HeadWise Volume 3, Issue 3 | Page 14

to control other vascular risk factors, such as high blood pressure, elevated cholesterol, and smoking. In general, we ask patients to carefully evaluate their lifestyle. Nutrition, hydration, exercise, and sleep are factors which need to be considered. We also ask the patients to recognize stressful situations and consider use of stress relaxation, meditation, yoga, or massage. Adequate sleep, attention to sleep hygiene, and stress relaxation also becomes paramount. During pregnancy, we advise our patients about the one-third rule. A third of the pregnant migraineurs improve during pregnancy, one-third maintains the status quo, and the remaining one-third experience an exacerbation of their headaches. Very rarely, migraines develop for the first time during pregnancy. In general, patients with menstrually-associated migraine improve during pregnancy. It is believed that hormonal fluctuations are probably the main trigger for migraine. Migraine Treatment During Pregnancy Three classifications for drug safety during pregnancy have been established. The U.S. Food and Drug Administration (FDA) categorizes the drugs into Category A through X (Table 1), Classifications have also been developed in Sweden and Australia. There is one additional category, “Pregnancy Category N”, which is a transitional identification indicating that the FDA has not yet classified the drug into a specified pregnancy category. Acute Treatment Recently, a large observational prospective study was conducted in Norway involving pregnant women. In the Norwegian Mother and Child Cohort Study, 1535 pregnant women received triptans. This study does provide some reassurance to women who may need to continue to use triptans during pregnancy. These women were compared to 373 migraine controls who had used a triptan during the 6 months prior to pregnancy. During the first trimester, 90% of the approximately 1400 patients used a triptan. In this relatively large cohort of pregnant patients exposed to the triptans during their first trimester, no increased risk of malformations in the fetuses was observed. A pregnancy exposure registry is a study that collects health information from women who take medicines or vaccines while they are pregnant. The FDA does not run pregnancy studies, but it keeps a list of all registries that are current. Most pregnancy registries are sponsored 14 HeadWise™ | Volume 3, Issue 3 • 2013 by pharmaceutical companies, and maintained by an independent research company. In general, we consult with a perinatologist and if available, a pregnancy toxicologist, in order to consider other risk factors such as maternal age, health, smoking, alcohol or other drug use, to assist in decisions of whether or not to continue the use of triptans during pregnancy. Probably, sumatriptan has the largest pregnancy registry. If a triptan is deemed low risk, we tend to recommend it over those with higher risk to the fetus. The largest available data on opiates and pregnancy are based on retrospective exposure studies from the National Birth Defects Registry (NBDR). In these studies, data on over 17,000 cases were examined, with over 6000 controls, excluding mothers with exposure to street drugs, preexisting diabetes, or malformations with less than 200 cases or <4 exposures. Of the mothers interviewed, 2.6% reported use of opiates during the month prior or 3 months into their pregnancy, while 2.0% of controls reported a similar exposure. The predominant opiate exposures were to codeine and hydrocodone (34.5% each). A significant association was found between opiate use and congenital heart defects, as well as spina bifida, hydrocephaly, glaucoma or anterior chamber eye defects, and gastroschisis. Gastroschisis is a congenital defect characterized by a defect in the anterior abdominal wall through which the abdominal contents freely protrude. It is usually to the right of the umbilicus (belly button). Finally, maternal obesity is another factor that needs to be considered. Maternal obesity has been associated, in and of itself, with increased risk of neural-tube defects and congenital heart defects. A neural tube defect (NTD) is an opening in the spinal cord or brain that occurs very early in human development and fails to close. Unfortunately, few studies have examined the effect modification based on obesity, which may be due to the pharmacokinetics of many of the medications. The term, pharmacokinetics, describes what happens in the body once a drug is administered. This includes the mechanisms of absorption and distribution, as well as the chemical changes (metabolism) of the substance in the body and how it is excreted from the body. Pregnancy Planning in the Migraineur: Preventive Therapy The biggest concern with preventive medication use during pregnancy is the risk of congenital malformations.