Download PRC&LRC

Pregnancy
Risk
Categories
(PRC) – FDA
The FDA (USA) has established 5 categories
to indicate the potential of systematically
absorbed drug for causing birth defects. The
key differentiation among the categories
rests upon the reliability of documentation
and the risk:benefit ratio (Lacy et al., 1998).
A
B
C
D
X
Thalidomide (1957 – 1961)
PRC A: Controlled studies in pregnant women fail to
demonstrate a risk to the fetus in the first trimester with
no evidence of risk in later trimesters. The possibility of
fetal harm appears remote.
Examples: Folic acid, T4, Magnesium sulfate (inj.!)
PRC B: The animal-reproduction studies have not
demonstrated a fetal risk but there are no controlled
studies in pregnant women, or animal-reproduction
studies have shown an ARs (other than a decrease in
fertility) that was not confirmed in controlled studies in
women in the first trimester and there is no evidence
of later trimesters. Examples: penicillins, erythromycin,
paracetamol, lidocaine.
PRC C: The studies in animals have revealed ARs
on the fetus (teratogenic, embryocidal or other effects)
and there are no controlled studies in women, or studies
in women are not available. Drug should be given only
if the potential benefits justify the potential risk to the fetus.
Examples: atropine, adrenaline, thiopental, bisoprolol.
PRC D: There is positive evidence of human fetal risk,
but the benefits from use in pregnant women may be
acceptable despite the risk (e.g. if the drug is needed in
a life-threatening situation or for a serious disease for
which safer drugs cannot be used are ineffective.).
Examples: phenytoin, valproate, diazepam, cyclophosphamide.
PRC X: Studies in animals or human beings have
demonstrated fetal abnormalities or there is evidence
of fetal risk based on human experience, or both, and
the risk of the use of the drug in pregnant women clearly
outweighs any possible benefit. The drug is contraindicated in women who are or may become pregnant.
Examples: thalidomide, estrogens,
isotretionoin, ergometrine.
Lactation Risk Categories – LRC)
LACTATION RISK CATEGORIES (LRC) (Hale, 2004; 2008):
L1 – safest: Paracetamol, Ibuprofen, Epinephrine.
L2 – safer: Diclofenac, Fentanyl, Cetirizine,
Omeprazole, cephalosporins.
L3 – moderately safe: Acarbose, Acetylsalicylic acid,
Indometacin, Codeine, Morphine, Midazolam, Triazolam,
Acebutоlol, Dimetinden.
L4 – hazardous: Colchicine, Lithium, Ergobrevine,
Ergotamine.
L5 – contraindicated: ACE inhibitors (enalapril etc.)
Goodman & Gilman's The Pharmacologic
Basis of Therapeutics - 11th Ed. (2006)
PRCs
A: controlled studies
show no risk
B: no evidence of risk in
humans
C: risk cannot be ruled
out
D: positive evidence of
risk
X: contraindicated in
pregnancy
LRCs
L1: safest
L2: safer
L3: moderately safe
L4: possibly hazardous
L5: contraindicated