7 Drugs that are NOT Safe during Pregnancy

Credit: www.parents.com

Drugs are marked “NOT” safe in pregnancy if they have actually caused, are suspected to have caused or may be expected to cause, an increased incidence of human foetal malformations or irreversible damage. Drugs that may also have adverse side effects (due to their mechanism of action) which may be reversible are considered unsafe.

Previously, we discussed on drugs that are safe to use during pregnancy, we want to balance the pendulum by discussing the drugs that are not safe for use during pregnancy

Please note that though these drugs may not be safe in pregnancy, an occasion may arise when they may have to be given based on the benefit/risk ratio.

However, drugs which have such a high risk of causing permanent damage to the foetus should NOT be used in pregnancy or when there is possibility of pregnancy.

Below is a list of 7 drugs considered not safe during pregnancy;



Ciprofloxacin belongs to a class of antibiotics called quinolones. There have been lots of controversies on their safety in pregnancy. Though there are no adequate and well-controlled studies in humans, studies in animals have shown evidence of adverse effect on the foetus.

Cartilage damage and arthropathy (disease of the joints) have been reported in immature animals of various species giving rise to concern over possible toxic effects on human foetal bone formation.

Because safer alternatives are generally available, it is advisable not to take ciprofloxacin in pregnancy, especially during the first trimester. The risk is not worth it, kindly stay clear!

Other common antibiotics in this class include: Levofloxacin, Ofloxacin, Sparfloxacin, etc


Prednisolone is another controversial drug. Prednisolone belongs to a class of drugs called corticosteroids. They are used to treat many conditions e.g asthma, allergic disorder, arthritis, skin conditions etc. They help to prevent or suppress swelling, irritation and immune responses.

Older studies suggested a small increased chance of oral clefts when oral corticosteroids like prednisolone are used in the first trimester. A re-evaluation of one of the studies with a larger sample size, showed a weaker association with oral clefts. Thus, the risk from first trimester exposure to prednisolone is thought to be very small.

An oral cleft happens when the lip or palate (roof of the mouth) does not fully close during development. On the other hand, a number of other human studies have not shown an increase in the chance for birth defects with first trimester exposure to oral corticosteroids.

Taking an oral corticosteroid like prednisolone long-term during pregnancy has been associated with an increased chance for delivering a baby that is premature (born before 37 weeks of pregnancy) and/or has a lower birth weight than expected.

Except it is “deadly” needed, my advice; stay clear!

Other common examples of oral corticosteroids include Prednisone, dexamethasone etc


Tetracyclines are broad spectrum antibiotics. Common examples include; Doxycycline, minocycline etc. Animal studies have revealed evidence of teratogenicity (toxic effects to the embryo and skeletal malformation).

There are no controlled data in human pregnancy, however, birth defects and maternal hepatotoxicity (toxic effects on the liver) have been reported.

When used during tooth development (second half of pregnancy), tetracyclines may cause permanent yellow-gray-brown discoloration of the teeth and enamel hypoplasia.

The use of tetracycline during pregnancy is generally not recommended, especially during the last half of pregnancy.


They are used to treat variety of parasitic infections. Animal studies have revealed evidence of teratogenicity (embryotoxicity and skeletal malformations) in pregnant rats and rabbits. Although no controlled data in human pregnancy, these drugs should not be used in pregnant women except in clinical circumstances where no alternative management is appropriate. Patients should avoid pregnancy until at least 1 month after stopping therapy.

If a patient becomes pregnant while taking this drug, it should be discontinued immediately.


Fluconazole is used to treat fungi infections. Several epidemiologic studies do not indicate an increased risk of birth defects associated with low-dose exposure during pregnancy (single 150 mg oral dose). Data from several hundred pregnant women treated with standard doses (less than 200 mg/day), as a single or repeated dose in the first trimester, show no adverse foetal effects.

High-dose animal studies have revealed evidence of teratogenicity (lethal/toxic effect on the embryo/foetus) though no controlled data in human pregnancy.

A few cases of birth defects have been reported in infants exposed in utero to high-dose maternal fluconazole (400 to 800 mg/day) during most or all of the first trimester. Brachycephaly, abnormal facies, abnormal calvarial development, cleft palate, femoral bowing, thin ribs and long bones, arthrogryposis, and congenital heart disease have been observed in these infants.

Standard doses and short-term therapies are not recommended unless clearly needed; Pregnant women having candida infections should consider using antifungal pessary formulations (vaginal insert; reduces exposure of foetus to the drug).

High-dose and/or prolonged regimens should not be used during pregnancy, except for potentially life-threatening infections.


Ibuprofen belongs to the class of pain reliever medications called non-steroidal anti-inflammatory drugs (NSAIDs). They work by inhibit prostaglandins, hormone-like substances that modulates inflammation in the body amongst other functions. Animal studies have revealed evidence of increased risk of miscarriage, cardiac malformation, and gastroschisis following use of prostaglandin synthesis inhibitors in early pregnancy.

Administration of nonsteroidal anti-inflammatory drugs (NSAIDs) during the third trimester of pregnancy may cause significant adverse effects, including premature closure of the foetal ductus arteriosus, oligohydramnios, foetal renal impairment, and pulmonary hypertension. There are no controlled data in human pregnancy. Administration during labour and delivery is not recommended; onset of labour may be delayed and duration increased with greater bleeding tendency in mother and child.

Other common examples of NSAIDs include; naproxen, ketoprofen, diclofenac, acyclofenac etc


Animal studies do not indicate harmful effects with respect to pregnancy, embryo or fetal development, birth or postnatal development. However, because there are no adequate and well-controlled studies in pregnant women, it is marked not safe (probability of having harmful effects on the foetus though may not cause malformation).These effects may be reversible. This drug should be used during pregnancy only if clearly needed. Insulin is an established safe alternative.

Always consult your doctor or pharmacist before taking any medication, especially during pregnancy.

I also want you to follow me on my social media handle to ask me any question that borders you. Your baby is your future.


EMDEX Vol 1: June 2016 – May 2017 Edition

The Merck Manual of Diagnosis and , Nineteenth Edition

https://www.drugs.com/pregnancy Accessed 19/08/16

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