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Drug Details
KIVEXA Film-Coated Tablets
- Drug Class Description
Nucleoside Reverse Transcriptase Inhibitors (NRTIs) - Generic Name
Abacavir, Lamivudine - Presentation
Film-coated tablet. Orange, film-coated, modified capsule shaped tablets, debossed with GS FC2 on one side. - Description
Each film-coated tablet contains 600 mg of abacavir (as sulfate) and 300 mg lamivudine. Excipients Sunset yellow (E110) 1.7 mg per tablet - Indications
Kivexa is a fixed-dose combination of two nucleoside analogues (abacavir and lamivudine). It is indicated in antiretroviral combination therapy for the treatment of Human Immunodeficiency Virus (HIV) infection in adults and adolescents from 12 years of age.
The demonstration of the benefit of the combination abacavir/lamivudine as a once daily regimen in antiretroviral therapy, is mainly based on results of one study performed in primarily asymptomatic treatment-naïve adult patients.
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, unless no other therapeutic option is available in these patients, based on the treatment history and resistance testing.
- Adult Dosage
Therapy should be prescribed by a physician experienced in the management of HIV infection.
The recommended dose of Kivexa in adults and adolescents is one tablet once daily.
Kivexa should not be administered to adults or adolescents who weigh less than 40 kg because it is a fixed-dose tablet that cannot be dose reduced.
Kivexa can be taken with or without food.
Kivexa is a fixed-dose tablet and should not be prescribed for patients requiring dosage adjustments. Separate preparations of abacavir or lamivudine are available in cases where discontinuation or dose adjustment of one of the active substances is indicated. In these cases the physician should refer to the individual product information for these medicinal products.
Renal impairment: Kivexa is not recommended for use in patients with a creatinine clearance < 50 ml/min.
Hepatic impairment: No data are available in patients with moderate hepatic impairment, therefore the use of Kivexa is not recommended unless judged necessary. In patients with mild and moderate hepatic impairment close monitoring is required, and if feasible, monitoring of abacavir plasma levels is recommended. Kivexa is contraindicated in patients with severe hepatic impairment.
Elderly: No pharmacokinetic data are currently available in patients over 65 years of age. Special care is advised in this age group due to age associated changes such as the decrease in renal function and alteration of haematological parameters.
Children: Kivexa is not recommended for treatment of children less than 12 years of age as the necessary dose adjustment cannot be made.
- Child Dosage
Kivexa is not recommended for treatment of children less than 12 years of age as the necessary dose adjustment cannot be made. - Elderly Dosage
No pharmacokinetic data are currently available in patients over 65 years of age. Special care is advised in this age group due to age associated changes such as the decrease in renal function and alteration of haematological parameters. - Contra Indications
Kivexa is contraindicated in patients with known hypersensitivity to the active substances or to any of the excipients.
- Special Precautions
The special warnings and precautions relevant to abacavir and lamivudine are included in this section. There are no additional precautions and warnings relevant to Kivexa.
Hypersensitivity Reaction In clinical studies approximately 5% of subjects receiving abacavir develop a hypersensitivity reaction. Some of these cases were life-threatening and resulted in a fatal outcome despite taking precaution. Studies have shown that carriage of the HLA-B*5701 allele is associated with a significantly increased risk of a hypersensitivity reaction to abacavir. Based on the prospective study CNA106030 (PREDICT-1), use of pre-therapy screening for the HLA-B*5701 allele and subsequently avoiding abacavir in patients with this allele significantly reduced the incidence of abacavir hypersensitivity reactions. In populations similar to that enrolled in the PREDICT-1 study, it is estimated that 48% to 61% of patients with the HLA-B*5701 allele will develop a hypersensitivity reaction during the course of abacavir treatment compared with 0% to 4% of patients who do not have the HLA-B*5701 allele. These results are consistent with those of prior retrospective studies.
As a consequence, 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, unless no other therapeutic option is available based on the treatment history and resistance testing. In any patient treated with abacavir, the clinical diagnosis of suspected hypersensitivity reaction must remain the basis of clinical decision-making. It is noteworthy that among patients with a clinically suspected hypersensitivity reaction, a proportion did not carry HLA-B*5701.
