Hesperian Health Guides

How to prevent HIV with ART

a woman taking a pill
Treatment is also prevention. It makes HIV spread less easily.

When someone is tested, discovers she has HIV, and starts taking anti-retroviral therapy (ART) faithfully, the amount of HIV in her blood goes down. This not only protects her health, but makes her much less likely to infect others. So if a woman with HIV is tested and taking treatment before she becomes pregnant (or even starts ART as soon as she finds out she is pregnant), her chance of infecting her baby is very low.

If everyone was tested for HIV, treated for HIV if needed, and given the support they need to stay on treatment, HIV would spread more slowly and almost all babies would be born without HIV.

PrEP (Pre-Exposure Prophylaxis)

ART medicines can also be used by people who do not have HIV, to protect themselves if they were exposed or they know they will be exposed. PrEP means people without HIV take HIV medicines regularly to protect themselves from becoming infected with HIV. For example,

  • some people have partners who will not use condoms.
  • someone may have a partner who uses injection drugs, which puts them both at a higher risk for getting HIV from sharing needles or syringes.
  • some people trade sex to survive and they may not have a choice in negotiating safer sex with their partners.
  • PrEP can also help a couple get pregnant more safely when one person has HIV and the other does not.

Using PrEP every day can keep these people from getting HIV.

PrEP is usually a combination of two antiretroviral medicines. Talk to a health worker for more information about PrEP.

Medicines for Pre-Exposure Prophylaxis (PrEP)
If you do not have HIV but are regularly exposed to HIV, for example, because your partner has HIV, you can take 300 mg of tenofovir (TDF) in combination with 200 mg of emtricitabine (FTC) every day to prevent becoming infected. It may be just as effective to take the tenofovir with 300 mg of lamivudine (3TC) instead of the emtricitabine (FTC), if that is what is available.

PEP (Post-Exposure Prophylaxis)

PEP is a short course of treatment after forced or unprotected sex, or through contact with blood. Both children and adults who have been raped or abused sexually, had unsafe sex, or were stuck with a needle should seek health care and see if they can use HIV medicines to prevent infection. These medicines must be started within 3 days (72 hours) of the exposure and used for 28 days.

Medicines for Post-Exposure Prophylaxis (PEP)

It is best to take all 3 medicines, but if not all are available, taking even 2 medicines may prevent HIV.

Best combination for a child under 11 years old
HIV Ch7 Page 115-1.png

Medicine Weight of child Dose Warnings and side effects
  • zidovudine (AZT)
4 kg to less than 9 kg 12 mg per kg, 2 times a day May cause anemia.
9 kg to less than 30 kg 9 mg per kg, 2 times a day
30 kg and over 300 mg, 2 times a day
  • lamivudine (3TC) using a 150 mg tablet
14 kg to less than 20 kg ½ tablet, 2 times a day
20 kg to less than 25 kg ½ tablet in morning,
1 tablet in evening
25 kg and over 1 tablet, 2 times a day
  • lopinavir/ritonavir (LPV/r) using a 100 mg/25mg children’s tablet
15 kg to 25 kg 12 mg per kg, 2 times a day Do not crush tablets.

May cause belly pain and/or diarrhea.
over 25 kg to 35 kg 3 tablets, 2 times a day
over 35 kg to 45 kg 4 tablets, 2 times a day

Best combination for a child 11 years old or older
HIV Ch7 Page 115-1.png
Medicine Dose Warnings and side effects
  • tenofovir (TDF)
300 mg once a day May cause kidney problems.
  • emtricitabine (FTC)
200 mg once a day
  • lamivudine (3TC)
300 mg once a day
  • lopinavir/ritonavir (LPV/r)
400 mg/100 mg Do not crush tablets.
2 times a day May cause belly pain and/or diarrhea.

A person over 11 years could instead use one of the combinations in ART for treatment and prevention for people age 11 and older for 28 days if the medicines in the chart above are not available.

This page was updated:22 Jan 2020