Overview: When is a muscle relaxant not a muscle
relaxant? When it’s Soma®. Then it’s a tranquilizer, too,
and a possible prescription for trouble. That’s because Soma
is a chemical chameleon, one that morphs in the human body from
chemical caterpillar into biological bee — and it can sting.
For starters, Soma is literally two drugs in one. The first,
carisoprodol (its generic name), is a muscle relaxant
— or at least, it starts out that way. Then, as it breaks down
in the body, it morphs into a different drug altogether: meprobamate.
Never heard of it? No wonder. When it was introduced in 1955,
under the trade name Miltown®, meprobamate was a pharmaceutical
superstar, the first “minor” tranquilizer, thought
to be addiction- and overdose-free. But a funny thing happened
on its way into history: It turned out to be neither.
Appearance: Brand-name Soma® is a white tablet,
with “Wallace 2001” imprinted on one side. Generic
and foreign forms of carisoprodol vary.
Medical Uses: Carisoprodol is used to treat muscle
spasms and strains, usually combined with physical therapy, exercise,
and rest. Meprobamate is still occasionally used to treat anxiety,
but has mostly been replaced by benzodiazepine tranquilizers,
for safety reasons.
Actions/Effects: Carisoprodol blocks specific nerve impulses,
while meprobamate reduces anxiety. Effects are similar to those
of alcohol, and include feelings of relaxation, dizziness, and
euphoria, depending on dosage.
Side Effects: Adverse reactions involve drowsiness,
tremor, headache, and unconsciousness. Allergic reactions include
rash, itching, asthma attacks, fever, and shock.
Overdose: A main reason that Miltown fell from
favor so fast was its potential for overdose, particularly when
used with alcohol and other depressants. Since tolerance to meprobamate’s
depressant effects can set in before tolerance to carisoprodol’s
muscle-relaxant properties, overdose symptoms (which include
fainting, slowed breathing, and unconsciousness) are serious,
and should be regarded as a life-threatening emergency.
Trends: Soma emerged as a drug of choice due to its easy
availability via offshore Internet pharmacies and its status,
until recently, as an unregulated controlled substance. It is
currently listed as a Schedule IV controlled substance by 19
states, and its reclassification as a controlled substance is
pending on a federal level.
Demographics: Since carosiprodol isn’t considered
a “recreational” drug, there are few numbers available
to chart its spread. Still, it consistently ranks near the top
on lists of drugs that often cause overdose and adverse reactions.
In 2009, it figured into 4,761 U.S. emergency-room admissions,
according to the Drug Abuse Warning Network.