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Hepatitis agent cloned and designated hepatitis G virus
SCIENCE AND MEDICINE
NEWS FDA committee rules calcium-channel blockers safe advisory committee the US Food & Drug Administration decided that, despite the findings of two recently published studies, most calcium-channel blockers (CCBs) are safe for use in patients with hypertension. The n Jan 25,
to
controversy
an
over
whether this class of
actually contribute to increased incidence of myocardial infarction (MI) or other adverse cardiac events in people taking them for hypertension has raged ever since Dr Bruce Psaty announced results of a case-controlled study last March. Several panelists did urge a recall of short-acting nifedipine (Adalat, [Bayer] and Procardia [Pfizer]), as drugs
may
has Public Citizen’s Health Research Group. Instead the panel recommended strengthening the labelling to indicate it should not be used in Dr Bob Temple, direcof FDA’s Office of Drug Evaluation I, said that the agency had already decided to do so, even though the drug is not approved for hypertension. Yet many doctors still prescribe this form of nifedipine for hypertension. Labelling will also be changed to indicate that short-acting nifedipine is not indicated for unstable angina. But for other CCBs, Temple said, "I don’t think we’ve heard anything that should make people nervous".
hypertension. tor
Psaty’s study (7AAIA 1995; 274: 620-25) claimed that some shortacting CCBs increased the risk of MI. Psaty and Dr Curt Furberg reported similar results in a metaanalysis published a few weeks later (Cz’rculatioiz 1995; 92: 1326-30). Presenting data from both studies, of which indicated a 60% one increase in heart attacks for those on CCBs, Psaty attacked a study by Dr Hershel Jick, of Boston University, which Jick later presented. Jick’s unpublished case-controlled analysis showed that CCBs decreased the risk of MI. A meta-analysis of verapamil trials by Dr Robert Makuch, a Yale epidemiologist, showed that the drug reduced mortality and incidence of coronary events.
Furberg caused a stir by also attacking Jick (who in turn called into question Furbergs "scientific credibility" for making "glib" comments about his data), and then condemning all CCBs, saying that without long-term safety data, the FDA and drug manufacturers might as well be handing out poison. The only CCB with a good record is verapamil, he claimed. Furberg also shocked the audience by citing a potential linkage of CCBs to autoimmune disease, saying that CCBs seemed to block apoptosis. The committee, however, agreed
with Harvard epidemiologist Dr Charles Hennekens, that casecontrolled studies and meta-analyses do not provide enough solid evidence to judge CCBs. Both called for randomised, controlled trials to compare CCBs with each other and with angiotensin-converting-enzyme (ACE) inhibitors, diuretics, and (3blockers. Such a trial-ALLHAT-is under way at the National Institutes of Health. Unlike ACE inhibitors and pblockers, CCBs have not ever been shown to be cardioprotective, which is partly why they have been suspect. According to Hemant K Shah, an independent stock analyst (Warren, New Jersey), sales of CCBs have begun to decline. Pfizer said that in the last quarter, even sales of its extended release nifedipine
(Procardia XL) dropped-by 9%because of concerns. p-blockers and diuretics have also become more popular since the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure recommended in 1993 that they be used as first-line therapies
Many managed-care organisations and other large purchasers have followed that advice.
Alicia Ault Barnett
Hepatitis agent cloned and designated hepatitis G virus international team of has cloned a new hepatitis agent and designated it hepatitis G virus (HGV). It is an RNA virus of the family Flaviviridae. HGV seems to be closely related to another recently identified hepatitis virus, GBV-C, and distantly to hepatitis C (HCV), both also flaviviruses. The researchers report (Linnen et al, Science 1996; 271: 505-06) that of 13 cases of post-transfusion hepatitis in which hepatitis A to E had been ruled out, three cases
)B n
nxesearchers
HGV RNA positive. All three had been HGV RNA-negative before the transfusions. In two of the three, donor serum was available and was HGV RNA-positive. The virus seems to have a role in community-acquired disease as well. Of 38 cases of acute hepatitis reported to a sentinel study by the US Centers for Disease Control and Prevention not ascribable to hepatitis A to E, five (13%) were HGV-RNA positive. In addition, of 107 patients with acute hepatitis C identified during the same period,
were
(18%) were also HGV RNApositive. In a study to assess the 19
risk of transfusion transmission in the US, the researchers found that of 779 consecutively screened volunteer blood donors who had normal alanine aminotransferase levels (<45 IU/mL), 13 (1-3%) were HGV RNA-positive. "None of the donors implicated in transfusionmediated HGV transmission had an elevated ALT level at the time of donation", the researchers noted. Michael
McCarthy
313
NEWS FDA committee rules calcium-channel blockers safe advisory committee the US Food & Drug Administration decided that, despite the findings of two recently published studies, most calcium-channel blockers (CCBs) are safe for use in patients with hypertension. The n Jan 25,
to
controversy
an
over
whether this class of
actually contribute to increased incidence of myocardial infarction (MI) or other adverse cardiac events in people taking them for hypertension has raged ever since Dr Bruce Psaty announced results of a case-controlled study last March. Several panelists did urge a recall of short-acting nifedipine (Adalat, [Bayer] and Procardia [Pfizer]), as drugs
may
has Public Citizen’s Health Research Group. Instead the panel recommended strengthening the labelling to indicate it should not be used in Dr Bob Temple, direcof FDA’s Office of Drug Evaluation I, said that the agency had already decided to do so, even though the drug is not approved for hypertension. Yet many doctors still prescribe this form of nifedipine for hypertension. Labelling will also be changed to indicate that short-acting nifedipine is not indicated for unstable angina. But for other CCBs, Temple said, "I don’t think we’ve heard anything that should make people nervous".
