Antidepressants Hardly Help

admin — Thu, 18 Sep 2008 08:39:35 +0000

Popular antidepressants including Prozac and Paxil have little impact on most patients, according to a comprehensive review of newly released data from trials that were conducted before the drugs were approved in the U.S.
Researchers from the U.K., U.S. and Canada analyzed results for fluoxetine (better known by the brand name Prozac), venlafaxine (Effexor), nefazodone (Serzone) and paroxetine (Paxil or Seroxat) — all members of a class of drugs known as selective serotonin reuptake inhibitors (SSRIs). The researchers’ paper, published this week in the journal PLoS Medicine, claims that only patients who are diagnosed “at the upper end of the very severely depressed category” get any meaningful benefit from the widely prescribed drugs. For the others, the paper says, antidepressants are barely more effective than a placebo (although patients suffering from depression, like those suffering from chronic pain, generally do see a substantial placebo benefit).
There are plenty of studies about antidepressants. What makes this one so important — the results were front-page news across the U.K. on Tuesday — is that the researchers were able to track down comprehensive unpublished trial results from the drug makers themselves before the drugs were authorized for sale in the U.S., and include them in their review of the literature. The U.S. Food and Drug Administration (FDA) must receive records of all relevant pharmaceutical-company trials, both published and unpublished, before it will approve a drug. Under the Freedom of Information Act, the researchers writing in PLoS Medicine were recently able to obtain those FDA records of industry-sponsored clinical trials. They yield data, they believe, that lets them avoid a bias that often plagues reviews of previous research: the tendency for conclusive positive results to be published, sometimes more than once, and thus over-represented, while mediocre results can be ignored or even swept under the rug.
Drug companies claim the review is still flawed, however. One massive problem: there are many more recent studies than those surveyed in the article, which looked only at pre-approval trials conducted before 1999. Nicholas Francis, a U.K. spokesman for Eli Lilly and Company, which produces Prozac, says that the new study “does not take into account that today more than 12,000 patients have participated in Prozac clinical trials and thousands of scientific papers have referenced Prozac, supporting its use in the treatment of depression.” Some 50 million people worldwide have taken Prozac, and in a company statement Lilly said it “is proud of the difference Prozac has made to millions of people living with depression.” Similarly, paroxetine producer GlaxoSmithKline warns, “This analysis has only examined a small subset of the total data available … and this one study should not be used to cause unnecessary alarm and concern for patients.” As a spokeswoman for Wyeth, Effexor’s maker, points out, these were, after all, the same data the FDA reviewed before approving the drugs for public use.
There are really two issues at the heart of the controversy. One is the difference between “statistical significance” — a measure of whether the drug’s effects are reliable, and that patient improvement is not just due to chance — and “clinical significance,” whether those effects actually are big enough to make a difference in the life of a patient. The researchers behind this new paper did find that SSRI drugs have a statistically significant impact for most groups of patients: that is, there was some measurable impact on depression compared to the placebo effect. “But a very tiny effect may not have a meaningful difference in a person’s life,” says Irving Kirsch, lead author on the paper and a professor of psychology at the University of Hull in England. As it happens, only for the most severely depressed patients did that measurable difference meet a U.K. standard for clinical relevance — and that was mostly because the very depressed did not respond as much to placebos. The drug trials showed SSRI patients improved, on average, by 1.8 points on the Hamilton Depression Rating Scale, a common tool to rate symptoms such as low mood, insomnia, and lack of appetite. The U.K. authorities use a drug-placebo difference of three points to determine clinical significance.
The more troubling question concerns what kind of data is appropriate for analyzing a drug’s efficacy. The companies are correct in claiming there is far more data available on SSRI drugs now than there was 10 or 20 years ago. But Kirsch maintains that the results he and colleagues reviewed make up “the only data set we have that is not biased.” He points out that currently, researchers are not compelled to produce all results to an independent body once the drugs have been approved; but until they are, they must hand over all data. For that reason, while the PLoS Medicine paper data may not be perfect, it may still be among the best we’ve got.

