe hepatic impairment: Caution; no information available 
  Abacavir is primarily metabolised by the liver. No clinical data are available, therefore the use of abacavir/ lamivudine is not recommended unless judged necessary

Elderly

• Caution; no information available 

Porphyria Information

• Probably not porphyrinogenic (PNP) 

Drugs in Sport

• Permitted - No warnings

Abacavir
Central Nervous System Disorders 

• Headache
• Fatigue

Gastrointestinal Disorders 

• Nausea and vomiting
• Diarrhoea
• Pancreatitis

Endocrine and Metabolic Disorders

• Anorexia
• Lactic acidosis

Skin and Subcutaneous Tissue Disorders

• Rash (without systemic symptoms)
• Erythema multiforme
• Stevens-Johnson syndrome
• Toxic epidermal necrolysis

Immune, Blood and Lymphatic System Disorders

• Hypersensitivity
• Fever

Abacavir hypersensitivity
Central Nervous System Disorders

• Headache
• Paraesthesia
• Malaise

Cardiovascular Disorders

• Hypotension

Respiratory Disorders 

• Dyspnoea
• Cough
• Sore throat
• Adult respiratory distress syndrome
• Respiratory failure

Gastrointestinal Disorders

• Nausea and vomiting
• Diarrhoea
• Abdominal pain
• Mouth ulceration

Hepatobiliary Disorders 

• Increased liver function tests
• Hepatitis
• Hepatic failure

Genitourinary Disorders 

• Increased creatinine
• Renal failure

Musculoskeletal Disorders 

• Myalgia
• Myolysis
• Arthralgia
• Increased creatine phosphokinase

Skin and Subcutaneous Tissue Disorders

• Rash
  - Maculopapular 
  - Urticarial

Immune, Blood and Lymphatic System Disorders 

• Fever
• Lymphadenopathy
• Anaphylaxis
• Lymphopenia
• Oedema

Sensory Disorders

• Conjunctivitis

Lamivudine
Central Nervous System Disorders

• Headache
• Insomnia
• Peripheral neuropathy (or paraesthesia)
• Fatigue

Respiratory Disorders

• Cough
• Nasal symptoms

Gastrointestinal Disorders

• Nausea and vomiting
• Diarrhoea
• Abdominal pain or cramps
• Increased serum amylase
• Pancreatitis

Hepatobiliary Disorders

• Increased liver enzymes
  - Increased aspartate aminotransferase
  - Increased alanine transaminase
• Hepatitis

Endocrine and Metabolic Disorders

• Lactic acidosis

Musculoskeletal Disorders

• Arthralgia
• Muscle disorders
• Rhabdomyolysis

Skin and Subcutaneous Tissue Disorders

• Rash
• Alopecia
• Angioedema

Immune, Blood and Lymphatic System Disorders

• Neutropenia
• Anaemia 
• Thrombocytopenia
• Pure red cell aplasia
• Fever

(See additional prescribing points for adverse reaction due to antiretroviral use in general)

Abacavir

• Other medicinal agents containing lamivudine or emtricitabine
• UGT enzyme inducers
• UGT enzyme inhibitors
• Alcohol dehydrogenase substrates
• Riociguat

Lamivudine

• Other medicinal agents containing lamivudine or emtricitabine
• Organic cation transporters (OCT) inhibitors
• Cladribine
• Sorbitol solution
• Osmotic acting poly-alcohols
• Monosaccharide alcohols
• Xylitol
• Mannitol
• Lactitol
• Maltitol

• HLA-B*5701 genotype status

Specific cases may require

• Hepatic function
  - Bilirubin
  - Liver enzymes
• Blood glucose
• Haematologic parameters
• Lipid profile
• Viral load
• CD4 count
• Serum creatine kinase

Additional observations

• Signs and symptoms of hypersensitivity

Method of administration for very young children who cannot swallow tablets

• Abacavir/ lamivudine should be dispersed in water before administration
• The number of tablets to be administered to each patient will be determined by his or her body weight
• Remove the number of tablets recommended for one dose from the bottle with dry hands
• Place the tablet(s) in a container and add two teaspoons (10ml) of drinking water per tablet
• Swirl or stir until the tablets disperse completely. The suspension has a strawberry flavour
• The child should consume the entire quantity immediately
• Rinse the container with an additional small amount of drinking water and let the child drink the contents to assure that the whole dose is taken
• Do not mix the tablets with any liquid other than water

