The pattern of use was similar whether or not the parturient considered herbal remedies to be medications (P = 0.7). The pattern of discontinuation with confirmation of pregnancy, however, was more likely, approaching statistical significance (P = 0.06), if the parturient believed they were medications. The most common reasons cited for stopping medications during pregnancy were concerns regarding potential fetal risks and recommendations by an obstetrician. There was a trend toward increased herbal medicine use among women planning natural childbirth compared with those who did not (10.1% versus 6.3%, P = 0.1). Women planning to receive epidural analgesia were no more likely to take herbal preparations than were those who were planning no analgesia (7.4% versus 8.6%, NS).
Alternative medicine use and expenditures have increased steadily, with certain alternative therapies now being included in some insurance plans (1). In response, US medical schools are starting courses in CAM (11,12) and many medical associations, including the ASA (13,14), have developed pamphlets regarding the use of such remedies in the perioperative period. Although some publications have suggested the discontinuation of all herbal medicines two weeks before surgery (15), a more targeted approach based on pharmacokinetic data of active compounds has been recently suggested (16). However, as herbal medicines are considered “dietary supplements” by the Dietary Supplement Health Education Act (17), they are neither governed by federal regulations that establish criteria for purity, identification, and manufacturing, nor are they subject to the same adverse reporting rules of the Food and Drug Administration (18). As “dietary supplements,” these remedies cannot claim to cure or treat disease, but they can be marketed for certain “conditions.” Of specific concern during pregnancy is that some remedies are being marketed for such “conditions” as nausea and vomiting (19), despite limited evidence to support their efficacy (20). For example, a review of 10 studies assessing the effects of alternative therapies on first trimester nausea and vomiting included only one small trial evaluating an herbal remedy, ginger (20).
Our principal finding was that parturient use of herbal remedies, in a tertiary care teaching and private hospital, is infrequent. Our population consists largely of healthy parturients with only 7.1% reporting the use of herbal remedies, and this incidence was significantly less than the 22% observed in the general presurgical population at the same institution (3). With the growing popularity of herbal preparations, however, an increased incidence will most likely be observed. This is particularly true because few parturients consider these remedies to be medications and many obstetric providers, particularly CNMs, are encouraging their use (4). In part, this encouragement stems from isolated reports suggesting the use of herbal remedies for assisting breech version attempts, arresting premature labor, augmenting cervical ripening and labor, and for providing analgesia during labor (21,22). Commonly used herbal preparations for labor stimulation included blue cohosh, black cohosh, red raspberry leaf, castor oil, and evening primrose oil (22). Finally, more older parturients may be expected because of the increased use of in vitro fertilization therapies, and this population is more likely to use herbal remedies, as has been demonstrated in our study and previously (1,3). The small number of parturients younger than 20 years old and older than 40 years may be part of the reason that our present results regarding age did not reach statistical significance.
Multiple drug-herb interactions have been described and may result in untoward effects. Feverfew has been shown to inhibit platelet activity, garlic has been associated with decreased platelet aggregation, ginger is a potent inhibitor of thromboxane synthetase, gingko is a potent inhibitor of platelet-activating factor, and ginseng has an antiplatelet component (5). Therefore, feverfew, garlic, gingko, ginger, or ginseng alone may alter bleeding time, should not be used concomitantly with other medications that affect coagulation, and caution should be used when considering regional analgesia (5). Of note, a spontaneous epidural hematoma reported in an 87-year-old man is believed to be associated with significant amounts of ingested garlic (6). Hypericum perforatum, commonly referred to as St. John’s wort, is one of the more commonly used herbal medicines in presurgical patients (3.3%) and in parturients (1.4%). Containing different quantities of at least 10 constituents in different formulations, the purported mechanism of action is via a selective serotonin reuptake inhibition or monoamine oxidase inhibition. The coadministration of St. John’s wort and meperidine, one of the most commonly used labor analgesics, could potentially result in hyperthermia, hypertension, hypotension, rigidity, seizures, and coma (23). In addition, in the presence of St. John’s wort, physician-administered ephedrine given to treat hypotension, may have an accentuated response because of more neurotransmitter available for release (23). However, the degree of monoamine oxidase inhibition and serotonin reuptake inhibition may eventually be found not to have clinically significant interactions. Other complications from herbal preparations include precipitous labor, tetanic uterine contractions, nausea, and vomiting (22).
