Clinical Briefs

By Louis Kuritzky, MD

Antihypertensive Treatment and Measurement at Home or in the Physician’s Office

A not-insubstantial minority of persons carrying a diagnosis of hypertension (HTN) actually have stress-induced transient episodes of HTN in clinicians’ offices, which we call "white coat hypertension" (w-HTN). Because w-HTN does not appear to translate into increased risk for cardiovascular events, it is generally agreed that when persons are suspected of w-HTN, ambulatory monitoring of blood pressure (the gold standard) should be performed. Persons with normal ambulatory blood pressure (ABP), despite office BP elevations, do not require treatment, unless there is evidence of target organ damage.

Because ambulatory blood pressure monitoring (ABPM) is moderately expensive (approximately $100 in our community of Gainesville, Fla) and requires specialized equipment, it would be desirable if some simpler method of BP acquisition, such as home monitoring of blood pressure (HBPM) would suffice.

This blinded, randomized, controlled trial followed patients (n = 400) from 56 primary care practices, who were followed by traditional office monitoring, ABPM, or HBPM.

Patients who used HBPM ended up with less intensive medication regimens, but this was at the expense of less overall long-term BP control. On the other hand, HBPM (compared with office measurement) resulted in almost twice as many persons discontinuing BP medication entirely due to restoration of normotension; ie, consistent HBPM ultimately determined that they were normotensive off medication. HBPM is complementary to office measurement, and may help discover w-HTN. Because there is no large data-set upon which to base the normal range of home BP, the authors suggest outcome studies to establish such BP boundaries.

Staeesen JA, et al. JAMA. 2004;291:955-964.

Inactivated Intranasal Influenza Vaccine and the Risk of Bell’s Palsy

Late in 2000, the Swiss Drug Monitoring Center and others noted numerous reports of Bell’s palsy in persons who had received NFLU. To better study the relationship between NFLU and Bell’s palsy, a case-control study of 773 persons with Bell’s palsy, compared with 2319 age-matched controls was performed.

More than 27% of patients with Bell’s palsy had received NFLU, compared with 1.1% of controls, resulting in an odds ratio of 84.0. Even at the lowest end of the confidence interval, 13 excess cases of Bell’s palsy would be seen for each 10,000 NFLU vaccinees within 3 months after vaccination.

From 2000-2001, Switzerland used an inactivated virosomal-subunit influenza vaccine (NasalfluTM), but this is no longer in clinical use. The USA has approved a different vaccine, utilizing a cold-adapted live attenuated vaccine.

Mutsch M, et al. N Eng J Med. 2004;350:896-903.

Topiramate for Migraine Prevention

Some patients remain dissatisfied with or intolerant of available migraine treatments. Early studies have found that topiramate (TOP), an anti-epileptic agent, is efficacious for migraine prevention. Although there are numerous potential pathways that might explain the efficacy of TOP, such as inhibition of voltage-gated sodium channels, most recently it has been suggested that modulation of trigeminovascular signaling may be the primary mechanism of action in migraine.

Patients suffering migraine with or without aura (n = 483) were randomized to TOP 50 mg/d, 100 mg/d, or 200 mg/d or placebo and followed for 18 weeks. The primary end point was change in migraine headache frequency per month.

At baseline, patients suffered 5-6 headaches per month, which was statistically significantly reduced by 2-3 headaches per month. with 100 mg/d and 200 mg/d TOP (but not by the 50 mg/d dose) Similarly, the number of days per month with headache was cut by 2.5-3 days/month at doses of 100 mg/d or 200 mg/d.

The most common adverse events associated with topiramate were paresthesia (50%), fatigue (14%) and anorexia (13%), but these uncommonly led to drug discontinuation. There were no serious adverse events, and modest changes in serum bicarbonate and chloride as seen in previous populations were also seen here. These data are encouraging for the clinical applicability of topiramate in patients who are not suitable candidates for other migraine treatments.

Brandes JL, et al. JAMA. 2004;291(8):965-973.

Dr. Kuritizky, Clinical Assistant Professor, University of Florida, Gainesville, is Associate Editor of Internal Medicine Alert.