Letters to the Editor - May 1, 2000 - American Academy of Family Physicians

Letters to the Editor

Oral Contraceptives and Prevention of Implantation

TO THE EDITOR: The article "Update on Oral Contraceptive Pills"¹ was timely and informative. However, one critical piece of information was overlooked.

When prescribing oral contraceptive pills (OCPs), particularly when they are to be used as "emergency contraception," it is important for physicians to remember that one of the potential mechanisms of action is prevention of implantation.² Given that the United States has a diverse population, it is probable that a substantial number of women seeking birth control or "emergency contraception" subscribe to the belief that the fetus is a human being from the time of conception, and that it is morally wrong to interfere with the life of that human being for any reason, with the possible exception of a significant danger to the life of the mother. Therefore, it is incumbent on physicians who prescribe OCPs to review the possible mechanisms of action with all patients, so that those who would choose not to take the chance of allowing conception but preventing implantation, can make a truly informed decision. This is particularly important when prescribing OCPs for "emergency contraception," where the probability of failing to prevent ovulation and successfully preventing implantation is much higher than with the usual use.

It should be noted that "emergency contraception" is an unsatisfactory term because it may give the impression to the lay person that conception is reliably being prevented. Conception may be prevented when OCPs or Preven (levonorgestrel and ethinyl estradiol) are used, but, as noted earlier, prevention of implantation is also a possible mechanism of action. Depending on the timing of administration of the medication, it may even be a more likely mechanism. Prevention of implantation is nearly certain when an intrauterine device is used, making "emergency contraception" an even more inappropriate term.

JEREMY KLEIN, M.D.
412 North Lock Ave.
Louisa, KY 41230

REFERENCES

Cerel-Suhl SL, Yeager BF. Update on oral contraceptive pills. Am Fam Physician 1999;60:2073-84.

Physician's Desk Reference. 53rd ed. Montvale, N.J.: Medical Economics, 1999:2222.

TO THE EDITOR: The article "Update on Oral Contraceptive Pills"¹ provides a fairly thorough overview of many of the issues surrounding the prescribing of this form of fertility control. It did not, however, include certain information on oral contraceptive pills (OCPs) that is essential for at least some patients, to make an informed choice on the use of OCPs that is consistent with their values. That information concerns the mechanisms of action of these agents.

While the predominant mode of action of combination hormonal contraceptives is that of ovulation suppression, this effect is not total, with some degree of breakthrough ovulation occurring in up to 10 percent of cycles.^2,3 Other mechanisms of action (changes in the cervical mucus and endometrium) are recognized⁴ and mentioned in the prescribing information.⁵ The endometrial changes make implantation less likely,⁴ which is a mechanism that occurs after fertilization. It is unknown how often a postfertilization effect occurs, but some estimate can be made by examining the ratio of ectopic to intrauterine pregnancies. This ratio is elevated in women who take OCPs versus those who do not.⁶Even if the likelihood of this occurring in any one cycle is low, the likelihood that a patient will eventually encounter this mechanism over years of OCP use would be high.

For a patient who is of the conviction that human life begins at fertilization, these effects are serious concerns. I am aware of patients with such convictions who were placed on OCPs without any mention of this by the prescriber, and who were later quite upset when informed of the potential for a postfertilization mode of action.

I believe it is imperative for all physicians who prescribe OCPs to provide information about the potential for a postfertilization effect. Patients can then make a more fully informed choice about fertility control options. Certainly, family physicians, who aim to treat the whole person, should seek to be aware of situations in which prescribed drugs may not be consonant with the value systems of our patients.

ALAN L. MCGAUGHRAN, M.D.
Blairsville Family Health Center
56 Club Lane
Blairsville, PA 15717

REFERENCES

Cerel-Suhl SL, Yeager BF. Update on oral contraceptive pills. Am Fam Physician 1999;60:2073-84.

Goldzieher JW, Pena A, Chenault CB, Woutersz TB. Comparative studies of the ethynyl estrogens used in oral contraceptives II. Antiovulatory potency. Am J Obstet Gynecol 1975;122:619-24.

Rice-Wray E, et al. Clinical evaluation of norethindrone acetate in fertility control. Am J Obstet Gynecol 1965;93:115-21.

Baird DT, Glasier AF. Hormonal contraception. N Engl J Med 1993;328:1543-9.

Physician's Desk Reference. 53rd ed. Montvale, N.J.: Medical Economics, 1999:713,846,2204, 2283,2937,3221,3257,3326.

Jop-Spira N. Risk of chlamydial PID and oral contraceptives. [Letter] JAMA 1990;264:2072-4.

