Abamune-L (Abacavir/Lamivudine 600mg/300mg) Tablets

Abamune-L general information

What is Abamune-L used for?

Human Immunodeficiency Virus (HIV) is a type of virus known as a retrovirus.  HIV is transmitted by direct contact with body fluids, such us from unprotected sex, breastfeeding, using contaminated syringes, or transfusion with contaminated blood.  Infection with HIV damages the immune system, which is your body’s defence against invasion with harmful organisms.  If left untreated, HIV infection can result in a condition called acquired immune deficiency syndrome (AIDS).  Abamune-L tablets 600/300mg are a fixed-dose combination medication used to treat HIV infection.  They help relieve acute symptoms of HIV infection and control the spread of the virus, to prevent the development of AIDS. 

How does HIV cause AIDS?

HIV damages the immune system by attacking specific immune cells called CD4 cells.  These are specialised white cells or T lymphocytes, also known as T helper cells, that interact with other immune cells like B lymphocytes and macrophages in fighting infection.  As HIV continues to attack and destroy CD4 cells, the immune system becomes weakened and cannot work effectively. 

Acute infection causes symptoms within 2-4 weeks that are like flu and include fever and headache.  You may also develop a rash.  At this stage, the virus is replicating rapidly, and the number of infectious virus particles in the body, known as the viral load, is very high.  If the virus persists untreated in the body, replication continues, but it slows down.  It is still highly contagious and is still causing damage to the immune system.  This chronic stage of infection can last months, even years. 

Eventually, the immune system is so damaged because too many CD4 cells have been destroyed, that it is unable to fight infection.  This is the final and life-threatening lead stage of HIV infection known as acquired immune deficiency syndrome (AIDS).  If you have been diagnosed with AIDS you will be severely immunocompromised, which means that you are highly susceptible to opportunistic infection.  These are infections that would not usually be harmful and include Herpes Simplex Virus, Cytomegalovirus (CMV) that causes pneumonia and gastroenteritis, and Mycobacterium avium complex (MAC) that infects the lungs.  Fungal infections of the mouth, lungs and brain can also cause serious problems.  Kaposi’s sarcoma is a virus-related cancer that is associated with HIV infection.  HIV is still very contagious at this stage, and AIDS has a poor prognosis, usually just a few years. 

How do retroviruses replicate?

The genetic material of retroviruses is RNA.  The only way a retrovirus can multiply is to convert its RNA to DNA, using an enzyme produced by the virus called reverse transcriptase.  Once a DNA copy has been made of the viral RNA, it can then get into (or integrate) the DNA of infected immune cells.  This stage of the infection process depends on a viral enzyme known as integrase.  Once integrated into the host immune cell DNA, the viral DNA can replicate, using the cellular equipment provided by the host cells. 

Antiretroviral therapy (ART)

Antiretroviral drugs are drugs that are only effective against retroviruses.  Antiretroviral therapy (ART) is treatment using a combination of different classes of antiretroviral drugs that work by different mechanisms.  Using a combination of drugs reduces the risk of the virus developing resistance to treatment.  So if one medicine does not work, another one in the combination will. 

Treatment for HIV is most effective if started as soon as symptoms appear and before the viral load increases rapidly.  Although ART cannot cure the disease, it can reduce the viral load, reduce the risk of viral transmission, and improve quality of life. 

How does Abamune-L work?

Abamune-L tablets contain the antiretroviral drugs abacavir (600mg) and lamivudine (300mg) that are used in combination to treat infection with Human Immunodeficiency Virus (HIV).  Abamune-L tablets work by inhibiting the action of the viral-specific enzyme reverse transcriptase, and are only effective against retroviruses like HIV. 

Lamivudine and abacavir in Abamune-L tablets are both nucleoside analogue reverse transcriptase inhibitors (NRTI), which means they have a similar structure to natural nucleosides.  Lamivudine is an analogue of cytidine and abacavir is an analogue of guanosine.  A nucleoside is a building block of DNA that is needed by the virus to replicate.  Nucleoside analogues, like lamivudine and abacavir, become incorporated into the DNA that is copied from the viral RNA by reverse transcriptase.  Incorporation of nucleoside analogues into the growing DNA chain blocks the action of reverse transcriptase.  The result is that the viral DNA chain is terminated so that it cannot become integrated into the DNA of the infected immune cell.  Therefore, no more HIV can be produced. 

Abamune-L tablets slow down the replication of HIV within your body and the progression of the disease.  However, it does not kill the virus already incorporated in the immune cells or prevent the spread of the infection to others. 

What does Abamune-L contain?

Abamune-L contains the active ingredients abacavir (600mg) and lamivudine (300mg) that are used in combination to treat infection with Human Immunodeficiency Virus (HIV). 

What are the side effects of Abamune-L?

Most medications have some side effects, but they are not experienced by everyone.  Some side effects are commonly experienced when taking Abamune-L tablets 600/300mg, but others are not so common, and you should discuss any problems or concerns with your primary care physician. 

Common side effects when taking Abamune-L include hypersensitivity reaction, particularly to abacavir, nausea, vomiting, diarrhoea, fever, lethargy, rash, anorexia, headache, fever, lethargy, fatigue.

When should Abamune-L not be used?

Have a talk with your primary healthcare physician before taking Abamune-L tablets 600/300mg so that you have a full understanding of what this medicine is for and how to use it.  There are some reasons for not taking a medication; these are called contraindications, and for Abamune-L you should consider the following before taking Abamune-L:

• Have you ever had an unusual reaction or an allergy when taking Abamune-L?
• Are you pregnant or breastfeeding?
• Do you have a serious liver disease like hepatitis or cirrhosis?
• Do you have a heart condition, including ischemic heart disease or high blood pressure?

Note: An allergic reaction to abacavir can be life-threatening.  Lamivudine can cause exacerbation of Hepatitis.  Lactic acidosis is a rare but potentially fatal condition that has been reported when taking antiretroviral nucleoside analogues like Abamune-L. 

What medications interact with Abamune-L?

Some medicines interact with Abamune-L tablets 600/300mg and may affect the way it works, or are affected by Abamune-L or increase side effects; you should discuss possible interactions with your primary care physician.  These may include the antibiotic co-trimoxazole (trimethoprim-sulphamethoxazole), methadone for pain relief or for treatment of narcotic withdrawal, medicines containing the sweetener sorbitol. 

If other medications may interact with Abamune-L, your doctor will discuss these with you. 

How should Abamune-L be taken and for how long?

You should take your Abamune-L tablets 600/300mg swallowed whole with a glass of water with or without food, once daily.  The dose you take will depend on your condition, whether you have taken, or are currently taking other antiretroviral drugs and your doctor’s recommendation.  Your dose may be increased or decreased depending on how well you respond and whether you have any reactions or side effects.  You should continue to take your Abamune-L tablets 600/300mg regularly for as long as recommended by your doctor.  It will help control the HIV infection but does not cure it.  Do not stop taking your tablets even if you feel better without discussion with your doctor.  

Missed dose of Abamune-L

If you miss a dose of Abamune-L tablets 600/300mg take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose.  Do not take a double dose.

How should Abamune-L be stored?

You should store your Abamune-L tablets 600/300mg below 25°C in a cool dry place.