By LAURA BLUE/LONDON Tuesday, Feb. 26, 2008
Source: http://www.time.com/time/health/article/0,8599,1717306,00.html?iid=sphere-inline-bottom

Paxil

admin — Sun, 14 Sep 2008 10:16:44 +0000

Paroxetine – Brand Name: Paxil

Overview
Paxil is the brand name for Paroxetine, a phenylpiperidine derivative. Paxil is an SSRI – Selective Serotonin Reuptake Inhibitor, which is a type of antidepressant. SSRIs work by increasing levels of serotonin (a neurotransmitter) to normal.

Paxil’s effects can usually be felt within one to four weeks.

Why is this drug prescribed?
Paxil is used primarily to treat Obsessive-Compulsive Disorder (OCD.)

Paxil is also used to treat:
depression
panic disorder / panic attacks
diabetic nerve pain (neuropathy)
chronic tension headaches
social anxiety disorder (social phobia)
premature ejaculation
premenstrual syndrome (PMS)

Warnings
The safety and effectiveness of Paxil in children under 18 years old have not been established.

Paxil is not addictive. Suddenly discontinuing Paxil may lead to withdrawal symptoms such as confusion, dizziness, sweating, or tremors. Dosage should be gradually tapered when Paxil is discontinued.

Paxil does not usually cause sedation, but patients should not drive or operate heavy machinery until it is known that Paxil does not affect the ability to safely engage in these activities.

For Pregnant or Nursing Mothers: One study showed no adverse effects due to Paxil during pregnancy, but further study is required and pregnant women are not advised to take Paxil. Paxil passes into human breast milk, and nursing mothers should not take Paxil.

Contraindications
Paxil should Not be used for people with an allergy or hypersensitivity to this drug or any SSRI.

Precautions
Paxil may be used with caution in people with the following conditions:
liver or kidney disease – lower dosage may be needed
seizures (epilepsy or convulsions) – risk of seizures is increased
a history of mania – Paxil may activate mania
elderly – lower dosage may be needed
brain disease or damage
mental retardation

Adverse Reactions
Paxil may cause the following reactions:
lowered blood pressure and fainting upon standing (postural hypotension)
sweating
dry mouth
nausea
headache
drowsiness
sedation
nervousness
insomnia
constipation
weakness
loss of appetite
taste disorders
tingling in hands
upset stomach
dizziness
blurred vision
itching
chills
abnormal ejaculation
impotence
sexual dysfunction
diarrhea
hypomania
seizures

Interactions with Drugs and Other Substances
Drugs or substances that may interact with Paxil are:
MAO Inhibitors (within 14 days) – serious or even fatal interactions can occur when taken with Paxil
benzodiazepines, desipramine, Haldol (haloperidol), and Normodyne (labetalol) – Paxil may increase the effects of these drugs
Dilantin (phenytoin) – can decrease blood levels of Paxil and reduce its effects
Quinaglute (quinidine) and Tagamet(cimetidine) – can increase Paxil levels and lead to drug toxicity
Astemizole (Hismanal) – can lead to a serious change in heart rhythm when taken with Paxil
Ultram (tramadol) – can increase the risk of seizures when taken with Paxil
Tryptophan – can increase side effects such as sweating, nausea, and dizziness when taken with Paxil
Coumadin (warfarin) – can cause bleeding when taken with Paxil
Moclobemide (Manerex) within 3 to 7 days
Buspirone (BuSpar), Bromocriptine (Parlodel), Dextromethorphan (cough medicine), Levodopa (Sinemet), Lithium, Meperidine (Demerol), Nefazodone (Serzone), Pentazocine (Talwin), other SSRIs (such as: Citalopram [Celexa], fluoxetine [Prozac], fluvoxamine [Luvox], sertraline [Zoloft]), LSD, MDMA (ecstasy), marijuana, Sumatriptan (Imitrex), Tramadol (Ultram), Trazodone (Desyrel), Tryptophan, Venlafaxine (Effexor) – taking these medicines with Paxil can increase the chance of developing a rare, but very serious, unwanted effect known as the serotonin syndrome, whose symptoms include confusion, diarrhea, fever, poor coordination, restlessness, shivering, sweating, talking or acting with excitement you cannot control, trembling or shaking, or twitching.

Source: http://whatmeds.stanford.edu/medications/paroxetine.html

Psychiatric Drugs »» Antidepressants | Antipsychotics | Antianxiety | Antimanic Agents | Stimulants | Prescription Drugs » SSRI

Antidepressants Hardly Help

Paxil