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Archive for the ‘Pharmacology’ Category

The Impact of ALLHAT

Posted by medliorator on March 12, 2009

Andrew Pollack:

Allhat [Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial] began enrolling patients with high blood pressure, age 55 and older, in 1994, with more than 42,000 people eventually participating.

patients receiving the Norvasc [CCB, Pfizer] had a 38 percent greater incidence of heart failure than those on the diuretic. And those receiving the ACE inhibitor… had a 15 percent higher risk of strokes and a 19 percent higher risk of heart failure.

The percentage of hypertension patients receiving a diuretic rose to around 40 percent in the year after the Allhat results were announced, up from 30 to 35 percent beforehand, according to some studies. But use of diuretics has since stayed at that plateau. And over all, use of newer hypertension drugs has grown faster than the use of diuretics since 2002

The aftereffects of the study show how hard it is to change medical practice, even after a government-sanctioned trial costing $130 million produced what appeared to be solid evidence.

A confluence of factors blunted Allhat’s impact. One was the simple difficulty of persuading doctors to change their habits. Another was scientific disagreement

Even before Allhat was finished, and certainly since then, new drugs appeared. Others, meanwhile, became available as generics, reducing the cost advantage of the diuretics. And many doctors have shifted to using two or more drugs together

So Allhat’s main query — which drug to use first — became “an outdated question that doesn’t have huge relevance to the majority of people’s clinical practices,” said Dr. John M. Flack, the chairman of medicine at Wayne State University

The Minimal Impact of a Big Hypertension Study [NYT]

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21 Fraudulent Studies Retracted

Posted by medliorator on March 11, 2009

Baystate Medical Center in Springfield, Mass., has asked several anesthesiology journals to retract the studies, which appeared between 1996 and 2008, the WSJ reports. The hospital says its former chief of acute pain, Scott S. Reuben, faked data used in the studies.

Take a look at Reuben’s work here.

A New Low in Drug Research: 21 Fabricated Studies [WSJ Health Blog]

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Fertility Drugs and Ovarian Cancer – No Associations Found

Posted by medliorator on February 13, 2009

Participants 54 362 women with infertility problems referred to all Danish fertility clinics during 1963-98. 

Main outcome measure Effect of four groups of fertility drugs (gonadotrophins, clomifene citrate, human chorionic gonadotrophin, and gonadotrophin releasing hormone) on overall risk of ovarian cancer after adjustment for potential confounding factors.

Results Analyses within cohort showed no overall increased risk of ovarian cancer after any use of gonadotrophins (rate ratio 0.83, 95% confidence interval 0.50 to 1.37), clomifene (1.14, 0.79 to 1.64), human chorionic gonadotrophin (0.89, 0.62 to 1.29), or gonadotrophin releasing hormone (0.80, 0.42 to 1.51). Furthermore, no associations were found between all four groups of fertility drugs and number of cycles of use, length of follow-up, or parity.

Conclusion No convincing association was found between use of fertility drugs and risk of ovarian cancer.

Use of fertility drugs and risk of ovarian cancer: Danish population based cohort study [BMJ]

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Teratology Fact Sheets

Posted by medliorator on February 12, 2009

The Organization of Teratology Information Specialists has compiled Fact Sheets for a variety of exposures that may impact fertility, fetal development, and lactation. Fact Sheets have been designed to print on a single double-sided page.   Many are available in Spanish.

Topics:

  • Medications
  • Herbal Products
  • Infections and Vaccines
  • Maternal Medical Conditions
  • Illicit Substances
  • Other Common Exposures

OTIS Fact Sheets [OTIS]

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New Data Compare Aliskiren & HCTZ

Posted by medliorator on January 25, 2009

The new direct renin inhibitor aliskiren (Tekturna, Novartis)—when given as first-line monotherapy—reduced blood pressure to a greater degree than one of the usually recommended first-line agents, hydrochlorothiazide, in a new year-long study of patients with essential hypertension. The results were published online January 12, 2009 in Circulation

Schmieder and colleagues randomized 1124 patients with essential hypertension (mean diastolic BP, 95 to 109 mm Hg) to aliskiren 150 mg (n=459), hydrochlorothiazide 12.5 mg (n=444), or placebo (n=221) once daily. Forced titration (to 300 mg for aliskiren or 25 mg for hydrochlorothiazide) occurred at week three; at week six, patients receiving placebo were reassigned (1:1 ratio) to aliskiren 300 mg or to hydrochlorothiazide 25 mg. From week 12, the calcium channel blocker amlodipine 5 mg was added and titrated to 10 mg from week 18 for patients whose BP remained uncontrolled.

At the end of the monotherapy period, aliskiren 300 mg was superior to hydrochlorothiazide 25 mg in reducing BP (-17.4/-12.2 vs -14.7/-10.3 mm Hg; p<0.001).

Criticisms include the fact that the study looked only at a surrogate end points (i.e., mm Hg), and that hydrochlorothiazide is not the ideal comparator. Despite the fact that it is the most commonly prescribed antihypertensive drug, there is little evidence that it favorably affects clinical outcomes, said Dr Franz Messerli (St Luke-Roosevelt’s Hospital, New York). Also, most hypertension patients are controlled on at least two agents, which makes the comparison of monotherapies somewhat futile, said Cockcroft.

New Data on Aliskiren Provoke Debate [HeartWire]

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Smoking Cessation Meta-Analysis

Posted by medliorator on January 23, 2009

CMAJ.  2008; 179(2):135-44

We performed a meta-analysis to compare the treatment effects of 7 approved pharmacologic interventions for smoking cessation.

