Alfentanil

Independent Study

Continuing Nursing Education

There has been a dramatic rise in the number of individuals who are using complementary and alternative medicines, specifically herbal supplements. This can potentially have substantial affects in the perioperative patient population. While there are still limited facts and research to identify which herbal supplements may interfere with anesthesia and postoperative healing, healthcare providers in the 21 st century must be aware of the potential interactions and apply special consideration to these patients. The most crucial factor is properly identifying patients who are utilizing herbal supplements and apply current knowledge to limit the risk for complications. The risk to surgical patients caused this author to create a handout that is given during surgery scheduling to all the surgical patients within an orthopedic clinic in southeast Kansas. This article will include an explanation of the adverse reactions that are documented, as well as the potential risks that may occur with commonly used herbal supplements in the perioperative patient.

Background

In 1994 the Dietary Supplement Health and Education Act made the classification of herbal medicines the same as dietary supplements. Over-the-counter and prescription drugs must adhere to strict safety and efficacy standards to guarantee quality assurance and prevent compromised safety, but this is not required of herbal supplements (Ang-Lee, Moss & Yuan, 2001). There is limited data and research to identify drug pharmacodynamics and pharmacokinetics when there are drug-herb interactions. Most herb-drug interactions are speculative because there is lack of laboratory testing and the warnings are theorized based on the pharmacodynamics of the substances (Norred & Brinker, 2001). The majority of documented cases of interactions are difficult to identify because the patient may be taking multiple herbal supplements or prescriptive medications. This is especially true in anesthesiology when a multitude of potent drugs, with a narrow therapeutic window, are utilized for induction and maintaining general anesthesia.

In the United States a 1997 study found that 12% of the population was using herbal supplements, and this was a 380% increase from 1990 (Ang-Lee, Moss & Yuan, 2001). The majority of patients do not disclose to their healthcare provider during routine exams or during a pre-operative evaluation the use of herbal supplements. Studies have shown that patients fail to report herbal supplements usage between 20-70% of the time, and the majority are self-prescribed and not being monitored by a healthcare provider (Ang-Lee, Moss & Yuan, 2001; Norred & Brinker, 2001). The failure of patients to report this vital information prior to surgical procedures can result in inadvertent administration of contraindicated drugs. All healthcare providers must be aware of the potential usage of herbal supplements, but special attention must be directed to the preoperative patient. The pre-operative evaluation must be thorough in screening and identifying patients, by incorporating questions specific for using herbal supplements. Once herbal supplement use is identified, the healthcare provider should include the specific herb, brand, amount taken, time period taken and where purchased (Murphy, 1999). Request that the patient bring their supplements, in the original bottle, to the pre-operative evaluation (ASA, 1999). If the patient is using an herbal supplement that may pose a health risk for surgery, the surgeon and anesthesia provider should be made aware. Besides perioperative nurses, transplant nurses should also be aware of the many interactions that can interfere with their patient's surgery and recovery. The most common adverse reaction of herbal supplements is inhibition of platelet aggregation, causing increased risk of bleeding, which is important for all nurses. If your facility does not have guidelines for herbal supplements in the perioperative patient, then all identified cases should be addressed prior to surgery to establish a safety risk. Healthcare providers need to be able to explain to the patients, with validated research, the recommendations for discontinuing the herbal supplement prior to surgery and the anticipated time when it will be safe to resume it (Norred & Brinker, 2001).

While there is a potential for herbal supplements to be indicated, they must be monitored and recommended by healthcare providers who are accurately and thoroughly educated in their use. Health care providers who are not comfortable or educated in herbal therapies should refer these patients to someone who is qualified and not just condemn their use. The world of herbal supplements is not new, but the research is just now being thoroughly explored for healthcare providers to become educated on the combination of conventional and alternative medicine. Herbal Interactions and Risks

The following is a compilation of research articles (AAOS, 2001; Ang-Lee, Moss & Yuan, 2001; Norred & Brinker, 2001; ASA, 1999; Murphy, 1999; Miller, 1998) on the most frequently used herbal supplements and potential or established risks in relation to surgical patients. Because there are not clear guidelines on the proper dosing, daily recommendations and content variations in different products or brands, it is difficult to say definitively that a specific reaction will occur with all herbal supplements. The following information should be used as a guideline and understood that potential risks do exist. Healthcare providers should continue to follow this subject for further research and recommendation. Table 1 provides a sample patient handout that is given to preoperative patients in this author's practice.

Echinacea: hepatotoxicity with extended use beyond 8 weeks; should not be taken with other hepatotoxic drugs; becomes immunosuppressive after 24 weeks, which may interfere with wound healing and increase postoperative infections; should not be taken with other immunosuppressive therapies or disorders (transplant, HIV, leukemia patients, etc.); may cause nausea.

