GAO-01-286R Drugs Withdrawn From Market

United States General Accounting Office

Washington, DC 20548

January 19, 2001

The Honorable Tom Harkin

The Honorable Olympia J. Snowe

The Honorable Barbara A. Mikulski

United States Senate

The Honorable Henry A. Waxman

House of Representatives

Subject: Drug Safety: Most Drugs Withdrawn in Recent Years Had Greater Health

Risks for Women

The Food and Drug Administration (FDA) approves drugs for sale in the United

States based on its determination that the clinical benefits of a drug outweigh its

potential health risks. To make this decision, FDA reviews supporting data collected

from several thousand patients during the drug’s development. Once a drug is

approved for marketing and used by potentially hundreds of thousands of patients,

however, the type, rate, and severity of adverse events caused by the drug can be

much different than those detected during the drug’s development. In some cases,

FDA or drug manufacturers have acted to remove from the market drugs that have

been shown to have unacceptable health risks once they were in widespread use.

You requested that we identify drug products withdrawn from the market in the

United States since January 1, 1997, and that we note which of the withdrawn drugs

posed greater health risks for women than for men. We collected this information

from publicly available sources, primarily FDA documents and research articles from

the medical literature. We also consulted drug safety experts. We looked only at

prescription pharmaceuticals, not at vaccines or over-the-counter medicines.1

 We

conducted our work from December 2000 to January 2001 in accordance with

generally accepted government auditing standards.

 1

Although not included in our sample of withdrawn drugs, ingredients are occasionally removed from

nonprescription drugs because they are proven to pose serious health risks. For example, on Nov. 6,

2000, FDA took steps to remove phenylpropanolamine (PPA) from all drug products and requested

that all drug companies discontinue marketing products containing PPA. PPA, which could be found

in many over-the-counter (OTC) and prescription cough and cold medications and OTC weight loss

products, was reported to increase the risk of hemorrhagic stroke (bleeding into the brain or tissue

around the brain) in women but not in men. See W.N. Kernan and others, “Phenylpropanolamine and

the Risk of Hemorrhagic Stroke,” New England Journal of Medicine, Vol. 343, No. 25 (2000), pp. 1826-

32.
2 GAO-01-286R Drugs Withdrawn From Market

In summary, we found that 10 prescription drugs have been withdrawn from the U.S.

market since January 1, 1997. Eight of the 10 prescription drugs posed greater health

risks for women than for men: four of these may have led to more adverse events in

women because they were prescribed more often to women than to men, while the

other four had more adverse events in women even though they were widely

prescribed to both women and men. Of the two remaining withdrawn drugs, one

belongs to a class of drugs known to pose a greater health risk for women, but we

were unable to find direct evidence that the adverse events that contributed to its

withdrawal occurred predominantly in women. We found no direct evidence that the

health risks for the remaining withdrawn drug differed for women and men. In

comments on a draft of this letter, FDA generally agreed with our analysis.

Eight of the 10 prescription drugs withdrawn since January 1, 1997, posed greater

health risks for women than for men (see table 1). For four of the withdrawn drugs,

the greater health risk may have been due to a higher level of use among women. For

example, the appetite suppressants Pondimin and Redux were withdrawn from the

U.S. market because they caused valvular heart disease in some patients. Although

the majority of the reported cases were in women, most of the users were women, so

the apparent gender-related effects could be a reflection of the products’ usage

patterns.2

 Similarly, women accounted for more than two-thirds of the deaths due to

liver failure in patients taking Rezulin, but women also were prescribed Rezulin more

often than men.3

Finally, it is likely that Lotronex posed a greater health risk for

women because the drug was approved to treat irritable bowel syndrome in women

only.4

Four other withdrawn drugs posed greater health risks for women even though they

were widely prescribed to both women and men. Posicor, which was approved for

the treatment of hypertension and angina, slowed or stopped the heart rate in

otherwise healthy people, especially elderly women, and interacted with 26 different

drugs.5 Greater health risks for women may be due to physiological differences that

 2

See FDA, Center for Drug Evaluation and Research (CDER), Questions and Answers About the

Withdrawal of Fenfluramine (Pondimin) and Dexfenfluramine (Redux),

http://www.fda.gov/cder/news/phen/fenphenqa2.htm (downloaded Dec. 20, 2000); H.M. Connolly and

others, “Valvular Heart Disease Associated with Fenfluramine-Phentermine,”New England Journal of

Medicine, Vol. 337, No. 9 (1997), pp. 581-88; D.J. Graham, and L. Green, “Further Cases of Valvular

Heart Disease Associated with Fenfluramine-Phentermine,”New England Journal of Medicine, Vol. 337,

No. 9 (1997), p. 635.