Therefore, even in the absence of HLA-B*5701 allele, it is important to permanently discontinue abacavir and not rechallenge with abacavir if a hypersensitivity reaction cannot be ruled out on clinical grounds, due to the potential for a severe or even fatal reaction. Skin patch testing was used as a research tool for the PREDICT-1 study but has no utility in the clinical management of patients and therefore should not be used in the clinical setting.
•Clinical Description Hypersensitivity reactions are characterised by the appearance of symptoms indicating multi-organ system involvement. Almost all hypersensitivity reactions will have fever and/or rash as part of the syndrome. Other signs and symptoms may include respiratory signs and symptoms such as dyspnoea, sore throat, cough, and abnormal chest x-ray findings (predominantly infiltrates, which can be localised), gastrointestinal symptoms, such as nausea, vomiting, diarrhoea, or abdominal pain, and may lead to misdiagnosis of hypersensitivity as respiratory disease (pneumonia, bronchitis, pharyngitis), or gastroenteritis.
Other frequently observed signs or symptoms of the hypersensitivity reaction may include lethargy or malaise and musculoskeletal symptoms (myalgia, rarely myolysis, arthralgia). The symptoms related to this hypersensitivity reaction worsen with continued therapy and can be life- threatening. These symptoms usually resolve upon discontinuation of abacavir.
•Clinical Management >Hypersensitivity reaction symptoms usually appear within the first six weeks of initiation of treatment with abacavir, although these reactions may occur at any time during therapy . Patients should be monitored closely, especially during the first two months of treatment with abacavir, with consultation every two weeks. Patients who are diagnosed with a hypersensitivity reaction whilst on therapy MUST discontinue Kivexa immediately. Kivexa, or any other medicinal product containing abacavir (Ziagen or Trizivir), MUST NEVER be restarted in patients who have stopped therapy due to a hypersensitivity reaction.
Restarting abacavir following a hypersensitivity reaction results in a prompt return of symptoms within hours. This recurrence is usually more severe than on initial presentation, and may include life-threatening hypotension and death. To avoid a delay in diagnosis and minimise the risk of a life-threatening hypersensitivity reaction, Kivexa must 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 medicinal products). Special care is needed for those patients simultaneously starting treatment with Kivexa and other medicinal products known to induce skin toxicity (such as non-nucleoside reverse transcriptase inhibitors - NNRTIs). This is because it is currently difficult to differentiate between rashes induced by these products and abacavir related hypersensitivity reactions.
•Management after an interruption of Kivexa therapy If therapy with Kivexa has been discontinued for any reason and restarting therapy is under consideration, the reason for discontinuation must be established to assess whether the patient had any symptoms of a hypersensitivity reaction. If a hypersensitivity reaction cannot be ruled out, Kivexa or any other medicinal product containing abacavir (Ziagen or Trizivir ) must not be restarted. Hypersensitivity reactions with rapid onset, including life-threatening reactions have occurred after restarting abacavir in patients who had only one of the key symptoms of hypersensitivity (skin rash, fever, gastrointestinal, respiratory or constitutional symptoms such as lethargy and malaise) prior to stopping abacavir. The most common isolated symptom of a hypersensitivity reaction was a skin rash. Moreover, on very rare occasions hypersensitivity reactions have been reported in patients who have restarted therapy, and who had no preceding symptoms of a hypersensitivity reaction. In both cases if a decision is made to restart abacavir this must be done in a setting where medical assistance is readily available.
•Essential patient information Prescribers must ensure that patients are fully informed regarding the following information on the hypersensitivity reaction:
- Patients must be made aware of the possibility of a hypersensitivity reaction to abacavir that may result in a life-threatening reaction or death.
- Patients developing signs or symptoms possibly linked with a hypersensitivity reaction MUST CONTACT their doctor IMMEDIATELY. - Patients who are hypersensitive to abacavir should be reminded that they must never take Kivexa or any other medicinal product containing abacavir (Ziagen or Trizivir) again.
