Meprobamate 267stimulant (nicotine) is taken after a depressant. In contrast, injection ofmari-
juana’s main active component THC increases the power of a meprobamate
dose in animals. Meprobamate has been used in combination withdex-
troamphetaminefor human weight loss, a combination that had uncertain
effectiveness but that produced fewer unwanted actions than dextroamphet-
amine alone. Alcohol and meprobamate each have similar unwanted effects,
and in that regard using both together can be the equivalent of taking extra
doses of one or the other. Among steady drinkers, however, blood levels of
meprobamate decline faster than in nondrinkers, meaning a meprobamate
dose lasts a shorter time in the drinkers. A mice study indicated that poison-
ous effects of meprobamate worsen if either alcohol orphenobarbitalis also
used. Phenobarbital and other barbiturates have cross-tolerance with mepro-
bamate, meaning that the barbiturates can substitute for meprobamate in at
least some respects.
Cancer.Not enough scientific information to report.
Pregnancy.Meprobamate administered into chicken eggs results in embryo
malformations, and skeletal deformity has been observed with fetal develop-
ment in rats exposed to the compound. The drug passes into a human fetus.
A study of over 50,000 pregnancies, including many women who used mepro-
bamate, found no evidence of birth defects linked to the drug, findings du-
plicated by another analysis of outcomes in more than 6,000 pregnancies.
Nonetheless, meprobamate is suspected of causing birth defects. Indeed, in a
study of almost 20,000 pregnancies, birth defects were over twice as common
among women using meprobamate during early pregnancy than among
women who used other antianxiety drugs and more than four times as com-
mon compared to women who took no drug at all in early pregnancy. One
study found that congenital heart lesions occurred more often if meprobamate
was used during pregnancy. Rats with fetal exposure to meprobamate show
learning difficulties, and tests of five-year-old children who had prenatal ex-
posure to the substance reveal impaired reasoning ability. The meprobamate
level in milk of nursing mothers has been measured as up to four times higher
than the level in their blood.
Additional scientific information may be found in:
Carson, J. “Meprobamate Revisited.”New York State Journal of Pharmacy2 (1989):
45–46.
Gomolin, I. “Meprobamate.”Clinical Toxicology18 (1981): 757–60.
Greenblatt, D.J., and R.I. Shader. “Meprobamate: A Study of Irrational Drug Use.”
American Journal of Psychiatry127 (1971): 1297–1303.
Logan, B.K., G.A. Case, and A.M. Gordon. “Carisoprodol, Meprobamate, and Driving
Impairment.”Journal of Forensic Sciences45 (2000): 619–23.
McNair, D.M. “Antianxiety Drugs and Human Performance.”Archives of General Psy-
chiatry29 (1973): 611–17.
“Meprobamate.”Medical Letter on Drugs and Therapeutics7 (1965): 36.