Molecule of amantadine
Find information on thousands of medical conditions and prescription drugs.

Symmetrel

Amantadine, 1-aminoadamantane, is an antiviral drug that was approved by the FDA in 1976 for the treatment of influenza type A in adults. The drug has also been demonstrated to help reduce symptoms of Parkinson's disease and drug-induced short-term extrapyramidal syndromes. As an antiparkinsonic it is being prescribed together with L-DOPA when L-DOPA responses decline (probably due to tolerance). Amantadine has been shown to cure SSRI-induced anorgasmia in some people, though not in all people. more...

Home
Diseases
Medicines
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
Growth hormone
Salbutamol
Salmeterol
Sandimmune
Sandostatin
Sansert
Saquinavir
Sarafem
Satric
Scopolamine
Seasonale
Secobarbital
Secretin
Selegiline
Semprex-D
Sensipar
Sensorcaine
Serax
Serevent
Serine
Seroquel
Serostim
Serrapeptase
Sertindole
Sertraline
Serzone
Sevelamer
Sevoflurane
Sibutramine
Sildenafil
Silibinin
Simvastatin
Sinemet
Sinequan
Singulair
Sirolimus
Skelaxin
Sodium cyclamate
Solage
Soma
Somatostatin
Sotahexal
Sotalol
Sotret
Spiperone
Spiriva
Spironolactone
Sporahexal
Sporanox
SPS
SSD
Stanozolol
Stavudine
Stelazine
Stilbestrol
Stilbetin
Stimate
Stiripentol
Strattera
Streptokinase
Streptomycin
Suboxone
Subutex
Sucralfate
Sucralfate
Sufentanil
Sulbactam
Sulfamethoxazole
Sulfanilamide
Sulfasalazine
Sulforidazine
Sulla
Sulpiride
Sultamicillin
Sumatriptan
Suprefact
Suramin sodium
Sustaire
Sustiva
Suxamethonium chloride
Symmetrel
Synarel
Synercid
Synthroid
Syntocinon
Zaleplon
T
U
V
W
X
Y
Z

It is a derivate of adamantane, like a similar drug rimantadine.

Availability

It is available as a prescription drug as a generic drug and under brand name Symmetrel.

Mechanism of its effects

The mechanism of its antiparkinsonic effect is not fully understood, but it appears to be releasing dopamine from the nerve endings of the brain cells, together with stimulation of norepinephrine response.

The antiviral mechanism seems to be unrelated. The drug interferes with a viral protein, M2 (an ion channel), which is needed for the viral particle to become "uncoated" once it is taken inside the cell by endocytosis.

Misuse

Recently, amantadine is reported to have been used in China poultry farming in an effort to protect the birds against avian flu. In western countries and according to international livestock regulations, amantadine is approved only for use in humans. Chickens in China have received an estimated 2.6 billion doses of amantadine. Avian flu (H5N1) strains in China and southeast Asia are resistant to amantadine, but strains circulating elsewhere seem to be sensitive. If amantadine resistant strains of the virus spread, the drug of choice in an avian flu outbreak will likely be restricted to one of the scarcer and costlier oseltamivir or zanamivir, which work by a different mechanism and are less likely to trigger resistance.

Read more at Wikipedia.org


[List your site here Free!]


HHS focuses on flu pandemic preparedness plan
From OB/GYN News, 5/1/05 by David Sternberg

BALTIMORE -- Acknowledging that "flu has a huge news factor," Bruce Gellin, M.D., spelled out the federal influenza pandemic preparedness plan at a biodefense research meeting sponsored by the American Society for Microbiology.

The Department of Health and Human Services' draft Pandemic Influenza Response and Preparedness Plan, developed in August 2004, includes influenza control, stockpiling vaccines, developing antiviral drugs and prophylaxis, providing quality medical care, and maintaining community services, said Dr. Gellin, director of the National Vaccine Program Office, a division of HHS. The World Health Organization originally developed pandemic preparedness guidelines in 1999 for other organizations to follow.

"There are a lot of unknowns," said Dr. Gellin. "When will a pandemic occur? How bad will it be? And will there be major social and economic fallout? We need to continue to identify unmet questions."

Improving vaccine preparedness is a major focus of the HHS plan. To that end, Dr. Gellin said the United States must enhance annual influenza vaccine use, ensure a year-round egg supply, increase and diversify U.S. manufacturing capacity, and improve the ability to rapidly develop reference strains.

As for antiviral drugs, the U.S. government currently stockpiles 2 million doses of Tamiflu (oseltamivir) and 4 million doses of Flumadine (rimantadine). He acknowledged the need for a greater stockpile of these drugs, as well as a push for other therapies besides antivirals.

Even in the case of a mild pandemic, Dr. Gellin emphasized the heightened need for inpatient medical services and effective triaging of patients, noting there would be an estimated 25% increase in demand for inpatient beds, ICU beds, and ventilators.

A few key issues remain unresolved, according to Dr. Gellin, including determining priority groups for early vaccine and antiviral use in the event of a pandemic; purchase and distribution of public- and private-sector vaccinations; and legal issues, including indemnification, liability protection, and compensation.

Two other significant issues addressed in the pandemic plan are development of new vaccines and therapeutics.

Richard J. Webby, Ph.D., of St. Jude Children's Hospital in Memphis, pointed out the many considerations for creating a vaccine in response to an emerging influenza pandemic.

"There is no way of accurately predicting what strain it might be; there is enormous diversity of viruses in animal reservoirs, and some viruses are highly pathogenic," he said.

But a procedure called reverse genetics has been significant in Dr. Webby's work at St. Jude's in accelerating the development of vaccines. Reverse genetics begins with a cloned segment of DNA and introduces programmed mutations back into the genome to investigate gene and protein function.

As for antivirals, the existing therapeutics are M2 ion channel inhibitors and neuraminidase inhibitors (NAIs), said Simon P. Tucker, Ph.D., of Biota Holdings Ltd., in Melbourne, Australia.

The M2s are Symmetrel (amantadine) and Flumadine, both of which are dosed at 100 mg twice a day. The NAIs are Relenza (zanamivir) and Tamiflu. Relenza is dosed at 10 mg twice daily and Tamiflu at 75 mg twice daily, said Dr. Tucker.

There are some basic differences between the two drug classes, Dr. Tucker said. M2s are used only for influenza A and have a high clinical resistance; NAIs are effective against both influenza A and B and have a low clinical resistance.

For these reasons, NAIs, particularly Tamiflu, are prescribed more often than M2s, he said. Most prescriptions are written by family physicians; most of the patients are aged 20-59 years, he said.

Dr. Tucker noted that another drug class is under development--long-acting neuraminidase inhibitors (LANIs)--and has exhibited some early success.

One LANI monomer (R-118958) has shown to be more potent and more effective than Relenza, said Dr. Tucker. He noted a few of the advantages to LANIs: onetime-only therapy, once-weekly prophylaxis, and an optimal use for inter-pandemic cases.

Biota Holdings Ltd. was involved in the development of Relenza and is currently developing LANIs under a contract from the National Institutes of Health.

BY DAVID STERNBERG

Contributing Writer

COPYRIGHT 2005 International Medical News Group
COPYRIGHT 2005 Gale Group

Return to Symmetrel
Home Contact Resources Exchange Links ebay