Limitations in our questionnaire-based evaluation of herbal remedy use may include differences in response rate, disclosure rate, recall bias, and obstetric care preferences. Our results may have underrepresented the actual number of herbal remedy users, as in the general population <40% of patients disclose the use of CAM to their physicians (1). In addition, parturients may not remember or even know what herbal remedies they were taking, especially if more than one remedy is present in a specific preparation. For example, 7% of herbal remedies in California retail herbal stores contained undeclared pharmaceuticals, with ephedrine being among the most common undeclared ingredients (7). Moreover, some parturients hoping to receive our services may have denied current use of remedies in hopes of not presenting a contraindication to regional analgesia. However, those more interested in herbs may have been more prone to fill out our survey. In addition, although we did not differentiate between obstetric care providers, at our own institution often both obstetricians and CNMs care for a parturient. Although we did not discriminate how often remedies were taken (single versus regular use in pregnancy) or started (before or during pregnancy), the question of quantity and duration of use of herbal remedies remains unknown. Until a causal relationship between use and effect is more clearly established, even a single use may be detrimental for the parturient and/or fetus. Finally, although our response rate was only 61%, our hospital is a tertiary referral center and a portion of our parturients present as transfers from outside institutions with complex medical and fetal issues. It was our policy not to approach high-risk parturients or parturients with fetal anomalies with our survey. With the event of birth, some parturients elected not to complete the questionnaire. We consider this unavoidable because of the special nature of this life event. However, these omissions could theoretically have biased our results.
In summary, our results are in agreement with prior studies (1,3) that reported an increased use of herbal medications in the fifth decade of life, even though only a small number of parturients were in this age group. Health care providers recommended these therapies even during pregnancy, and the vast majority of parturients did not consider these herbal remedies to be medications. Therefore, it is reasonable to expect an increase in the use of herbal medications in parturients. At present, there are no data that address whether to stop these remedies before surgery or labor and delivery, when to stop them, or if there is an increased maternal or fetal morbidity and mortality associated with their use. Anesthesia providers should ask routinely about their use during the preanesthesia consultation, be familiar with their side effects and drug interactions, and play a leading role in conducting clinical trials that address the use and potential interactions of CAM during the peripartum period.
The authors thank Eleanor R. Menzin, MD for the idea that led to the conduction of this study, for her insightful comments and suggestions, and for a careful review of the manuscript.
1. Eisenberg DM, Davis RB, Ettner SL, et al. Trends in alternative medicine use in the United States, 1990–1997. JAMA 1998; 280: 1569–75.
2. Blumenthal M. Interactions between herbs and conventional drugs: introductory considerations. Herbal Gram 2000; 49: 52–63.
3. Tsen LC, Segal S, Pothier M, Bader AM. Alternative medicine use in presurgical patients. Anesthesiology 2000; 93: 148–51.
4. Allaire AD, Moos M-K, Wells SR. Complementary and alternative medicine in pregnancy: a survey of North Carolina certified nurse-midwives. Obstet Gynecol 2000; 95: 19–23.
5. Miller LG. Herbal medicinals: Selected clinical considerations focusing on known or potential drug-herb interactions. Arch Intern Med 1998; 158: 2200–11.
6. Rose KD, Croissant PD, Parliament CF, Levin MP. Spontaneous spinal epidural hematoma with associated platelet dysfunction from excessive garlic ingestion: a case report. Neurosurgery 1990; 26: 880–2.
7. Ko R. Adulterants in Asian patent medicine [letter]. N Engl J Med 1998; 339: 847.
8. Angell M, Kassirer JP. Alternative medicine-the risks of untested and unregulated remedies. N Engl J Med 1998; 339: 839–41.
9. Fischer-Rasmussen W, Kjaer SK, Dahl C, Asping U. Ginger treatment of hyperemesis gravidarum. Eur J Obstet Gynecol Reprod Biol 1991; 38: 19–24.
10. Backon J. Ginger in preventing nausea and vomiting of pregnancy: a caveat due to its thromboxane synthetase activity and effect on testosterone binding. Eur J Obstet Gynecol Reprod Biol 1991; 42: 163–4.
11. Eisenberg DM. Advising patients who seek alternative medical therapies. Ann Intern Med 1997; 127: 61–9.
12. Wetzel MS, Eisenberg DM, Kaptchuk TJ. Courses involving complementary and alternative medicine at US medical schools. JAMA 1998; 280: 784–7.
16. Ang-Lee MK, Moss J, Yuan C-S. Herbal medicines and perioperative care. JAMA 2001; 286: 208–16.
18. Slifman NR, Obermeyer W, Aloi BK, et al. Brief report: contamination of botanical dietary supplements by digitalis lanata. N Engl J Med 1998; 339: 806–11.
19. Landrigan PJ, Wolfe S, Oakley GP. Bad policy, worse medicine. Pediatrics 2000; 106: 1482–3.
20. Murphy PA. Alternative therapies for nausea and vomiting of pregnancy. Obstet Gynecol 1998; 91: 149–55.
21. Chez RA, Jonas WB. Complementary and alternative medicine. Part I: clinical studies in obstetrics. Obstet Gynecol Surv 1997; 52: 704–8.
22. McFarlin BL, Gibson MH, O’Rear J, Harman P. A national survey of herbal preparation use by nurse-midwives for labor stimulation. J Nurse Midwifery 1999; 44: 205–16.
© 2002 International Anesthesia Research Society
23. Wells DG, Bjorksten AR. Monoamine oxidase inhibitors revisited. Can J Anaesth 1989; 36: 64–74.