Clinical management of hypersensitivity

• Regardless of their HLA-B*5701 status, any patients developing signs or symptoms of hypersensitivity MUST contact their doctor immediately for advice
• If a hypersensitivity reaction is diagnosed, abacavir/ lamivudine MUST be discontinued immediately
• Abacavir/ lamivudine, or any other medicine, containing abacavir, MUST NEVER be restarted following a hypersensitivity reaction, as more severe symptoms will recur within hours and may include life-threatening hypotension and death
• To avoid a delay in diagnosis and minimise the risk of a life-threatening hypersensitivity reaction, abacavir/ lamivudine should be permanently discontinued if hypersensitivity cannot be ruled out, even when other diagnoses are possible (respiratory diseases, flu-like illness, gastroenteritis or reactions to other medications)
• Abacavir/ lamivudine, or any other medicine containing abacavir, should not be restarted even if a recurrence of symptoms occurs following re-challenge with alternative medication(s)

Immune reconstitution inflammatory syndrome

• Immune Reconstitution Inflammatory Syndrome (IRIS) is an immunopathological response resulting from the rapid restoration of pathogen-specific immune responses to pre-existing antigens combined with immune dysregulation, which occurs shortly after starting combination antiretroviral therapy (cART)
• Typically, such reaction presents by paradoxical deterioration of opportunistic infections being treated or with unmasking of an asymptomatic opportunistic disease, often with an atypical inflammatory presentation. IRIS usually develops within the first three months of initiation of ART and occurs more commonly in patients with low CD4 counts
• Common examples of IRIS reactions to opportunistic diseases are tuberculosis, cytomegalovirus retinitis, and cryptococcal meningitis. Appropriate treatment of the opportunistic disease should be instituted or continued, and ART continued. Inflammatory manifestations generally subside after a few weeks
• Severe cases may respond to glucocorticoids, but there is only limited evidence for this in patients with tuberculosis IRIS. Autoimmune disorders (such as Graves' disease) have also been reported as IRIS reactions; however, the reported time to onset is more variable and these events can occur many months after initiation of treatment

Lactic acidosis/ hyperlactataemia

• Use of abacavir/ lamivudine can result in potentially fatal lactic acidosis because of mitochondrial dysfunction. Clinical features are non-specific and include nausea, vomiting, abdominal pain, dyspnoea, fatigue and weight loss
• In patients with suspicious signs of biochemistry, measure the venous lactate level (normal <2 mmol/l) and the serum bicarbonate and respond as follows:
• Lactate 2-5mmol/l with minimum symptoms: switch to that are less likely to cause lactic acidosis
• Lactate 5-10mmol/l with symptoms and/or with reduced standard bicarbonate: Stop NRTIs and change treatment option. Once lactate has settled, use medicines that are less likely to cause lactic acidosis. Exclude other causes, (e.g. sepsis, uraemia, diabetic ketoacidosis, thyrotoxicosis and hyperthyroidism
• Lactate >10mmol/l: Stop all therapy (80% mortality)
• The above lactate values may not be applicable to paediatric patients. Caution should be exercised when administering abacavir/ lamivudine to patients with known risk factors for liver disease. Treatment with abacavir/ lamivudine should be suspended in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or hepatotoxicity

Co-infection with hepatitis B virus
120/60 (mg) & 60/30 (mg) (dsp, tab)

• Patients with chronic hepatitis B virus (HBV) disease may experience clinical or laboratory evidence of recurrent hepatitis upon discontinuation of lamivudine, which may have more severe consequences in patients with decompensated liver disease
• If abacavir/ lamivudine is discontinued in patients co-infected with hepatitis B virus, frequent monitoring of both liver function tests, and markers of HBV replication should be done

Co-infection with hepatitis B or C virus
600/300 (mg) (fct, tab)

