HIV drugs during pregnancy

Which drugs should I use?
Using triple combinations
Are any drugs not recommended in pregnancy?

Which drugs should I use?

Like all decisions relating to HIV treatment, there are no hard and fast rules.

Your treatment should be individual.
It should suit your own health and your own situation.

Using triple combinations

CD4 count, resistance, viral load and other words and phrases explained.

If you are already using combination therapy, you are likely to remain on the same combination.
If you do not need to use treatment for your own health, you may decide to use START.

Pill bottle It is likely you will be recommended to use AZT as part of your combination.

This is because AZT is still the only HIV drug licensed for use in pregnancy. You should have a resistance test to confirm whether AZT is active against your own HIV. This test will help decide which other drugs you need to use.

You will probably be recommended to use AZT plus 3TC as two of the drugs as there is a lot of safety data on them regarding pregnancy.

However, because 3TC resistance develops very easily it you should not just use these two drugs alone. You should use them with another HIV drug in a triple combination.

This third drug will probably be a protease inhibitor. Again, the resistance test will help ensure that you choose drugs that will work.

The protease inhibitor is likely to be be saquinavir boosted with ritonavir, lopinavir boosted with ritonavir (called Kaletra and in one pill) or atazanavir boosted with ritonavir.

If you plan to stop treatment straight after your baby is born a protease inhibitor has another advantage. You body processes protease inhibitors relatively quickly. If you are taking it with AZT and 3TC, you can stop all your treatments at the same time with a low risk of resistance.

Another drug that is often used is an NNRTI called nevirapine, which is a drug that has been widely used in pregnancy.

There is a caution against the use of nevirapine for women with CD4 counts above 250 cells/mm³ because of a risk of liver (hepatic) toxicity. Pregnant women are perhaps more likely to match this description than non-pregnant women, especially if choosing short course therapy.

Nevirapine appears to be safe for women with lower CD4 counts (below 250 cells/mm³). There is no concern with people who have used nevirapine successfully in their combination and gained a higher CD4 count on treatment.

You will probably receive nevirapine if you start your treatment with a CD4 count less than 250 cells/mm³.

If you are using efavirenz, ddI or ddI and d4T together, you may need to stop or switch those drugs. This will also depend on what other choices are available to you.

If you have side effects, or your viral load is detectable, your doctor will also look for a possible switch in therapy.

Although it is rare, some women have even delivered babies on combinations of five or more anti-HIV drugs (sometimes called mega-HAART).

Finally, if you only find out that you are HIV-positive very late into your pregnancy or in labour you will have specific treatment. Depending on your CD4 count you are likely to be offered nevirapine. This drug is absorbed very rapidly and is the most effective drug for reducing mother-to-child transmission in this situation.

As resistance to nevirapine develops easily, you need to use it with two other drugs. These are often AZT and 3TC (called Combivir, when together in one pill).

It is best to continue with this combination until your viral load is below 50 copies/mL. This will reduce the risk of resistance.

If you choose to stop treatment after this, you will need to stop the nevirapine before the other two drugs. It may also be a good idea though to stay on treatment until you and your doctor have a clearer picture of your own health and treatment needs.

You should only continue treatment if you are strictly taking every dose as prescribed.

In some circumstances, depending on the drugs you are using and your birth plan, you may also receive AZT intravenously (IV) during labour.

Mono and dual therapy

Monotherapy is using only one HIV drug and dual therapy uses two drugs. Neither strategy has been as effective as using 3 drugs for treating HIV. In some circumstances though, these strategies are still recommended for reducing mother-to-baby transmission.

Are any drugs not recommended in pregnancy?

Efavirenz

Efavirenz is not recommended in pregnancy. This drug caused neural tube defects (brain damage) in the developing foetus in a single animal study.

So far there are no reports of increased risk of neural tube damage in human babies. But, if other treatment options are available, there is a strong caution against its use.

This is most important during the first 12 weeks of pregnancy when the neural tube is developing.

If you are already 12 or more weeks pregnant and have been taking efavirenz during this time you will need two tests.

Firstly, it is important that you receive early ultrasound evaluation.
You will also have another test called maternal alpha fetoprotein test. This is a screening test for neural tube defects.

After the first trimester, there may be no point in stopping efavirenz if you are doing well on it. Sometimes it may even be a good option to use after a late diagnosis if you have a higher CD4 and nevirapine is not recommended.

ddI

ddI is not recommended in pregnancy as there is an increased risk of birth defects with this drug.

ddI and d4T

There is also a strong warning to avoid using the drugs ddI and d4T together in pregnancy. There have been several reports of fatal side effects in pregnant women using both these drugs together.

d4T is no longer recommended for first-line therapy in the UK guidelines.

Nevirapine

As we described earlier, nevirapine is not recommended for women with higher CD4 counts (above 250/mm³).

Safety data

Safety data means information that a drug has been used safely in a certain number of people. Generally the more information we have on use of a drug in a large number of people, the more confidant we can be that it is safe to use in that population.