CONSIDERATIONS IN EMERGENCY MEDICAL SERVICES
THE E. R. AND THE ISSUE OF DRUG INTERACTIONS
By Susan Taney, NP

Numerous Studies done in the US and in Europe show that the number of medications that someone is taking prior to presenting to an Emergency Room for care was the best predictor of adverse drug reactions occurring with medications administered or prescribed during the ER visit. Considering all of the types of unwanted medication reactions, neither age nor chronic poor health alone correlated as highly as being on one or more prescribed and/or nonprescribed substances (1). Data also confirms that a visit to an E.R is likely to result in the administration or prescribing of at least one medication (2).

Over the last decade there has been a rise in the incidence of adverse reactions as a result of interactions of prescription medications with dietary supplements, particularly botanicals also known as herbals. Calls to poison control centers reporting unwanted events after taking a dietary supplement have risen from about 6000 at the end of the 90's to about 14,000 a few years later (3). Although this still represents a fraction of 1% of the overall use of supplements and dwarfs in comparison to the number per year of adverse reactions to pharmaceuticals, it is of concern. Some of these potential adverse reaction cases involved an interaction between herbals as well as interactions between herbals and prescription and over the counter drugs.

With the increased use of supplements, particularly the highly chemically active herbals, there is an increased risk for adverse reactions with medications used in emergency situations. This problem is compounded by the fact that many people do not disclose to conventional health care providers such as emergency doctors and nurses their use of these products. The two common reasons for this are:

  • Not considering vitamins, minerals, herbs and other supplements as having a drug interaction potential, the belief that if it's "natural" it's safe.
  • Fear of dismissal or criticism from the conventional health care provider.

Not thinking it important or choosing not to disclose dietary supplement use adds to the risk of adverse drug reactions in emergency health care.

Although, unfortunately, there is a lack of research in the area of supplement - herb - drug interactions, there are some clinical trials underway and more pharmacological data is becoming available. Armed with more information, E.R. docs can choose medications in a way that reduces the risk of adverse reactions and are able to be alert to the occurrence of drug interactions when the potential exists (4). For this reason it is important to tell all health care providers not only what prescribed drugs are being taken but also all the over the counter drugs and dietary supplements. Make a list. This is nicely done and easily updated as a spreadsheet either with pencil on paper or on the computer. Include:

  • The name of the drug or supplement.
  • The brand name/ manufacturer
  • The dose/amount listed to be in each tablet, capsule or drop or other liquid measure (i.e. teaspoon).
  • The amount taken each time.
  • How many times a day that amount is taken.

Date each entry with a start date. If something is discontinued, put a stop date down and leave it there for a few months. Carry a copy of this with you at all times.

Addendum:

The medications administered or prescribed in E.R.'s that accounted for most of the added to multiple drug/herb combination interactions are: (5,6)

  • Warfarin (i.e. Coumadin)
  • Theophylline
  • Phenytoin
  • Macrolid Antibiotics
  • Digitalis Glycosides
  • Non Steroidal Anti Inflammatory Drugs (i.e. Ibuprophen, Naprosyn; prescribed and over the counter)
  • Angiotensin Converting Enzyme Inhibitors - ACE inhibitors
  • Calcium Channel Blockers (i.e. Verapamil)

References:

(1) Heininger-Rothbucher, D., Bischinger, S., Ulmer, H., Penchaler, C. Speer, G., Wiedermann, C. J. Incidence and Risk of Potential Adverse Drug Interactions in the Emergecy Room. Resuscitation 49 2001; 283-288.

(2) Chin, M.H., Wang, L.C., Jin, L., Mulliken, R., Hayley, D.C., et al. Appropriateness of Medication Selection for Older Persons in an Urban Academic Emergency Department. Acad Emerg Med 1999;6:1232-42.

(3) Beers,M.H., Storrie, M., Lee,G., Potential Adverse Drug Interactions in the Emergency Room. An Issue of Quality Care. Ann Inter Med 1990;112:61-4.

(4) Herr, R.D., Caravati, E.M., Tyler, L.S., Iorg, E.,Linscott, M.S. Prosperctive Evaluation of Adverse Drug Interactions in the Emergency Department. Ann Emerg Med 1992;21:1331-6.

(5) Goldberg, R.M., Mabee, J., Chan, L., Wong, S. Drug-Drug and Drug-Disease Interactions In The ED: Analysis of a High-Risk Population. Am J Emerg Med 1996; 14:447-50.

(6) Hanncoock, D., Kennington, J.M., Becker, R.R. Guide to Emergency Department Medication and Drug Interaction Evaluation. Hosp Pharm;1992:27:129-32.


Addendum #2:
Medication Errors Commonly Occur at Hospital Admission

A study looking for a variety of medication errors was done reviewing the medical records of 523 consecutive patients admitted to a general internal medicine teaching unit in a university affiliated hospital in Toronto over a three month period of time. The study was done and reported by Cornish, P. L., Knowles, S. R., Marchesano, R. et al. The results were published in the ARCHIVES OF INTERNAL MEDICINE.

Inclusion criteria included being able to communicate or having a caregiver communicate for the patient and having at least four regularly prescribed medications. The average age was 77 and 58.9% of the participants were women. Of the 523 reviewed, 151 met the criteria. Most were admitted from or through the emergency department. Medication errors were most likely to be initiated at time of admission to the inpatient unit. During their hospital stay, nearly 54% had at least one discrepancy, defined as the difference between the medication use history and the admission medication orders. The most common error was the omission of a regularly used medication acconting for 46.4% of the errors. Other discrepancies included different dose, frequency of administration or different drug. 5.7% of the errors were deemed to have a severe adverse reaction potential. One case of a patient prescribed the wrong drug occurred because the bottle that contained her pills was actually the bottle originally used for a prescription drug taken by her husband. In another case the patient continued to take his home RX and was administered the same by hospital nurses as ordered by the attending physician. He had a few days of double doses.

Cornish, P. L., Knowles, S. R., Marchesano, R. et al. Unintended medication discrepancies at the time of hospital admission. ARCH INTERN MED. 2005;165:424-429.

Commentary by Susan Taney:

Please Be Careful!!! As I said before, make a list of the medication(s), supplement(s) and herb(s) you are taking and keep it with you. Communicate with the hospital staff for yourself or your loved one about what will be necessary for you to continue taking yourself while an inpatient and what is being administered by the hospital staff. ASK QUESTIONS. It could save you harm and potentially your life.