RESULTS: Six of the 7 pharmacotherapies studied were found to be more efficacious than placebo: varenicline (odds ratio [OR] 2.41, 95% credible interval [CrI] 1.91-3.12), nicotine nasal spray (OR 2.37, 95% CrI 1.12-5.13), bupropion (OR 2.07, 95% CrI 1.73-2.55), transdermal nicotine (OR 2.07, 95% CrI 1.69-2.62), nicotine tablet (OR 2.06, 95% CrI 1.12-5.13) and nicotine gum (OR 1.71, 95% CrI 1.35-2.21)… In our analysis of data from the varenicline trials that included bupropion control arms, we found that varenicline was superior to bupropion (OR 2.18, 95% CrI 1.09-4.08).

INTERPRETATION: Varenicline, bupropion and the 5 nicotine replacement therapies were all more efficacious than placebo at promoting smoking abstinence at 6 and 12 months.

Pharmacotherapies for smoking cessation: a meta-analysis of randomized controlled trials [Medscape]

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Cosmetic Eyelash Drug Approved

Posted by medliorator on January 16, 2009

The Food and Drug Administration (FDA) has green-lighted Latisse, which lengthens, thickens and darkens eyelashes when dabbed daily on the lash line on the lids with a disposable wand.

The med, called Latisse, should be available by March from a doctor or with a prescription from one. Price tag: $120 for a month’s supply.

The active ingredient in Latisse is bimatoprost, a compound derived from fatty acids that bind to receptors in the eyelashes that may be involved in the development and re-growth of hair follicles. Allergan has used bimatoprost since 2001 in Lumigan, an Rx eye drop that lowers eye pressure in people with glaucoma.

Latisse: New eyelash-lengthening drug approved [Scientific American]

Posted in News, Pharmacology | 2 Comments »

Allhat Repercussions

Posted by medliorator on January 2, 2009

Andrew Pollack:

Allhat [Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial] began enrolling patients with high blood pressure, age 55 and older, in 1994, with more than 42,000 people eventually participating. Patients were randomly assigned one of four drugs: a diuretic called chlorthalidone; an ACE inhibitor called lisinopril, which AstraZeneca sold as Zestril; a calcium channel blocker, amlodipine, sold by Pfizer as Norvasc; and an alpha blocker, doxazosin, which Pfizer sold as Cardura.

In the primary target outcome of the trial — the prevention of heart attacks — the three remaining drugs [chlorthalidone, lisinopril, amlodipine] were proved equal. But patients receiving the Norvasc [amlodipine] calcium channel blocker from Pfizer had a 38 percent greater incidence of heart failure than those on the diuretic. And those receiving the ACE inhibitor from AstraZeneca had a 15 percent higher risk of strokes and a 19 percent higher risk of heart failure.

Moreover, the diuretic cost only about $25 a year, compared with $250 for an ACE inhibitor and $500 for a calcium channel blocker. So the diuretic was declared the winner.

The percentage of hypertension patients receiving a diuretic rose to around 40 percent in the year after the Allhat results were announced, up from 30 to 35 percent beforehand, according to some studies. But use of diuretics has since stayed at that plateau. And over all, use of newer hypertension drugs has grown faster than the use of diuretics since 2002

A confluence of factors blunted Allhat’s impact. One was the simple difficulty of persuading doctors to change their habits. Another was scientific disagreement

Even before Allhat was finished, and certainly since then, new drugs appeared. Others, meanwhile, became available as generics, reducing the cost advantage of the diuretics. And many doctors have shifted to using two or more drugs together, helped by pharmaceutical companies that offer combination pills containing two medicines.

So Allhat’s main query — which drug to use first — became “an outdated question that doesn’t have huge relevance to the majority of people’s clinical practices,” said Dr. John M. Flack, the chairman of medicine at Wayne State University

The Minimal Impact of a Big Hypertension Study [NYT]

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Prescribing Placebos

Posted by medliorator on October 27, 2008

679 physicians (57%) responded to the survey. About half of the surveyed internists and rheumatologists reported prescribing placebo treatments on a regular basis (46-58%, depending on how the question was phrased). Most physicians (399, 62%) believed the practice to be ethically permissible. Few reported using saline (18, 3%) or sugar pills (12, 2%) as placebo treatments, while large proportions reported using over the counter analgesics (267, 41%) and vitamins (243, 38%) as placebo treatments within the past year. A small but notable proportion of physicians reported using antibiotics (86, 13%) and sedatives (86, 13%) as placebo treatments during the same period. Furthermore, physicians who use placebo treatments most commonly describe them to patients as a potentially beneficial medicine or treatment not typically used for their condition (241, 68%); only rarely do they explicitly describe them as placebos (18, 5%).

Prescribing “placebo treatments”: results of national survey of US internists and rheumatologists [BMJ]

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Vioxx Risks Confirmed

Posted by medliorator on October 14, 2008

A long-term analysis of people who took the arthritis drug Vioxx confirms it doubles the risk of strokes and heart attacks, researchers said on Monday, but this risk goes away a year after people stop taking it.

Safety data from this same study in 2004 set off alarms that Vioxx increased the risks of heart attacks and stroke, prompting drug maker Merck & Co Inc to withdraw the popular painkiller from the market.

People who took Vioxx in the study had about the double the risk of having a heart attack or stroke than those who took [placebo]

Bresalier said a number of studies since the initial safety warning on Vioxx suggest other Cox-2 inhibitors, including Pfizer Inc’s Celebrex, or celecoxib, and non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen, also carry a higher risk of heart trouble.

Long-term study confirms Vioxx heart risks [Reuters]

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