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Pharmacology in the News
Geriatric Times March/April 2002 Vol. III Issue 2
Serotonergic Medications May Cause an Increase in Joint Pain
The selective serotonin reuptake inhibitors (SSRIs) and other serotonergic medications are commonly prescribed medications, particularly because of their favorable side-effect profiles. However, a report in the Journal of Clinical Psychopharmacology (2001;21[4]:458-461) found an increase of arthritic complaints in patients taking serotonergic medications.
Hood et al. reported on eight outpatients seen in their clinic over a nine-month period. Four were treated with SSRIs (fluoxetine [Prozac], sertraline [Zoloft] and paroxetine [Paxil]), three with nefazodone (Serzone) and one with venlafaxine (Effexor). The patients had new arthritic complaints or exacerbations of previous complaints within one week to one month after beginning the serotonergic medications. In this case series, knee pain was the most frequent complaint.
The arthritis persisted in one patient who switched from sertraline to venlafaxine. The other patients returned to premorbid levels within one to 12 weeks. Three of the patients who recovered changed to a different antidepressant, two discontinued their antidepressant, and two continued with the original antidepressant.
The authors noted that in animal studies, serotonin (5-HT) excess may worsen arthritic complaints and its reduction may improve them. They found that the Committee on Safety of Medicines/ Medicines Control Agency of the United Kingdom has received 970 reports of adverse reactions from SSRIs in the musculoskeletal, connective tissue and bone-disorders system, which is 2.3% of all adverse reactions reported for SSRIs.
In this series, Hood et al. found a preponderance of nefazodone-related knee arthralgia, leading them to speculate on the possibility of 5-HT2A mediation. The authors called for more research into the relationship between serotonergic medications and joint pain. For health care professionals starting their patients on these medications, they noted, "Inquiries about new or worsening joint pain should be routinely considered in the assessment of response" -- EAD
Hip Fracture Risk Increased in Patients Taking Zolpidem
In a study published in Journal of the American Geriatric Society, Philip S. Wang, M.D., Dr.P.H., and colleagues from Brigham and Women's Hospital in Boston noted that medications used to promote sleep in older patients carry the risk of numerous adverse events, including falls and hip fractures. They further noted that, based on reports of its favorable safety profile, zolpidem (Ambien) has become the most widely prescribed hypnotic. Later studies suggested that there was a comparable, if not increased, risk of side effects with zolpidem as compared to benzodiazepines.
In the Wang et al. study, the records of patients who had undergone surgical repair of a hip fracture (n=1,222) and controls matched to age and gender (n=4,888) were examined. The study population comprised individuals 65 years or older (mean=82) who had been enrolled in the New Jersey Medicare program between 1993 and 1995.
The first aim of the study was to examine the risk of hip fracture associated with zolpidem use in usual practice in a large population of older adults. Investigators also examined whether preferential use of zolpidem in patients at higher risk of hip fracture might account for an increased risk observed in zolpidem users. Finally, they compared the risk associated with zolpidem to that of other agents used to promote sleep in older people.
Wang et al. observed a 90% increased risk of hip fracture in older users of zolpidem, at least as great as the risks observed for other psychotropic medications. They cautioned that despite claims of a more favorable safety profile, zolpidem may present underrecognized risks such as impaired cognition and balance that might result in falls. Until more is learned, the investigators concluded, zolpidem should be used with caution in older people, especially those vulnerable to hip fracture -- MB
Medication Errors Found Among Home Health Care Patients
Much of the discussion of medication errors has focused on hospital inpatients. To determine the frequency of medication errors among older home health care patients, researchers conducted a cross-sectional survey of 6,718 patients between 1996 and 1998 in two large urban home health care agencies (J Am Geriatr Soc 2001;49[6]:719-724).
Two sets of expert criteria were used to define medication errors: the Home Health Criteria, which identify patients who show a pattern of symptoms indicating a possible medication-related problem; and the Beers Criteria, which include medications that experts have determined are inappropriate for older patients.
Subjects (mean age=80 years) were receiving a median of five drugs at the time of the study, and 19% were taking at least nine. Using Home Health Criteria, researchers identified possible medication errors in 19% of patients; Beers Criteria showed 17% of patients with possible errors. When both criteria were used, nearly one-third of patients had a possible error. Cardiovascular and psychotropic drugs (primarily benzodiazepines) were most commonly involved in the errors.
The potential for a medication-related error increased as the number of concurrent medications increased. When patients who were taking one to three medications were compared to those taking nine or more, percentages of possible errors were, respectively, 10% and 32% (Home Health Criteria), 8% and 32% (Beers Criteria), and 16% and 50% (both criteria).
Among drugs prescribed that should not be used in seniors, propoxyphene (used by 3.9% of subjects), long-acting benzodiazepines (2.4%) and tricyclic antidepressants (2.3%) were the most common offenders -- JH
Third Pharmaceutical Company To Offer Discount Plan
On Jan. 15, Pfizer Inc. announced the launch of a prescription discount card plan for seniors. Set to begin March 1, the Share Card will offer seniors a flat fee of $15 per prescription rather than the discount formula used in the discount plans of Novartis and GlaxoSmithKline (GSK), which began Jan. 1.
The plan will be administered by a pharmacy benefit management company and includes two medications that are co-marketed with UCB Pharma (cetirizine [Zyrtec]) and Eisai (donepezil [Aricept]). Celecoxib (Celebrex) and valdecoxib (Bextra), which are co-marketed with Pharmacia, will not be included.
According to a press release from Pfizer, nine of its 80 products are among the 50 most prescribed medications for seniors.
Although the flat fee may generate deeper discounts per prescription than the 25% discount offered by Novartis and GSK, fewer seniors will be eligible for the Share Card plan. The other two plans include seniors with incomes up to 300% of the poverty level ($8,590 during 2001), but the Pfizer plan caps income at 200% of the poverty level.
Bristol-Myers Squibb and AstraZeneca are both reported to be preparing prescription discount plans for seniors -- EAD