3

See J. Kohlroser and others, “Hepatotoxicity Due to Troglitazone: Report of Two Cases and Review of

Adverse Events Reported to the United States Food and Drug Administration,” American Journal of

Gastroenterology, Vol. 95, No. 1 (2000), pp. 272-76; FDA, CDER, presentation of D. Graham,

Endocrinologic and Metabolic Drugs Advisory Committee Meeting No. 72 (Mar. 26, 1999), pp. 94-95.

4

See FDA talk paper, Glaxo Wellcome Decides to Withdraw Lotronex From the Market (Nov. 28, 2000),

http://www.fda.gov/bbs/topics/answers/anhs01058.html (downloaded Dec. 20, 2000); FDA, CDER,

Lotronex Questions and Answers, http://www.fda.gov/cder/drug/infopage/lotronex/lotronex-qa.htm

(downloaded Dec. 20, 2000).

5

See Medwatch: The FDA Medical Products Reporting Program, Background: Posicor Labeling

Changes (Dec. 18, 1997), http://pharminfo.com/medwatch/mwrpt31.html (downloaded Nov. 29, 2000).
3 GAO-01-286R Drugs Withdrawn From Market

Table 1: Prescription Drugs Withdrawn From the United States Market, Jan. 1, 1997 Through Dec.

31, 2000

Drug Type of Drug Date

Approved

Date

Withdrawn Primary Health Risk

Prescription Drugs With Evidence of Greater Health Risks in Women

Pondimin

(fenfluramine

hydrochloride)

Appetite

suppressant 6/14/1973 9/15/1997 Valvular heart disease

Redux

(dexfenfluramine

hydrochloride)

Appetite

suppressant 4/29/1996 9/15/1997 Valvular heart disease

Seldanea

(terfenadine) Antihistamine 5/8/1985 2/27/1998 Torsades de Pointes (potentiallyfatal irregular heartbeat)

Posicor

(mibefradil

dihydrochloride)

Cardiovascular 6/20/1997 6/8/1998

Lowered heart rate in elderly

women and adverse interactions

with 26 other drugs

Hismanal

(astemizole) Antihistamine 12/19/1988 6/18/1999 Torsades de Pointes

Rezulin

(troglitazone) Diabetic 1/29/1997 3/21/2000 Liver failure

Propulsidb

(cisapride

monohydrate)

Gastrointestinal 7/29/1993 7/14/2000 Torsades de Pointes

Lotronex

(alosetron

hydrochloride)

Gastrointestinal 2/9/2000 11/28/2000

Ischemic colitis (intestinal

inflammation due to lack of

blood flow)

Prescription Drugs Without Evidence of Greater Health Risks in Women

Raxar

(grepafloxacin

hydrochloride)

Antibiotic 11/6/1997 11/1/1999 Torsades de Pointes

Duract

(bromfenac

sodium)

Analgesic and

anesthetic 7/15/1997 6/22/1998 Liver failure

a

Seldane-D was also withdrawn from the market Feb. 27, 1998. Terfenadine was the active ingredient in both

Seldane and Seldane-D; Seldane-D also contained the decongestant pseudoephedrine.

b

Propulsid remains minimally available on a patient-by-patient basis for those with severely debilitating conditions.

Source: GAO analysis.
4 GAO-01-286R Drugs Withdrawn From Market

make women differentially more susceptible to some drug-related health risks.

Seldane, Hismanal, and Propulsid can in some circumstances prolong the interval

between the heart muscle’s contractions and induce Torsades de Pointes (TdP), a

potentially fatal cardiac arrhythmia. Women have a higher incremental risk of

suffering an arrhythmia after taking these drugs than do men probably because (1)

the interval between heart muscle contractions is naturally longer for women than for

men and (2) male sex hormones moderate the heart muscle’s sensitivity to these

drugs.6

The remaining two withdrawn drugs have not demonstrated a greater health risk for

women. The first, Raxar, belongs to a class of drugs (fluoroquinolone antibiotics)

known to pose a greater health risk for women. Since the early 1990s, there has been

mounting evidence that fluoroquinolone antibiotics, antiarrhythmic drugs,

antihistamines (for example, Seldane and Hismanal), and gastrointestinal prokinetics

(for example, Propulsid) prolong heart muscle contractions and induce TdP.7

However, there is no conclusive evidence that the adverse events that contributed to

Raxar’s withdrawal occurred primarily in women. For the second, Duract, we found

no evidence that the risk of adverse events differed for women and men.

