Fluoxetine hydrochloride (brand names include Prozac®, Symbyax®
(compounded with olanzapine), Sarafem®, Fontex® (Sweden), Fluctine
(Austria, Germany), Prodep (India), Fludac (India)) is an
antidepressant drug used medically in the treatment of depression,
obsessive-compulsive disorder, bulimia nervosa, premenstrual
dysphoric disorder, and many other disorders. It is a selective
serotonin reuptake inhibitor (SSRI), and is marketed in capsules
containing 10, 20, 40 or 60 mg of active ingredient or in tablets
containing 10 mg. Dosages in the range of 20-60 mg per day are
standard, with 80 mg considered a maximum. Eli Lilly's Prozac was
approved by the FDA on December 27, 1987 and introduced in the US
at the beginning of 1988. The drug became very popular, with
millions around the world having taken the medication.
Fluoxetine has a wide range of published interactions, notably with
monoamine oxidase inhibitors. Common side-effects include anxiety,
restlessness, trembling, weakness, skin rash, anorgasmia, itching,
and a decrease in sexual drive.
Fluoxetine is eliminated very slowly by the body. The half-life of
fluoxetine after a single dose is 2 days and after multiple dosing
4 days. The liver then metabolizes fluoxetine into norfluoxetine, a
desmethyl metabolite, which is also a serotonin reuptake inhibitor;
norfluoxetine has an even longer half-life, i.e. 8.6 and 9.3 days
for single and repeated dosage respectively. Other SSRIs have, by
comparison, a very short half-life - some professionals feel that
it is fluoxetine's long half-life that gives it much of its
therapeutic utility. Fluoxetine is a potent CYP2D6 inhibitor, which
can decrease metabolism of other medications.
In December 2003 the FDA approved Symbyax to treat bipolar
depression. Symbyax is a combination of fluoxetine and
olanzapine.
Controversy
In the late 1990s, a backlash grew against Prozac. Prozac®'s
manufacturer, Eli Lilly and Company, Inc. earned billions from its
success, and became the target of numerous accusations (see David
Healy affair). Lawsuits amounting to millions were instigated,
alleging the drug made users feel suicidal and/or caused other
serious side effects. The accusations and lawsuits have been
unsuccessful in stemming the prescription and use of the
medication, as well as in making the accusers some of Lilly's
profits. Currently, the US FDA is considering similar controversial
issues regarding Prozac® and its use in children and
adolescents.
A more recent controversy embroiled Lilly, and a class action
lawsuit has been filed after several people received in the mail
free samples of Prozac® Weekly. The suit alleges that the samples'
recipients' right to privacy was mishandled.
In August 2004 a report by the Environment Agency found trace
amouts of fluoxetine in UK drinking water, although the Drinking
Water Inspectorate said that it was unlikely to pose a health risk.
However, the effcts from ingestion of fluoxetine in drinking water
has not been investigated.
In January, 2005, the British Medical Journal was leaked official
Eli Lilly documents from the 1980s suggesting the a link between
fluoextine and suicide and psychosis. It was originally claimed
that the documents had not been previously disclosed, and they were
subsequently provided to the FDA for further investigation.
However, Eli Lilly later claimed that the documents had been
released in earlier litigation.[1]
(http://www.prnewswire.com/cgi-bin/micro_stories.pl?ACCT=916306&TICK=LLY&STORY=/www/story/01-05-2005/0002770570&EDATE=Jan+5,+2005)
The British Medical Journal ultimately retracted its claim that the
documents had not been previously disclosed, and apologized to Eli
Lilly.[2]
(http://bmj.bmjjournals.com/cgi/content/full/330/7485/211-a?maxtoshow=)
The resources at the end of this article present a blend of views
on this drug, some of which focus on the more controversial and
unscientific issues.