- In order to avoid restarting abacavir, patients who have experienced a hypersensitivity reaction should dispose of their remaining Kivexa tablets in their possession in accordance with the local requirements, and ask their doctor or pharmacist for advice.
- Patients who have stopped Kivexa for any reason, and particularly due to possible adverse reactions or illness, must be advised to contact their doctor before restarting.
- Patients should be advised of the importance of taking Kivexa regularly. - Each patient should be reminded to read the Package Leaflet included in the Kivexa package.
- They should be reminded of the importance of removing the Alert Card included in the package, and keeping it with them at all times.Lactic acidosis: lactic acidosis, usually associated with hepatomegaly and hepatic steatosis, has been reported with the use of nucleoside analogues. Early symptoms (symptomatic hyperlactatemia) include benign digestive symptoms (nausea, vomiting and abdominal pain), non-specific malaise, loss of appetite, weight loss, respiratory symptoms (rapid and/or deep breathing) or neurological symptoms (including motor weakness).
Lactic acidosis has a high mortality and may be associated with pancreatitis, liver failure, or renal failure. Lactic acidosis generally occurred after a few or several months of treatment. Treatment with nucleoside analogues should be discontinued in the setting of symptomatic hyperlactatemia and metabolic/lactic acidosis, progressive hepatomegaly, or rapidly elevating aminotransferase levels.
Caution should be exercised when administering nucleoside analogues to any patient (particularly obese women) with hepatomegaly, hepatitis or other known risk factors for liver disease and hepatic steatosis (including certain medicinal products and alcohol). Patients co-infected with hepatitis C and treated with alpha interferon and ribavirin may constitute a special risk. Patients at increased risk should be followed closely.Lipodystrophy: combination antiretroviral therapy has been associated with the redistribution of body fat (lipodystrophy) in HIV patients. The long-term consequences of these events are currently unknown. Knowledge about the mechanism is incomplete. A connection between visceral lipomatosis and protease inhibitors (PIs) and lipoatrophy and nucleoside reverse transcriptase inhibitors (NRTIs) has been hypothesised. A higher risk of lipodystrophy has been associated with individual factors such as older age, and with drug related factors such as longer duration of antiretroviral treatment and associated metabolic disturbances. Clinical examination should include evaluation for physical signs of fat redistribution. Consideration should be given to the measurement of fasting serum lipids and blood glucose. Lipid disorders should be managed as clinically appropriate.
Pancreatitis: pancreatitis has been reported, but a causal relationship to lamivudine and abacavir is uncertain.
Clinical studies: the benefit of the combination of abacavir and lamivudine as a once daily regimen is mainly based on a study performed in combination with efavirenz, in antiretroviral-naïve adults patients.
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.
Liver disease: if lamivudine is being used concomitantly for the treatment of HIV and HBV, additional information relating to the use of lamivudine in the treatment of hepatitis B infection is available in the Zeffix SPC.
The safety and efficacy of Kivexa has not been established in patients with significant underlying liver disorders. Kivexa is contraindicated in patients with severe hepatic impairment.
Patients with chronic hepatitis B or C and treated with combination antiretroviral therapy are at an increased risk of severe and potentially fatal hepatic adverse events. In case of concomitant antiviral therapy for hepatitis B or C, please refer also to the relevant product information for these medicinal products.
If Kivexa is discontinued in patients co-infected with hepatitis B virus, periodic monitoring of both liver function tests and markers of HBV replication is recommended, as withdrawal of lamivudine may result in an acute exacerbation of hepatitis (see Zeffix SPC).
Patients with pre-existing liver dysfunction, including chronic active hepatitis have an increased frequency of liver function abnormalities during combination antiretroviral therapy, and should be monitored according to standard practice. If there is evidence of worsening liver disease in such patients, interruption or discontinuation of treatment must be considered.