EDITOR'S NOTE: These letters were sent to the authors of "Update on Oral Contraceptive Pills," who declined to reply.

An Uninvited Guest in the Ear

TO THE EDITOR: Spring is the best season in Tokyo, with cherry trees blossoming beautifully after the winter rest. However, many uninvited guests are also awakening from their sleep.

FIGURE. A bug stuck in the external auditory canal. The bug seemed to be struggling to reach the patient's eardrum.

This spring, a 40-year-old man was admitted to our clinic with a sudden onset of tinnitus and severe pain in the left ear. The tinnitus and pain occurred simultaneously while the patient was sleeping. On examination, we found a bug stuck in the external auditory canal (see the accompanying figure). The bug seemed to be struggling to reach the patient's eardrum. We applied a topical anesthetic (4 percent lidocaine), which had a desirable effect on the patient and the bug.^1-4 It was immobilized and easily removed with forceps.

The bug was a cockroach. We had seen some reports like this one.^1-5 For anatomic reasons, a cockroach is generally unable to back out of the external auditory canal. The more it tries to back out, the more stuck it becomes. In this case, the use of a topical anesthetic decreased the patient's symptoms and also removed the bug's confusion.

After removal of the bug, the patient's symptoms disappeared completely. We informed him that a "pretty insect" had been stuck in his ear. To prevent adverse psychologic reaction, we did not tell him it was a cockroach. The patient is now able to sleep comfortably. What about the cockroach? It is also sleeping, in formalin.

KOICHI TSUNODA, M.D.
Department of Otolaryngology
Nissan Tamagawa Hospital
Tokyo, Japan

TOM BAER, PH.D.
Department of Experimental Psychology
University of Cambridge
Cambridge, U.K.

REFERENCES

Schittek A. Insect in the external auditory canal--a new way out. JAMA 1980;243:331.

O'Toole K, Paris PM, Steward RD, Martinez R. Removing cockroaches from the auditory canal: controlled trial. N Engl J Med 1985;312:1197.

Cantrell H. More on removing cockroaches from the auditory canal. N Engl J Med 1986;314:720.

Leffler S, Cheney P, Tandberg D. Chemical immobilization and killing of intra-aural roaches: an in vitro comparative study. Ann Emerg Med 1993;22:1795-8.

Warren J, Rotello LC. Removing cockroaches from the auditory canal: a direct method. N Engl J Med 1989;320:322.

Asymptomatic Microscopic Hematuria

TO THE EDITOR: In Drs. Thaller and Wang's well-written article, "Evaluation of Asymptomatic Microscopic Hematuria in Adults,"¹ some statements regarding the use of radiographic contrast media may be misleading to family physicians. The article states that the incidence of death following this procedure has been reported to be one case per 40,000 administrations. Recent literature indicates that the incidence of fatal reaction might be much lower. A study² involving more than 337,000 patients who were given high-osmolar ionic contrast media or low-osmolar nonionic contrast media revealed no fatalities attributable to the radiographic contrast media. In a meta-analysis³ involving more than 584,000 administrations of high-osmolar ionic or low-osmolar nonionic contrast media, the fatality rate was 0.9 deaths per 100,000 administrations.

Many of the reviewed studies, including the work of Katayama and colleagues,² have been criticized for nonrandom selection. That is, patients with higher risk stratification preferentially received low-osmolar nonionic contrast media. While this is a legitimate criticism of scientific method, it is also a reflection of real world practice and, thus, the statistical yield may reflect the actual risk in a properly screened and treated population. Regardless, numerous reviewers of the data have concluded that because of the extremely low incidence of fatal reaction to radiographic contrast media, studies would have to include several million cases for an accurate determination of the frequency of fatal reaction. In support of Drs. Thaller and Wang,¹ numerous studies do uphold the concept of lower nonfatal, adverse reactions in patients who were administered low-osmolar nonionic contrast media compared with high-osmolar ionic contrast media.

In addition, the authors imply that severe reactions to radiographic contrast media are anaphylactic in nature.¹ In fact, most of the unexpected reactions to this are anaphylactoid. True antigen-antibody mediated anaphylactic reactions to radiographic contrast media are extremely rare: I was able to find only three documented human cases of antibody-mediated adverse reactions.⁴

Finally, no mention was made of the late reactions to radiographic contrast media that are likely to be seen by family physicians. At least one large study⁵ has revealed that late reactions were at least as common as immediate reactions. Fortunately, these reactions were almost invariably self-limited. However, failure to recognize a late reaction could lead to omission of pretreatment or improper risk stratification and, thus, an increased risk of adverse reaction on subsequent radiographic contrast media administration.

