Approximately 2 million of children worldwide are living with HIV as of 2015. Only about half of them are receiving antiretroviral treatment. It was estimated that circa 400 children get infected every day. Most of them are infected due to mother-to-child transmission. However, this transmission may be effectively reduced up to 2% if all the preventive measures are performed.
Principles of treatment
HIV replication damages the immune system and results in AIDS. Antiretroviral therapy is not able to kill the virus, but it slows down the virus replication and postpone the development of AIDS. The treatment should be started as soon as possible.
The most effective is the treatment which includes the combination of anti-HIV drugs with which the patient hasn’t been treated in the past and that are not cross-resistant to other drugs that the patient has already received. Monotherapy is not recommended as drug resistance develops.
The combinations of antiretroviral drugs should be used according to the appropriate schedules and dosages. The HIV treatment regimens include at least 3 medicines from 2 or more ART classes. The regimen should be as simple as possible, to make it easy for an infected individual. This will improve the compliance and adherence to treatment.
Indications for starting treatment
ART should be initiated for:
- Infants under 36 months of age, regardless of viral load and CD4+ count;
- For children older than 36 months and under 59 months at 3d and 4th stages of HIV infection treatment should be started immediately, regardless of viral load and CD4+ count; at the 1st and 2d stages the indications for ART include the CD4+ count of less than 750 per μL and viral load of more than 100.000 RNA copies per 1 ml;
- For children older than 5 years at 3d and 4th stages of HIV infection treatment should be started immediately, regardless of viral load and CD4+ count; at the 1st and 2d stages the indications for ART include the CD4+ count of less than 500 per μL and viral load of more than 100.000 RNA copies per 1 ml;
Four groups of drugs are available now for the treatment of HIV infection:
- Reverse trancriptase inhibitors
Zidovudine, didanosine, zalcitabine, stavudine, lamivudine, abacavir
Nucleotide analogue tenofovir
Nonnucleoside reverse transcriptase inhibitors:
Nevirapine, delavirdine, efavirenz
- Protease inhibitors
Saquinavir, indinavir, ritonavir, nelfinavi, amprenavir, fosamprenavir, atazanavir, tipranavir, and darunavir
- Entry inhibitors (CCR5 co-receptor antagonists)
- Integrase inhibitors
As it may be difficult for children to swallow tablets antriretroviral drugs are available in liquid pharmaceutical formulations.
Combinations used for treatment in children
Usually for the treatment of children under 12 years is prescribed a combination of abacavir and lamivudine. Other common combinations are zidovudine + lamivudine, zidovudine + abacavir. However, zidovudine may be dangerous when a child is suffering from anemia of myelosuppression.
Tenofovir + emtricitabine is an alternative combination.
For children who were exposed to nevirapine in utero a combination of lopinavir and ritonavir is preferred. Older children may receive ritonavir in combination with either atazanavir, darunavir, fosamprenavir, saquinavir or tipranavir.
Nevirapine is the only nonnucleoside reverse transcriptase inhibitor that may be used for treatment of infants under the age of 3 years. For children older than 3 efavirenz is a drug of choice.