Mitochondrial dysfunction: 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. The main adverse events reported are haematological disorders (anaemia, neutropenia), metabolic disorders (hyperlactatemia, hyperlipasemia). These events are often transitory. Some late-onset neurological disorders have been reported (hypertonia, convulsion, abnormal behaviour). Whether the neurological disorders are transient or permanent is currently unknown. Any child exposed in utero to nucleoside and nucleotide analogues, even HIV-negative children, should have clinical and laboratory follow-up and should be fully investigated for possible mitochondrial dysfunction in case of relevant signs or symptoms. These findings do not affect current national recommendations to use antiretroviral therapy in pregnant women to prevent vertical transmission of HIV.
Immune Reactivation Syndrome: in HIV-infected patients with severe immune deficiency at the time of institution of combination antiretroviral therapy (CART), an inflammatory reaction to asymptomatic or residual opportunistic pathogens may arise and cause serious clinical conditions, or aggravation of symptoms. Typically, such reactions have been observed within the first few weeks or months of initiation of CART. Relevant examples are cytomegalovirus retinitis, generalised and/or focal mycobacterial infections, and Pneumocystis carinii pneumonia. Any inflammatory symptoms should be evaluated and treatment instituted when necessary.
Osteonecrosis: Although the etiology is considered to be multifactorial (including corticosteroid use, alcohol consumption, severe immunosuppression, higher body mass index), cases of osteonecrosis have been reported particularly in patients with advanced HIV-disease and/or long-term exposure to combination antiretroviral therapy (CART). Patients should be advised to seek medical advice if they experience joint aches and pain, joint stiffness or difficulty in movement.
Excipients: Kivexa contains the azo colouring agent sunset yellow, which may cause allergic reactions.
Opportunistic infections: patients should be advised that Kivexa or any other antiretroviral therapy does not cure HIV infection and that they may still develop opportunistic infections and other complications of HIV infection. Therefore patients should remain under close clinical observation by physicians experienced in the treatment of these associated HIV diseases.
Transmission of HIV: patients should be advised that current antiretroviral therapy, including Kivexa, has not been proven to prevent the risk of transmission of HIV to others through sexual contact or blood contamination. Appropriate precautions should continue to be taken.
- Interactions
Kivexa contains abacavir and lamivudine, therefore any interactions identified for these individually are relevant to Kivexa. Clinical studies have shown that there are no clinically significant interactions between abacavir and lamivudine.
Abacavir and lamivudine are not significantly metabolised by cytochrome P450 enzymes (such as CYP 3A4, CYP 2C9 or CYP 2D6) nor do they inhibit or induce this enzyme system. Therefore, there is little potential for interactions with antiretroviral protease inhibitors, non-nucleosides and other medicinal products metabolised by major P450 enzymes. The interactions listed below should not be considered exhaustive but are representative of the classes of medicinal products where caution should be exercised.
Interactions relevant to abacavir
Potent enzymatic inducers such as rifampicin, phenobarbital and phenytoin may via their action on UDP-glucuronyltransferases slightly decrease the plasma concentrations of abacavir.
The metabolism of abacavir is altered by concomitant consumption of ethanol resulting in an increase in AUC of abacavir of about 41%. These findings are not considered clinically significant. Abacavir has no effect on the metabolism of ethanol.
Retinoid compounds are eliminated via alcohol dehydrogenase. Interaction with abacavir is possible but has not been studied.
In a pharmacokinetic study, coadministration of 600 mg abacavir twice daily with methadone showed a 35% reduction in abacavir Cmax and a 1 hour delay in tmax, but the AUC was unchanged. The changes in abacavir pharmacokinetics are not considered clinically relevant. In this study, abacavir increased the mean methadone systemic clearance by 22%. The induction of metabolizing enzymes cannot therefore be excluded. Patients being treated with methadone and abacavir should be monitored for evidence of withdrawal symptoms indicating under dosing, as occasionally methadone re-titration may be required.
