Painkillers in Pregnancy
Pain can be a major and intractable problem in pregnancy. This could be in the form of lower backache, lower abdominal pain, headache or pain in the lower limbs. What about the use of painkillers?
Paracetamol (Acetaminophen in North America) 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. 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.
This is one of the "opioid" painkillers. The most famous member of this family is morphine. On a purely fetal wellbeing consideration, these drugs have always been regarded as safe. However, in a large study published in the American Journal of Obstetrics and Gynecology in February 2011, the use of opioid pain-killers in early pregnancy has been associated with an increased risk of congenital heart defects. Caution at this phase of the pregnancy is therefore called for.
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®.
Does the presumed safety of codeine in pregnancy extend to morphine?
Yes, 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.
Constipation is another common problem in pregnancy. What about medicine used to relieve this?
Any doctor or midwife confronted with this problem should first and foremost proffer a dietary solution. This does help in a lot of cases, though not all. High fibre and fresh fruit should be prominent in the diet. It is only when this does not work that drug preparations should be considered.
Lactulose is known to be safe in pregnancy. It is contraindicated in people with the rare condition known as galactosaemia (the body's inability to change galactose, a sugar derived from milk sugar, into glucose). It is probably vital for the mother to know that lactulose is not absorbed from the gut and therefore has no chance of reaching the baby.
Fybogel® (isphagula) is one of a group of "bulk-forming laxatives". These need to be taken with plenty of fluids. Other preparations of a similar compound come with names such as Regulan®, Fibrelief®, Isogel® and Konsyl®. Also related are bran and Sterculia (Normacol®) etc.
All these are safe as they do not stimulate the uterus and are not absorbed from the gut and therefore do not reach the fetus.