Ephedrine 143Drug interactions.Caffeine boosts ephedrine’s power and can transform a
normal dose into a dangerous one. Aspirin and yohimbine (fromyohimbe)
may also strengthen some ephedrine effects. Dangerous interactions can occur
with monoamine oxidase inhibitors (MAOIs, typically antidepressants). Less
serious adverse effects may occur if ephedrine is taken with the antiasthma
medicine theophylline.
Cancer.The FDA has noted research indicating that substances like ephed-
rine may promote lung cancer, especially among tobacco smokers.
Pregnancy.Safety for use during pregnancy is unestablished. The drug is
known to raise fetal heart rate, and fetal blood levels can reach about 70% of
the pregnant woman’s blood level of ephedrine. The drug is transferred to
breast milk in sufficient quantity to affect nursing infants, making them
grouchy and interfering with their sleep. Chicken experiments with ephedrine
produce defects in embryos, but such testing is considered inconclusive re-
garding human impact. Rabbit experiments find a mix of ephedrine, theoph-
ylline, andphenobarbitalto cause birth defects similar to those observed in
the child of a woman who took that drug combination while pregnant. The
same drug combination is suspected in another birth defect case. Although a
study of 373 human pregnancies found no malformations attributable to
ephedrine even when used in the first trimester, the drug is associated with
a small increase in likelihood of birth defects and is not recommended for use
during pregnancy.
Additional information.Many nonprescription remedies for common colds
include pseudoephedrine (CAS RN 345-78-8), which is related to ephedrine
and has similar effects, both desired and undesired. Depending on actions
being measured, pseudoephedrine may have from 25% to 50% of ephedrine’s
strength. Pseudoephedrine can be used to make methamphetamine and meth-
cathinone.
Pseudoephedrine is believed to promote a dangerous bowel disease called
ischemic colitis, particularly in women around the time they go into meno-
pause. A case report indicates that taking pseudoephedrine with serotonin
reuptake inhibitor antidepressants may create a medical emergency called “se-
rotonin syndrome.” Typical signs of that condition are hyperactivity, con-
fusion, nervousness, vomiting, fast heartbeat, excessive body temperature,
shivering, tremors, weakness, or losing consciousness. Caution is advised
about using pseudoephedrine shortly after receiving vaccinations, which tem-
porarily increase body temperature. Nonetheless, in the 1980s research on
more than 100,000 individuals using prescription pseudoephedrine found no
hospitalizations caused by the drug.
Influence on fetal development is uncertain, although pseudoephedrine is
suspected of causing birth defects when used in the first trimester. The drug
is known to accelerate fetal heartbeat but has no particular effect on fetal blood
flow, nor does the substance seem to hinder passing nutrients and gases be-
tween woman and fetus. Although excreted into human milk, the amount of
excretion is so slight as to be considered safe for infants of nursing mothers.
Additional scientific information may be found in:
“Adverse Events Associated with Ephedrine-Containing Products—Texas, December
1993–September 1995.”Morbidity and Mortality Weekly Report45 (1996): 689–93.