Interactions relevant to lamivudine
The likelihood of metabolic interactions with lamivudine is low due to limited metabolism and plasma protein binding, and almost complete renal clearance. The possibility of interactions with other medicinal products administered concurrently with Kivexa should be considered, particularly when the main route of elimination is active renal secretion, especially via the cationic transport system e.g. trimethoprim. Other medicinal products (e.g. ranitidine, cimetidine) are eliminated only in part by this mechanism and were shown not to interact with lamivudine. The nucleoside analogues (e.g. zidovudine and didanosine) are not metabolised by this mechanism and are unlikely to interact with lamivudine.
Administration of trimethoprim/sulfamethoxazole 160 mg/800 mg results in a 40% increase in lamivudine exposure, because of the trimethoprim component. However, unless the patient has renal impairment, no dosage adjustment of lamivudine is necessary. The pharmacokinetics of trimethoprim or sulfamethoxazole are not affected. When concomitant administration with co-trimoxazole is warranted, patients should be monitored clinically. Co-administration of Kivexa with high doses of co-trimoxazole for the treatment of Pneumocystis carinii pneumonia (PCP) and toxoplasmosis should be avoided.
Co-administration of lamivudine with intravenous ganciclovir or foscarnet is not recommended until further information is available.
Lamivudine may inhibit the intracellular phosphorylation of zalcitabine when the two medicinal products are used concurrently. Kivexa is therefore not recommended to be used in combination with zalcitabine.
- Adverse Drug Reactions
The adverse reactions reported for Kivexa were consistent with the known safety profiles of abacavir and lamivudine when given as separate medicinal products. For many of these adverse reactions it is unclear whether they are related to the active substance, the wide range of other medicinal products used in the management of HIV infection, or whether they are a result of the underlying disease process.
<Abacavir hypersensitivity In clinical studies, approximately 5 % of subjects receiving abacavir developed a hypersensitivity reaction. In clinical studies with abacavir 600 mg once daily the reported rate of hypersensitivity remained within the range recorded for abacavir 300 mg twice daily. Some of these hypersensitivity reactions were life-threatening and resulted in fatal outcome despite taking precautions. This reaction is characterised by the appearance of symptoms indicating multi-organ/body-system involvement. Almost all patients developing hypersensitivity reactions will have fever and/or rash (usually maculopapular or urticarial) as part of the syndrome, however reactions have occurred without rash or fever. The signs and symptoms of this hypersensitivity reaction are listed below. These have been identified either from clinical studies or post marketing surveillance. Those reported in at least 10% of patients with a hypersensitivity reaction are in bold text. Skin Rash (usually maculopapular or urticarial) Gastrointestinal tract Nausea, vomiting, diarrhoea, abdominal pain, mouth ulceration Respiratory tract Dyspnoea, cough , sore throat, adult respiratory distress syndrome, respiratory failure Miscellaneous Fever, lethargy, malaise , oedema, lymphadenopathy, hypotension, conjunctivitis, anaphylaxis Neurological/Psychiatry< Headache , paraesthesia Haematological Lymphopenia Liver/pancreas Elevated liver function tests, hepatitis, hepatic failure Musculoskeletal Myalgia , rarely myolysis, arthralgia, elevated creatine phosphokinase Urology Elevated creatinine, renal failure Some patients with hypersensitivity reactions were initially thought to have gastroenteritis, respiratory disease (pneumonia, bronchitis, pharyngitis) or a flu-like illness. This delay in diagnosis of hypersensitivity has resulted in abacavir being continued or re-introduced, leading to more severe hypersensitivity reactions or death. Therefore, the diagnosis of hypersensitivity reaction should be carefully considered for patients presenting with symptoms of these diseases. Symptoms usually appeared within the first six weeks (median time to onset 11 days) of initiation of treatment with abacavir, although these reactions may occur at any time during therapy. Close medical supervision is necessary during the first two months, with consultations every two weeks. It is likely that intermittent therapy may increase the risk of developing sensitisation and therefore occurrence of clinically significant hypersensitivity reactions. Consequently, patients should be advised of the importance of taking Kivexa regularly. Restarting abacavir following a hypersensitivity reaction results in a prompt return of symptoms within hours. This recurrence of the hypersensitivity reaction was usually more severe than on initial presentation, and may include life-threatening hypotension and death.
