When considering the use of various medications during pregnancy the most pressing concern, and rightly so, is the risk of the medication causing birth defects or in other ways harming the pregnancy.  We would like to add the reminder, however, that there are also other matters that need to be kept in mind, not the least of which is pharmacokinetics.  There are many physiologic alterations that occur during pregnancy and changes in renal dynamics and hepatic function figure largely among them.  It is frequently the case that medication dosages need to be adjusted upward or downward during pregnancy.  This is often true of the medications used to prevent or treat malaria.  As these changes are not entirely predictable and there is considerable individual variation, we can only advise that whenever possible drug levels be monitored in pregnant women when they are taking important medications.

As we have stated in regard to vaccines, we advocate that the occurrence of pregnancy not lead to paralysis in the matter of prescribing the usual necessary medications for prevention or treatment of travel-related illness.  Our section on malaria prevention contains references regarding the disastrous effects of such neglect.

We present here the general references and sources that we have found most helpful in establish the risk:benefit ratio of the drugs we often need to use, along with some of the topics that most frequently arise for discussion.

General

1.      Briggs GG, Bodendorier TW, Freeman RK, Yaffe SJ.  Drugs in Pregnancy & Lactation.  Williams & Wilkins, Baltimore, MD

2.      De Vigan C, De Walle HE, Cordier S, Goujard J, Knill-Jones R, Ayme S, Calzolari E, Bianchi F. Therapeutic drug use during pregnancy: a comparison in four European countries.  OECM Working Group. Occupational Exposures and Congenital Anomalies. J Clin Epidemiol 1999 Oct;52(10):977-82

3.      Teratology 1994 Jun;49(6):446-7 FDA classification of drugs for teratogenic risk. Teratology Society Public Affairs Committee. The Teratology Society believes that the current FDA Use-in-Pregnancy Ratings should be abandoned. The Society recommends that drug labeling should include narrative statements that summarize and interpret available data regarding hazards of developmental toxicity and provide estimates of potential teratogenic risk.

Folate supplements

1.      National Institutes of Health.  Consensus development conference statement. Optimal calcium intake.  Bethesda, Maryland:  NIH Office of Medical Applications of Research, 1994

2.      Centers for Disease Control.  Recommendations for the use of folic acid to reduce the number of cases of spina bifida and other neural tube defects.  MMWR 1992;41(RR-14):1-7

3.      American College of Obstetricians and Gynecologists.  Folic acid for the prevention of recurrent neural tube defects.  ACOG Committee Opinion 120. Washington, DC:ACOG 1993

4.      Centers for Disease Control. Use of folic acid for prevention of spina bifida and other neural tube defects—1983-1991.  MMWR 1991;40:513-516

5.      Ortelli F, Maxwell CA, Curtis J, Watkins WM. Studies on anti-folate antimalarials in east Africa. Parassitologia 1999 Sep;41(1-3):313-4

6.      Fleming AF, Ghatoura GB, Harrison KA, Briggs ND, Dunn DT. The prevention of anaemia in pregnancy in primigravidae in the guinea savanna of Nigeria. Ann Trop Med Parasitol 1986 Apr;80(2):211-33

Water filters

1.      Goodyer  L, Behrens RH.  Safety of iodine based water sterilization for travelers.  J Travel Med 2000 Jan;7(1):38

Altitude sickness

2.      Merlob P, Litwin A, Mor N. Possible association between acetazolamide administration during pregnancy and metabolic disorders in the newborn. Eur J Obstet Gynecol Reprod Biol 1990 Apr;35(1):85-8

Cold remedies

3.      Koren G. Antihistamines are safe during the first trimester. Can Fam Physician 1997 Jan;43(1):33-4

Insect repellents

4.      McGready R, Hamilton KA, Simpson JA, Cho T, Luxemburger C, Edwards R, Looareesuwan S, White NJ, Nosten F, Lindsday SW. Safety of the Insect Repellent N, N-Diethyl-M-Toluamide (DEET) in Pregnancy. Am J Trop Med Hyg (2001) 65: 285-9. The safety of daily application of N, N-diethyl-m-toluamide (DEET) (1.7 g of DEET/day) in the second and third trimesters of pregnancy was assessed as part of a double-blind, randomized, therapeutic trial of insect repellents for the prevention of malaria in pregnancy (n = 897). No adverse neurologic, gastrointestinal, or dermatologic effects were observed for women who applied a median total dose of 214.2 g of DEET per pregnancy (range = 0-345.1 g). DEET crossed the placenta and was detected in 8% (95% confidence interval = 2.6-18.2) of cord blood samples from a randomly selected subgroup of DEET users (n = 50). No adverse effects on survival, growth, or development at birth, or at one year, were found. This is the first study to document the safety of DEET applied regularly in the second and third trimesters of pregnancy. The results suggest that the risk of DEET accumulating in the fetus is low and that DEET is safe to use in later pregnancy.