It is important to note that an examination of drug withdrawals, by itself, does not

provide a complete picture of drug safety. First, drug withdrawals do not reflect a

judgment concerning the absolute safety of a drug but reflect a judgment about the

risks and rewards of a drug in the context of alternative treatments. For instance,

despite the documented deaths from liver failure among patients taking Rezulin, the

drug was not withdrawn from the market until FDA approved new, safer medications

with similar benefits. On the other hand, Raxar was withdrawn from the market on

the basis of relatively few adverse event reports because alternative treatments were

readily available.

Second, drug withdrawals may occur because the drugs are used incorrectly by

health professionals and patients, not because the drugs are inherently dangerous

 6

See Georgetown Center for Education and Research on Therapeutics, Drugs That Prolong the QT

Interval and/or Induce Torsades de Pointes (Sept. 1, 2000), http://www.torsades.org (downloaded Dec.

20, 2000); R.L. Woosley, “From Bench to Bedside: Role of Gender-Based Therapeutics in the Clinical

Care of Women,” Journal of Women’s Health, Vol. 7, No. 1 (1998), pp. 21-23; S.N. Ebert and others,

“Female Gender as a Risk Factor for Drug-Induced Cardiac Arrhythmias: Evaluation of Clinical and

Experimental Evidence,” Journal of Women’s Health, Vol. 7, No. 5 (1998), pp. 547-57; C. Hart,

“Monitoring Medications in the Marketplace,” Modern Drug Discovery, Vol. 3, No. 5 (2000), pp. 40-41,

43-44, http://pubs.acs.org/hotartcl/mdd/oo/jun/mddhart.html (downloaded Dec. 18, 2000); W.

Haverkamp, “The Potential for QT Prolongation and Proarrhythmia by Non-Antiarrhythmic Drugs:

Clinical and Regulatory Implications,” Report on a Policy Conference of the European Society of

Cardiology 2000, European Heart Journal, http://www.idealibrary.com (downloaded Dec. 12, 2000);

J.T. Barbey and others, “Spontaneous Adverse Event Reports of Serious Ventricular Arrhythmias, QT

Prolongation, Syncope, and Sudden Death in Patients Treated with Cisapride” (obtained from J.T.

Barbey Jan. 5, 2000, submitted for publication).

7

See Woosley, pp. 21-23; Ebert and others, pp. 547-57; Hart, pp. 40-41, 43-44; L. Patmore and others,

“Effects of Sparfloxacin, Grepafloxacin, Moxifloxacin, and Ciprofloxacin on Cardiac Action Potential

Duration,” European Journal of Pharmacology, Vol. 406, No. 3 (2000), pp. 449-52.
5 GAO-01-286R Drugs Withdrawn From Market

when used correctly. For example, Duract was approved by FDA only for short-term

use (less than 10 days) for acute pain, but some physicians continued to prescribe it

for longer periods despite efforts by FDA and the manufacturer to educate physicians

about the dangers of doing so. Similarly, the health risks associated with Seldane

occurred when the drug was taken in combination with medications that were

contraindicated on Seldane’s label.

Third, the off-label use of drugs also can be problematic because such use may not

have been shown to be safe and effective. For example, while Pondimin

(fenfluramine) was approved for short-term use as an appetite suppressant, it was

increasingly prescribed and used in combination with the appetite suppressant

phentermine as a part of a long-term weight loss and management program. The offlabel use of this combination known as “fen-phen” posed serious health risks for

women.8

AGENCY COMMENTS

We received written comments from FDA on a draft of this letter (see enclosure).

FDA generally agreed with our description of the issues and provided technical

comments, which we have incorporated where appropriate. FDA also suggested that

we distinguish more clearly between withdrawn drugs that led to more adverse

events in women because they were prescribed more often to women and those that

caused more adverse events in women even though the drugs were roughly

prescribed on an equal basis to women and men. We have revised the letter to clarify

this distinction. FDA also suggested that we include Raxar in the list of drugs with

greater health risks for women because it belongs to a class of drugs with known

risks for women. We did not do so because, as FDA’s comments acknowledge, it has

not been shown that the adverse events that led to Raxar’s withdrawal occurred

primarily in women.

- - - - -

 8

The use of phentermine alone has not been associated with valvular heart disease.
6 GAO-01-286R Drugs Withdrawn From Market

We plan no further distribution of this correspondence until 30 days after the date of

this letter. At that time, we will send copies of this letter to the Commissioner of FDA

and to others who request it. The letter will also be available on GAO's home page at

http://www.gao.gov.

Major contributors to this letter were Martin T. Gahart, Emily J. Rowe, and Lisanne

Bradley. Please contact me at (202) 512-7119 if you have any questions.

Janet Heinrich, Director

Health Care—Public Health Issues

Enclosure
ENCLOSURE ENCLOSURE

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ENCLOSURE ENCLOSURE

8 GAO-01-286R Drugs Withdrawn From Market

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