Cincinnati—As vacationers head to high-altitude getaways this time
of year, a new study from the University of Cincinnati (UC) College of
Pharmacy found that high altitudes could change the effectiveness of
Wolfgang Ritschel, MD, PhD, professor
emeritus of pharmakinetics at UC, and researchers at the University of
Chile in Santiago conducted the study, which was funded by the United
States Fulbright Commission. The study investigated the effectiveness
of Demerol, lithium, and acetazolamide on 36 males who either live at
sea level and travel to high altitudes or live in high altitudes.
high altitudes, our bodies produce more red blood cells," says
Ritschel. "All three drugs examined bind these cells. With an increase
in red blood cells, the amount of the medication that attaches to each
cell is increased. Hence the amount of free drugs in plasma is reduced,
lessening the effectiveness of the medication."
reaction occurs with drugs that bind to plasma proteins. Our bodies
produce less plasma proteins in high altitude. Plasma proteins decrease
in high altitudes, explains Ritschel. Therefore, more free medication
is available in the plasma, increasing the effectiveness of the drug.
The increased potency of the drug could even turn toxic in high
altitudes. High altitudes also affect the distribution of water in the
body and the pH level of body fluids, which can also alter the
effectiveness of medications.
According to Ritschel, "Research on
the body’s reaction to medication is generally done on subjects who
live at sea level, and these results are extrapolated to people at high
altitudes. This study suggests that a dosage's clinical effectiveness
should also be tested on people in high altitudes."