Pain-killers use in pregnancy

Acetaminophen (Paracetamol) and Aspirin in Pregnancy

Paracetamol or Acetaminophen is generally regarded to be safe at any stage of pregnancy, when taken in normal dosages.

Aspirin's case is slightly more complex. There is certainly no evidence of birth defects associated with use of normal dosage of aspirin in pregnancy. However, prolonged use has been associated with a slight increase in low birth weight and possibly even an increase in the incidence of stillbirth.

Some studies in the United States suggested that there is increase in the risk of a birth defect of the abdominal wall called gastroschisis with use of Aspirin in pregnancy. It is a defect which requires surgical correction soon after birth.

There is also the theoretical worry that the baby, especially if premature, could be at risk of bleeding complications. All this means that the use of aspirin in normal or high doses is generally to be avoided in pregnancy.

The use of low-dose aspirin at 75 or 100 mg daily is not associated with these potential problems. This dose is ineffective for pain control in an adult and is used to prevent other problems.

Other non-steroidal anti-inflammatories (NSAIDs) in pregnancy

Aspirin belongs to a class of drugs known as NSAIDs. They are quite widely used. Other familiar non-steroidal ani-inflammatories (and potent pain-killers) include Iboprufen (Brufen; Advil), Naproxen (Aleve, Naprosyn), Meloxicam (Mobic), Diclofenac (Voltarol Voltaren) and Indomethacin (Indocid). There are several others. These drugs are important because many are widely available over the counter (without prescription). They are used in chronic inflammatory conditions such as arthritis, as pain-killers and to bring down fever.

The use of NSAIDs in pregnancy is not advised particularly so in the first trimester. This is because there is evidence that their use could lead to a miscarriage. Regular NSAIDs use in pregnancy has also been associated with a serious condition called Persistent Pulmonary Hypertension of the Newborn (PPHN). This condition can be fatal.

Codeine in pregnancy

Codeine is one of the "opioid" painkillers. The most famous member of this family is morphine. On a purely fetal wellbeing consideration, these drugs are safe in the sense that they do not cause birth defects.

There are several variants of codeine such as dihydrocodeine (also called DF118) and those drugs which are combinations of codeine and other painkillers, especially Paracetamol. These combination drugs include Co-codamol, Co-dydramol, Kapake® Tylex®, Solpadol® and Codipar®.

There is no evidence of any harm as a result of using normal doses of these codeine-based drugs in pregnancy.

Safety of morphine and Pethidine in pregnancy

The presumed safety of Codeine (above) does extend to Morphine; to a degree. The problem of morphine is that it is addictive, and the dependency and severe withdrawal complications will affect the fetus or newborn likewise. For this reason, it is hard to see any justification of using it long term in pregnancy. However, its short-term use for acute pain should be no cause for concern. The advice for Pethidine use is similar.