Patients who develop this hypersensitivity reaction must discontinue Kivexa and must never be rechallenged with Kivexa, or any other medicinal product containing abacavir (Ziagen or Trizivir). To avoid a delay in diagnosis and minimise the risk of a life-threatening hypersensitivity reaction, abacavir must 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 medicinal products).
Hypersensitivity reactions with rapid onset, including life-threatening reactions have occurred after restarting abacavir in patients who had only one of the key symptoms of hypersensitivity (skin rash, fever, gastrointestinal, respiratory or constitutional symptoms such as lethargy and malaise) prior to stopping abacavir. The most common isolated symptom of a hypersensitivity reaction was a skin rash. Moreover, on very rare occasions hypersensitivity reactions have been reported in patients who have restarted therapy and who had no preceding symptoms of a hypersensitivity reaction. In both cases, if a decision is made to restart abacavir this must be done in a setting where medical assistance is readily available. Each patient must be warned about this hypersensitivity reaction to abacavir.Many of the adverse reactions listed in the table below occur commonly (nausea, vomiting, diarrhoea, fever, lethargy, rash) in patients with abacavir hypersensitivity. Therefore, patients with any of these symptoms should be carefully evaluated for the presence of this hypersensitivity reaction. If Kivexa has been discontinued in patients due to experiencing any one of these symptoms and a decision is made to restart a medicinal product containing abacavir, this must be done in a setting where medical assistance is readily available. Very rarely cases of erythema multiforme, Stevens-Johnson syndrome or toxic epidermal necrolysis have been reported where abacavir hypersensitivity could not be ruled out. In such cases medicinal products containing abacavir should be permanently discontinued.
The adverse reactions considered at least possibly related to abacavir or lamivudine are listed by body system, organ class and absolute frequency. Frequencies are defined as very common (> 1/10), common (> 1/100, < 1/10), uncommon (> 1/1000, < 1/100), rare (> 1/10,000, < 1/1000), very rare (< 1/10,000).
Body system Abacavir Lamivudine Blood and lymphatic systems disorders Uncommon: Neutropenia and anaemia (both occasionally severe), thrombocytopenia Very rare: Pure red cell aplasia Immune system disorders Common: hypersensitivity Metabolism and nutrition disorders Common: anorexia
Nervous system disorders Common : headache Common: Headache, insomnia. Very rare: Cases of peripheral neuropathy (or paraesthesia) have been reported Respiratory, thoracic and mediastinal disorders Common: Cough, nasal symptoms Gastrointestinal disorders Common : nausea, vomiting, diarrhoeaRare : pancreatitis has been reported, but a causal relationship to abacavir treatment is uncertain Common: Nausea, vomiting, abdominal pain or cramps, diarrhoea Rare : Rises in serum amylase. Cases of pancreatitis have been reported Hepatobiliary disorders Uncommon: Transient rises in liver enzymes (AST, ALT), Rare: Hepatitis Skin and subcutaneous tissue disorders Common : rash (without systemic symptoms) Very rare : erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis Common: Rash, alopecia Musculoskeletal and connective tissue disorders Common : Arthralgia, muscle disorders Rare: Rhabdomyolysis General disorders and administration site conditions Common : fever, lethargy, fatigue. Common: fatigue, malaise, fever. Cases of lactic acidosis, sometimes fatal, usually associated with severe hepatomegaly and hepatic steatosis, have been reported with the use of nucleoside analogues.
Combination antiretroviral therapy has been associated with redistribution of body fat (lipodystrophy) in HIV patients including the loss of peripheral and facial subcutaneous fat, increased intra-abdominal and visceral fat, breast hypertrophy and dorsocervical fat accumulation (buffalo hump).
Combination antiretroviral therapy has been associated with metabolic abnormalities such as hypertriglyceridaemia, hypercholesterolaemia, insulin resistance, hyperglycaemia and hyperlactataemia.
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.
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 (CART). The frequency of this is unknown.