HIV TREATMENTS have been remarkably effective
over the years in managing the disease, thanks
largely to clinical trials. Yet one significant risk
group typically falls outside the realm of these
trials: pregnant women and their unborn children.
Though mother-to-child transmission is now the
most common route of HIV infection, the proper
dosage of treatments remains widely unknown—
too much or too little of the medicine may do both
mother and child more harm than good. Brookie Best,
Revelle ’94, M. A.S. ’07, devotes her work as a UC San
Diego professor of clinical pharmacy and pediatrics
to researching where the balance may lie.
Dosages for pregnant women and children are often
scaled down from standard doses at a “best-guess”
approach. Yet the metabolization of a drug varies
widely across bodies, due to factors such as age,
weight, hormones and more.
“We find that for nearly every drug, pregnancy alters
the way the drug is absorbed and eliminated in the
body,” says Best. “And as these women get further
along in their pregnancies, they’re taking the same
drug dose as was initially given, so the actual
exposure of the drug is dropping lower and lower.
When it matters the most—which is right near
delivery—they might get the highest risk for the
virus to break through or start increasing again,
or even become resistant to the drugs because now
there’s not enough to keep [the virus] down.”
A decreased drug concentration isn’t the only thing
to be worried about—over the duration of a pregnancy,
drug exposure can also increase in strength.
“If you give too low of a concentration, you put the
fetus at risk of acquiring HIV. If concentrations are
too high, you could put both mother and baby at
risk for toxicity.”
Incorporating pregnant women into clinical research
could help find the solution, yet many have excluded
these populations due to ethical conundrums and
the fear of risk. “There’s no right answer,” says Best,
with regards to how to morally include these
populations in medicinal studies. Still, she has found
ways to work through these concerns, while providing
both short- and long-term benefits.
BROOKIE BEST, ’94,
professor of clinical
pharmacy and pediatrics
and associate dean for
admissions and outreach
at the Skaggs School of
Pharmacy and Pharmaceutical Sciences.
Brookie Best, ’94, works to help
HIV’s most vulnerable victims.
BY SHERILYN REUS, ’ 16
“We find that for nearly
every drug, pregnancy alters
the way the drug is absorbed
and eliminated in the body.”