• Patients with chronic hepatitis B or C and treated with antiretroviral therapy are at an increased risk for severe and potentially fatal hepatic adverse reactions. Medical practitioners should refer to current HIV treatment guidelines for the optimal management of HIV infection in patients co-infected with hepatitis B virus (HBV)
• In case of concomitant antiviral therapy for hepatitis B or C, please refer to the relevant professional information for these medicines
• Patients co-infected with HIV and HBV who discontinue abacavir/ lamivudine should be closely monitored with both clinical and laboratory follow-up after stopping treatment. In patients with advanced liver disease or cirrhosis, treatment discontinuation is not recommended since post treatment exacerbation of hepatitis may lead to hepatic decompensation
• Clinical study and marketed use of lamivudine have shown that some patients with chronic hepatitis B virus (HBV) disease may experience clinical or laboratory evidence of recurrent hepatitis upon discontinuation of lamivudine, which may have more severe consequences in patients with decompensated liver disease
• If  abacavir/ lamivudine is discontinued in patients co-infected with hepatitis B virus, periodic monitoring of both liver function tests and markers of HBV replication should be considered

Triple nucleoside therapy

• There have been reports of a high rate of virological failure, and of emergence of resistance at an early stage when abacavir and lamivudine were combined with tenofovir disoproxil fumarate as a once daily regimen
• The risk of virological failure with abacavir/ lamivudine might be higher than with other therapeutic options

Opportunistic infections

• Patients receiving abacavir/ lamivudine should be advised that they may continue to develop opportunistic infections and other complications of HIV infection, and therefore they should remain under close observation by healthcare professionals experienced in the treatment of patients with associated HIV disease. Regular monitoring of viral load and CD4 counts needs to be done

The risk of HIV transmission to others

• Patients should be advised that current antiretroviral therapy, including abacavir/ lamivudine, does not prevent the risk of transmission of HIV to others through sexual contact or blood contamination. Appropriate precautions should continue to be employed

Myocardial infarction

• There is some evidence of a possible association between abacavir use and an increased risk of myocardial infarction. As a precaution, the underlying risk of coronary heart disease should be considered when prescribing antiretroviral therapies, including abacavir and action taken to minimise all modifiable risk factors (e.g. hypertension, hyperlipidaemia, diabetes mellitus and smoking)

Additional adverse reactions associated with  antiretroviral therapy

• Weight and levels of blood lipids and glucose may increase during antiretroviral therapy
• In HIV-infected patients with severe immune deficiency at the time of initiation of combination antiretroviral therapy, an inflammatory reaction to asymptomatic or residual opportunistic infections may arise
• Autoimmune disorders (such as Graves' disease and autoimmune hepatitis) have also been reported to occur in the setting of immune reconstitution; however, the reported time to onset is more variable and these events can occur many months after initiation of treatment
• Cases of osteonecrosis have been reported, particularly in patients with generally acknowledged risk factors, advanced HIV disease or long-term exposure to combination antiretroviral therapy. The frequency of this is unknown

Abacavir and lamivudine are nucleoside reverse transcriptase inhibitors (NRTIs) and are potent selective inhibitors of HIV-1 and HIV-2 (LAV2 and EHO) replication. Both abacavir and lamivudine are metabolised sequentially by intracellular kinases to the respective 5'-triphosphate (TP) which are the active moieties. Lamivudine-TP and carbovir-TP (the active triphosphate form of abacavir) are substrates for and competitive inhibitors of HIV reverse transcriptase (RT). However, their main antiviral activity is through incorporation of the monophosphate form into the viral DNA chain, resulting in chain termination. Abacavir and lamivudine triphosphates show significantly less affinity for host cell DNA polymerases. No antagonistic effects in vitro were seen with lamivudine and other antiretrovirals (tested agents: didanosine, nevirapine and zidovudine). The antiviral activity of abacavir in cell culture was not antagonized when combined with the (NRTIs) didanosine, emtricitabine, stavudine, tenofovir or zidovudine, the non-nucleoside reverse transcriptase inhibitor (NNRTI) nevirapine, or the protease inhibitor (PI) amprenavir.

COMBINATION PREPARATIONS
Abacavir/ Lamivudine
Dispersible tablet 120mg/60mg

• Dumiva Dispersible Tablets (Mylan)

Tablet 120mg/60mg

• Divudine 120/60 (Cipla)

Film-coated tablet 600mg/300mg

• Auro abacavir lamivudine 600/300mg (Aurobindo Pharma)
• Dumiva (Mylan)
• Hetbaclam (Hetero Drugs SA)
• Heteruam 600/300mg (Hetero Drugs SA)
• Vexabax (Ranbaxy Pharmaceuticals)

Tablet 600mg/300mg

• Abacavir & Lamivudine Cipla 600/300 (Cipla)
• Kivexa (GSK) originator