Many common medicines are safe in pregnancy, but some can harm a developing baby, especially in the first three months. The tricky part is that many women take medicines in the first month before they know they are pregnant. This guide lists the main drugs to avoid in pregnancy, explains why, and tells you what to do if you have already taken one.
Important: If you take a regular medicine for a long-term condition such as epilepsy, high blood pressure, sickle cell disease or HIV, do not stop it suddenly. Some conditions are more dangerous to your baby when untreated. Speak to your doctor first, ideally before you get pregnant.
Your baby’s major organs, including the heart, brain, spine and limbs, form between about weeks 3 and 10 of pregnancy. This is when some medicines are most likely to cause birth defects. Later in pregnancy, certain drugs can affect your baby’s growth, kidneys, heart or the amount of amniotic fluid.
These three medicines are so harmful to a developing baby that they are best stopped before you even try to conceive. If you take any of them and are planning a pregnancy, or think you could become pregnant, talk to your doctor now so they can plan when to stop and how to manage your condition safely.
1. Isotretinoin and other retinoids
Isotretinoin (used for severe acne) and other oral retinoids cause serious birth defects affecting the face, heart and brain, as well as miscarriage. They must not be taken in pregnancy or while trying to conceive. Avoid retinoid skin creams such as tretinoin and adapalene too, and do not take high-dose vitamin A supplements.
2. Methotrexate
Methotrexate is used for rheumatoid arthritis, psoriasis, some other autoimmune conditions and some cancers. It is a strong cause of birth defects and miscarriage. It should be stopped before pregnancy, not once you find out you are pregnant, so plan ahead with your doctor if you take it.
3. Hydroxyurea
Hydroxyurea (hydroxycarbamide) is widely used in Nigeria to manage sickle cell disease. It may harm a developing baby, so if you take it and want to get pregnant, speak to your haematologist before trying to conceive. They can plan how to stop it and keep your sickle cell well controlled during pregnancy. Do not stop it on your own.
4. Ibuprofen, diclofenac and other NSAIDs
Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, diclofenac, naproxen and high-dose aspirin, are common painkillers. From about 20 weeks of pregnancy they can affect your baby’s kidneys and lower the amount of amniotic fluid, and in the third trimester they can cause a blood vessel in the baby’s heart to close too early. Avoid them unless your doctor specifically prescribes one.
Note: Your doctor may prescribe low-dose aspirin to lower the risk of pre-eclampsia. That is different from taking aspirin for pain, so keep taking it if prescribed.
What to take instead: Paracetamol is not an NSAID and is generally considered the safest painkiller in pregnancy. Use the lowest dose that works, for the shortest time, and ask your doctor if you need it for more than a few days.
5. ACE inhibitors and ARBs (some blood pressure drugs)
Lisinopril, enalapril, ramipril, losartan and similar drugs can damage the baby’s kidneys and cause low amniotic fluid, particularly in the second and third trimesters. If you have high blood pressure, your doctor will switch you to a pregnancy-safe option such as methyldopa, labetalol or nifedipine. Read more about hypertension.
6. Epilepsy and mood-stabilising medicines
Several medicines used for epilepsy and other conditions can cause birth defects or developmental problems:
If you take any of these, talk to your doctor before trying to get pregnant. Do not stop them on your own: uncontrolled seizures or mood episodes can also harm you and your baby, and your doctor may be able to switch you to a safer option.
7. Tetracycline antibiotics
Tetracycline, doxycycline and similar antibiotics can permanently stain your baby’s teeth and affect bone growth, especially after about 15 weeks. Your doctor can prescribe a safer antibiotic.
8. Some other antibiotics
Ciprofloxacin and other fluoroquinolones are usually avoided in pregnancy. Co-trimoxazole (Septrin) is also normally avoided throughout pregnancy because it interferes with folic acid. However, some people, such as those living with HIV, need Septrin to prevent serious infections. If you have been prescribed it, do not stop without speaking to your doctor. Many antibiotics, such as amoxicillin, are considered safe, so never refuse treatment for an infection; ask your doctor which one is right.
9. Warfarin
This blood thinner can cause birth defects, especially between weeks 6 and 12, and bleeding later in pregnancy. Women who need a blood thinner are usually switched to heparin injections.
10. Misoprostol
Misoprostol (sold as Cytotec) causes the womb to contract and can cause miscarriage or birth defects. It should only be used in pregnancy under direct medical supervision.
11. Statins
Cholesterol-lowering statins are usually stopped when you are planning a pregnancy or as soon as it is confirmed. They are less dangerous than the medicines above, but there is little benefit to continuing them during pregnancy. Your doctor will advise you.
12. Codeine, tramadol and other strong painkillers
Regular use, especially late in pregnancy, can cause breathing problems and withdrawal symptoms in the newborn. Only use them if prescribed.
13. Herbal mixtures and agbo
Herbal remedies are not regulated like medicines, and their ingredients and strength are often unknown. Some can trigger contractions or harm the baby’s liver and kidneys. Avoid them unless your doctor approves.
A reminder: If you take any medicine on this list regularly, for any reason, discuss it with your doctor before stopping. But if you are pregnant and feel unwell, do not diagnose yourself and buy medicines at the pharmacy. Self-treating is a bad idea at any stage of pregnancy. See a doctor or pharmacist first and tell them you are pregnant.
Many medicines are safe when used as directed. These include paracetamol for pain or fever, most antacids for heartburn, and the routine supplements your clinic gives you. For malaria, your doctor will choose a treatment that is safe for your stage of pregnancy. Never assume a medicine is safe because it is sold over the counter: always check with a doctor or pharmacist first.
See routine drugs for pregnancy for the supplements you should be taking.
Which medicines should I stop before getting pregnant?
Isotretinoin, methotrexate and hydroxyurea are best stopped before you try to conceive, with your doctor’s guidance. If you take valproate, phenytoin, carbamazepine, lithium or warfarin, speak to your doctor before trying for a baby so they can review your treatment.
What medicines should I avoid in the first month of pregnancy?
Avoid the medicines listed above, along with high-dose vitamin A, and check any other medicine with a doctor or pharmacist before taking it. Keep taking folic acid.
Is paracetamol safe in pregnancy?
Yes, paracetamol is generally considered safe when taken at the recommended dose for short periods. Ask your doctor if you need it regularly.
Can I take ibuprofen while pregnant?
It is best avoided, especially from 20 weeks onwards, unless your doctor prescribes it.
Can I take malaria drugs while pregnant?
Yes, but only those your doctor prescribes. Malaria is dangerous in pregnancy and must be treated promptly with a pregnancy-safe medicine.
More on staying healthy in pregnancy: the do’s and don’ts in pregnancy and why antenatal care matters.
Planning ahead? Find out whether HMO plans cover pregnancy and childbirth in Nigeria and the best HMO plans for families.
This article is for general information and does not replace advice from your doctor or pharmacist.