ROBERT B. HASH, M.D.
Mercer University School of Medicine
1550 College St.
Macon, GA 31207

REFERENCES

Thaller TR, Wang LP. Evaluation of asymptomatic microscopic hematuria in adults. Am Fam Physician 1999;60:1143-52.

Katayama H, Yamaguchi K, Kozuka T, Takashima T, Seez P, Matsuura K, et al. Adverse reactions to ionic and nonionic contrast media: a report from the Japanese Committee on the Safety of Contrast Media. Radiology 1990;175:621-8.

Caro JJ, Trindade E, McGregor M. The risks of death and severe nonfatal reactions with high- vs. low-osmolality contrast media: a meta-analysis. Am J Roentgenol 1991;156:825-32.

Almen T. The etiology of contrast medium reactions. Invest Radiol 1994;29(Suppl 1):S37-45.

Yoshikawa, H. Late adverse reactions to nonionic contrast media. Radiology 1992;183:737-40.

TO THE EDITOR: In their recent review of microscopic hematuria, Drs. Thaller and Wang did a nice job of simplifying a complex subject.¹ However, I believe that their unequivocal recommendation that all patients except children with microscopic hematuria undergo urologic evaluation is controversial. I would like to have seen the authors discuss the alternative approaches. In young adults without risk factors, the incidence of urologic malignancy is quite low. Subjecting all such patients to invasive urologic evaluation may not be in their best interest.

In their recent review of microscopic hematuria, Grossfield and Carroll² discuss the difference in urologic cancer rates between a referral population and a primary care population. Even though they recommend that most patients who are referred to a urologist undergo a thorough evaluation, they acknowledge that a number of sources have questioned the need for cystoscopy in younger patients without risk factors.

Connelly, in Diagnostic Strategies for Common Medical Problems,³ wrote an evidence-based, primary care oriented review of microscopic hematuria. She recommends follow-up observation as the preferred approach for patients who are without risk factors, are asymptomatic and are less than 50 years of age.

The editors of American Family Physician should be applauded for developing the "Problem-Oriented Diagnosis" series. I believe, however, that they should ensure that the recommended diagnostic approaches be based on evidence and when evidence is lacking and controversy exists, it be addressed.

M. LEE CHAMBLISS, M.D., M.S.P.H.
Moses Cone Family Medicine Residency
Greensboro, NC 27401

REFERENCES

Thaller TR, Wang LP, Evaluation of asymptomatic microscopic hematuria in adults. Am Fam Physician 1999;60:1143-52.

Grossfeld GD, Carroll PR. Evaluation of asymptomatic microscopic hematuria. Urol Clin North Am 1998;25:661-76.

Connelly JE. Microscopic hematuria. In: Diagnostic Strategies for Common Medical Problems. 2nd ed. Philadelphia: American College of Physicians, 1999:518-26.

EDITOR'S NOTE: These letters were sent to the authors of "Evaluation of Asymptomatic Microscopic Hematuria in Adults," who did not reply.

Corrections

Figures 4 and 6 in the article "Diagnosis and Treatment of Endometriosis" (October 15, 1999, page 1753) were incorrectly oriented. Although the labels and indicator lines are correct, the figures were flipped from front to back.

The article "Pediatric Advanced Life Support: A Review of the AHA Recommendations" (October 15, 1999, page 1743) contained an error in Table 6. When describing the types of dysrhythmias in the first column, the table should have stated "pulseless" electrical activity.

Table 5 in the article "Management of Acute Gastroenteritis in Children" (December 1999, page 2555) contained an error. The amount of potassium chloride or potassium salt in the home mix rehydration recipe developed by the World Health Organization is 1/4 teaspoon, to equal 1.5 g.

*These corrections have been made to the online version of AFP. The links above will take you to the corrected items, which remain part of the online issues in which they were originally published.

Send letters to Jay Siwek, M.D., Editor, American Family Physician, 11400 Tomahawk Creek Parkway, Leawood, KS 66211-2672; fax:913-906-6080; e-mail: afplet@aafp.org. Please include your complete address, telephone number and fax number. Letters should be double-spaced, fewer than 500 words and limited to one table or figure and six references. Please submit a word count. Letters submitted for publication in AFP must not be submitted to any other publication. Possible conflicts of interest must be disclosed at time of submission. Submission of a letter constitutes transfer of copyright to the American Academy of Family Physicians. The editors may edit letters to meet style and space requirements.

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