Gingko: inhibits platelet-activating factors and platelet aggregation, increasing bleeding; avoid or closely monitor with other anticoaugulants and anti-thrombolytics; may reverse monoamine oxidase inhibitors (MAOI) activity; decreases effectiveness of anticonvulsants; potentiates tricyclic antidepressants; may cause muscle cramps and spasm; documented cases of spontaneous intracranial hemorrhage and hyphema.

Ginseng: significant variations in content; false elevation in digoxin levels without digoxin toxic side effects; may cause hypoglycemia; augments corticosteroids; increases insomnia, nervousness, hypertension, vomiting, headache, tachycardia, mastalgia and epistaxis; adverse effect of vaginal bleeding and disordered proliferative endometrial biopsy patterns; inhibits platelet aggregation and is irreversible; avoid concomitant use with aspirin, heparin, warfarin and nonsteroidal anti-inflammatory drugs (NSAIDs) (both increased and decreased International Normalised Ratio [INRs] have been identified), stimulants, antihypertensives and antidepressants.

St. John's Wort: inhibits dopamine, serotonin and norephinephrine reuptake; avoid concomitant use with MAOIs and selective serotonin reuptake inhibitors (SSRIs); may lower digoxin levels; may cause photosensitivity and nausea; prolongs and intensifies the effects of general anesthetics and narcotics; increases concomitant metabolism of lidocaine, calcium channel blockers, alfentanil and midazolam; decreases the effectiveness of anticoagulants, antiviral and immunosuppressant drugs; documented cases of transplant rejection.

Valerian Root: avoid use with barbiturates; withdrawal potential similar to acute benzodiazepine withdrawal, avoid abrupt discontinuation; potentiates sedative effects of general anesthetics and general anesthetics and gamma-aminobutyric acid (GABA) receptor acting adjuvants.

Ephedra/Ma Huang: causes dysrythmias, tachycardia, hypertension, uterine contractions, toxic psychosis and vasoconstriction or vasospasms of coronary and cerebral arteries causing adverse cardiovascular events that have resulted in death; depletes catecholamine stores which can precipitate perioperative hemodynamic instability; contraindicated with general anesthetics, oxytocin, cardioglycosides, stimulants, decongestants, MAOIs and beta-blockers; rare cause of radiolucent kidney stones.

Garlic: inhibits platelet aggregation and increases bleeding; potentiates anticoagulants and other platelet inhibiting drugs; may cause hypotension; documented cases of spontaneous epidural hematomas.

Kava: potentiates the effects of alcohol, barbiturates, hypnotics, general and local anesthetics, antiepileptic drugs, muscle relaxants and benzodiazepines; may be hepatotoxic; inhibits platelet aggregation; may have addictive properties and acute withdrawal.

Ginger: may enhance bleeding, central nervous system (CNS) depression, hypotension, cardiac arrhythmias and hypoglycemia; avoid interactions with anticoagulants, barbiturates, antihypertensives, cardiac and hypoglycemic drugs.

Licorice: may cause hypertension, hypokalemia and edema; inhibits platelet aggregation.

Feverfew: interferes with clotting factors and inhibits platelet aggregation.

Goldenseal: increases fluid retention, hypertension, nausea and nervousness; counteracts effects of antihypertensives and diuretics.

References

American Academy of Orthopaedic Surgeons(AAOS). (2001). Commonly used herbal supplements, potential hazards. AAOS Bulletin, October, 20-21.

American Society of Anesthesiologist(ASA). (1999). Anesthesiologists warn: If you're taking herbal products tell your doctor before surgery. Available at: http://www.asahq.org/PublicEducation/herbal.html. Accessed: March 27, 2002. Ang-Lee, M., Moss, J. & Yuan, Chun-Su. (2001). Herbal medicines and perioperative care. Journal of the American Medical Association, 286(2), 208-216.

Miller, J. (1998). Herbal medicinals: Selected clinical considerations focusing on known or potential drug-herb interactions. Archives of Internal Medicine, 158(9), 2200-2211.

Murphy, J. (1999). Preoperative considerations with herbal medicines. American Operating Room Nurses Journal, 69(1), 173-183.

Norred, C. & Brinker, F. (2001). Potential coagulation effects of preoperative complementary and alternative medicines. Alternative Therapies, 7(6), 58-66.

By: Amy L. Hite, MSN, FNP-C, ONC

About the Author

Amy L. Hite, attended Pittsburg State University to earn her Bachelor's of Science in Nursing and her Master's of Science in Nursing / Family Nurse Practitioner. She is a member of KSNA District 20 where she is currently treasurer, in addition to

being a member of the National Orthopedic Nurses Association and the American Academy of Nurse Practitioners. She works for New Century Orthopedics and Sports Medicine, Pittsburg, as a Nurse Practitioner, as well as coordinating an osteoporosis clinic.

Copyright Kansas State Nurses Association May 2002
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