Are any drugs not recommended in pregnancy?

Efavirenz is not usually recommended in pregnancy.

This drug caused neural tube (the developing brain) damage in the developing foetus in a single animal study. It is important to note though that efavirenz is the only ARV that has ever been tested in this way.

So far there are no reports of a similar increased risk in human babies. As more women become pregnant when they are already taking HAART, there have been more cases of women receiving efavirenz at this time.

For example in a British study of women receiving HAART at conception, 20 percent of women receiving an NNRTI received efavirenz.

There have been many more reports of women receiving efavirenz in pregnancy throughout the world that offer reassurance to mothers and doctors.

But, if other treatment options are available, there is a caution against its use. This is considered to be 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 foetoprotein 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.

The liquid formulation of amprenavir, a less commonly used protease inhibitor, is also not recommended in pregnancy (or for children under four). This is because pregnant women and young children are unable to break down one of its components called propylene glycol. The capsule form of amprenavir does not contain propylene glycol.

ddI is not recommended in pregnancy. There may be a small increased risk of birth defects with this drug. Also there is a mild possible increase with nelfinavir. These drugs are rarely used in the UK now.

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

d4T (stavudine) is no longer recommended in the UK, except as a last resort.

And, as we described earlier, nevirapine is not recommended for women with higher CD4 counts (above 250).