hypertension. tor
Psaty’s study (7AAIA 1995; 274: 620-25) claimed that some shortacting CCBs increased the risk of MI. Psaty and Dr Curt Furberg reported similar results in a metaanalysis published a few weeks later (Cz’rculatioiz 1995; 92: 1326-30). Presenting data from both studies, of which indicated a 60% one increase in heart attacks for those on CCBs, Psaty attacked a study by Dr Hershel Jick, of Boston University, which Jick later presented. Jick’s unpublished case-controlled analysis showed that CCBs decreased the risk of MI. A meta-analysis of verapamil trials by Dr Robert Makuch, a Yale epidemiologist, showed that the drug reduced mortality and incidence of coronary events.
Furberg caused a stir by also attacking Jick (who in turn called into question Furbergs "scientific credibility" for making "glib" comments about his data), and then condemning all CCBs, saying that without long-term safety data, the FDA and drug manufacturers might as well be handing out poison. The only CCB with a good record is verapamil, he claimed. Furberg also shocked the audience by citing a potential linkage of CCBs to autoimmune disease, saying that CCBs seemed to block apoptosis. The committee, however, agreed
with Harvard epidemiologist Dr Charles Hennekens, that casecontrolled studies and meta-analyses do not provide enough solid evidence to judge CCBs. Both called for randomised, controlled trials to compare CCBs with each other and with angiotensin-converting-enzyme (ACE) inhibitors, diuretics, and (3blockers. Such a trial-ALLHAT-is under way at the National Institutes of Health. Unlike ACE inhibitors and pblockers, CCBs have not ever been shown to be cardioprotective, which is partly why they have been suspect. According to Hemant K Shah, an independent stock analyst (Warren, New Jersey), sales of CCBs have begun to decline. Pfizer said that in the last quarter, even sales of its extended release nifedipine
(Procardia XL) dropped-by 9%because of concerns. p-blockers and diuretics have also become more popular since the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure recommended in 1993 that they be used as first-line therapies
Many managed-care organisations and other large purchasers have followed that advice.
Alicia Ault Barnett
Hepatitis agent cloned and designated hepatitis G virus international team of has cloned a new hepatitis agent and designated it hepatitis G virus (HGV). It is an RNA virus of the family Flaviviridae. HGV seems to be closely related to another recently identified hepatitis virus, GBV-C, and distantly to hepatitis C (HCV), both also flaviviruses. The researchers report (Linnen et al, Science 1996; 271: 505-06) that of 13 cases of post-transfusion hepatitis in which hepatitis A to E had been ruled out, three cases
)B n
nxesearchers
HGV RNA positive. All three had been HGV RNA-negative before the transfusions. In two of the three, donor serum was available and was HGV RNA-positive. The virus seems to have a role in community-acquired disease as well. Of 38 cases of acute hepatitis reported to a sentinel study by the US Centers for Disease Control and Prevention not ascribable to hepatitis A to E, five (13%) were HGV-RNA positive. In addition, of 107 patients with acute hepatitis C identified during the same period,
were
(18%) were also HGV RNApositive. In a study to assess the 19
risk of transfusion transmission in the US, the researchers found that of 779 consecutively screened volunteer blood donors who had normal alanine aminotransferase levels (<45 IU/mL), 13 (1-3%) were HGV RNA-positive. "None of the donors implicated in transfusionmediated HGV transmission had an elevated ALT level at the time of donation", the researchers noted. Michael
McCarthy
313