To  :  Dr. Montgomery
Re  : Marijuana and drugs of abuse.

        This question concerns a mom who has in the past month used
Marijuana(MJ) and wishes to breastfeed.   This is a question that I am
asked almost every week,  particularly from child protective services.
Unfortunately,  its a judgement call that has to be weighed closely.

        First,  marijuana is a very lipid soluble drug, that is sequestered
for long periods of time,  not in the brain,  but in lipid rich(adipose)
tissue of the body.  It produces sedation, decreased aggressive behavior,
and the classic "Amotivational syndrome".  Chronic high dosage produces a
dose related depression of ovarian function,  a decrease in LH and FSH and
anovulatory menstrual cycles;  and in males may reduce
spermatogenesis(lowers testosterone).  Animal studies suggest a decrease in
prolactin production and milk production.

        The elimination half-life is approximately 30 hours,  although
certain metabolites may be longer.  Because MJ metabolites are retained for
long periods in lipid rich tissues, small(but detectible) levels are
excreted for weeks.  Such levels lead to a positive urine screen for at
least 2 weeks,  and maybe a month in chronic high-dose users.

        The milk:plasma ratio is approximately 8,  and it appears that
marijuana is readily transferred into human milk.  We do not know if the
levels are high enough to produce neuroleptic effects in a nursing
infant... I rather doubt they are but this would depend on dose and
temporal factors.  More importantly(legally),  the infant and mom will
continue to test positive on drug screens for some time(even if mom has not
smoked recently),  even though the infant may be only exposed to minuscule
concentrations of MJ.  Thus far,  a number of studies seem to indicate that
there are no long term sequelae from prenatal or postnatal exposure to
marijuana,  although there is room for argument.

        So I generally recommend to Child Protective services,  that mom be
routinely screened for drug abuse(cocaine, MJ, etc.).  Because the process
of breastfeeding is so terribly important for bonding and medical reasons,
I think continued breastfeeding is worth the risk of exposure to small
levels of drugs of abuse(which we know seldom produce pharmacologic
effect).

        So I recommend continued monitoring,  and let the mom breastfeed.
Both she and the infant will probably still be positive for MJ for up to a
month,  but the urine levels should be dropping.  What do you do if the mom
still tests positive for MJ use after one month...use your best judgement,
knowing that the neuroleptic effects of low dose marijuana in the infant
will probably be minimal.

        This is one of those times,  that pharmacologic reasoning should
probably over-rule our emotions, and when the wonders of breastfeeding
significantly outweigh smaller risks of exposure to MJ.

Tom Hale