Instgra (Dolutegravir 50mg)

Instgra general information

What is Instgra used for?

Instgra tablets 50mg are used to treat Human Immunodeficiency Virus (HIV) infection, in combination with other HIV medications, in adults and children over 12 years of age and weighing 40 kg or more.  HIV impairs the immune system by attacking specific immune cells called CD4⁺ cells, a type of white blood cell involved in fighting infection, which can lead to opportunistic life-threatening infection (infections that would not normally be harmful).  If too many CD4⁺ cells are destroyed this can result in acquired immune deficiency syndrome (AIDS).  Instgra tablets 50mg help prevent or slow down the ability of HIV to replicate, which reduces the viral load by keeping the amount virus down to a low level and this results in an increase in CD4 cell numbers, so that the immune system can recover reducing the risk of disease progression. 

How does Instgra work?

Instgra tablets 50mg contains the antiretroviral dolutegravir, a second generation integrase strand transfer inhibitor.  Dolutegravir in Instgra tablets 50mg inhibits the catalytic activity of the enzyme HIV-1 integrase, an HIV-encoded enzyme that is essential for viral replication.  HIV is a retrovirus, which is an RNA virus that produces an enzyme called reverse transcriptase to transcribe its RNA into DNA.  Another viral enzyme, HIV-integrase, is used to insert or integrate viral DNA into the host cell genome during the early phase of infection.  Once integrated into the host cell DNA the viral DNA is replicated, transcribed into RNA and translated into viral proteins, the process known as gene expression, so that the viral proteins needed to make to virus particles are produced alongside host cell proteins. By blocking the action of viral integrase, dolutegravir in Instgra tablets 50mg prevents replication of the virus and thereby inhibits production of new infectious viral particles.  Instgra tablets 50mg slow down the replication of HIV within your body but does not kill the virus already incorporated in the CD4⁺ cells or prevent the spread of the infection to others.   

What does Instgra contain?

Instgra tablets 50mg contain the active ingredient antiretroviral dolutegravir, an antiretroviral used to treat HIV infection.

Treating HIV infection with Instgra

Instgra tablets 50mg contain the antiretroviral drug dolutegravir, an inhibitor of the viral integrase enzyme.  HIV impairs the immune system by attacking specific immune cells called CD4⁺ cells that are involved in fighting infection, and this can lead to opportunistic life-threatening infection (infections that would not normally be harmful), including pneumonia, herpes virus infections, and Mycobacterium avium complex (MAC) infection.  If too many CD4⁺ cells are destroyed this can result in acquired immune deficiency syndrome (AIDS).  HIV is a retrovirus, which is an RNA virus that produces an enzyme called reverse transcriptase to transcribe its RNA into DNA.  Another viral enzyme, integrase, is used to insert or integrate viral DNA into the host cell genome during the early phase of infection.  Dolutegravir in Instgra tablets 400mg works by blocking the action of the viral integrase and this inhibits viral replication and thereby inhibits production of new infectious viral particles.  Instgra tablets 50mg are used in combination with other HIV medications to slow down the replication of HIV within your body but they do not kill the virus already incorporated in the CD4⁺ cells or prevent the spread of the infection to others. 

What are the side effects of Instgra?

The most commonly reported side effects when taking Instgra include headache, dizziness, nausea, vomiting, diarrhoea, abdominal discomfort or pain, rash, itching, fatigue, trouble sleeping, abnormal dreams, depression.

When should Instgra not be used?

You should not use Instgra tablets 50mg if you:

• are allergic to dolutegravir or any ingredients in Instgra
• are pregnant or are breastfeeding
• are taking medicines that interact with Instgra or only after discussion and instruction from your doctor including the anti-infective rifampicin, the antiarrhythmics dofetilide and pilsicainide, the anticonvulsants carbamazepine and phenytoin, the antidiabetic metformin, St John’s Wort for depression
• are taking calcium or iron supplements or antacids containing aluminium and/or magnesium, take 2 hours after or 6 hours before
• are taking certain other combinations of antiretrovirals as these may affect Instgra including, etravirine, efavirenz, fosamprenavir/ritonavir, nevirapine or tipranavir/ritonavir

What medications interact with Instgra?

Several medications interact with Instgra tablets 50mg and should either not be taken while you are taking Instgra or only after discussion and instruction from your doctor:

• Drugs that cause a serious reaction with Instgra: the antiarrhythmics dofetilide and pilsicainide 
• Drugs that affect Instgra: the anticonvulsants carbamazepine and phenytoin, antacids containing aluminium and/or magnesium (take 2 hours after or 6 hours before), St John’s Wort for depression
• Drugs that are affected by Instgra: the antiarrhythmics dofetilide and pilsicainide, the antidiabetic metformin

How should Instgra be taken?

You should take your Instgra tablets 50mg swallowed whole with a glass of water once daily, with or without food and in combination with other antiretroviral drugs that have been prescribed.  If you have an HIV infection that is resistant to other antiretrovirals of the same class, your doctor may recommend that you take your Instgra tablets 50mg twice daily.  If you are taking are taking calcium or iron supplements or antacids containing aluminium and/or magnesium, you should take them take 2 hours after or 6 hours before taking your Instgra tablets 50mg.  You should continue to take your Instgra tablets 50mg for as long as recommended by your doctor, and you will be monitored carefully to ensure that you do not develop any serious side effects, in which case your doctor will probably recommend that you stop taking your Instgra tablets 50mg. 

How long should you take Instgra?

You should continue to take your Instgra tablets 50mg for as long as recommended by your doctor.

Missed dose of Instgra

If you miss a dose of Instgra tablets 50mg 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 Instgra be stored?

You should store your Instgra tablets 50mg below 25°C in a cool dry place.