Pregnancy Risk Categories (PRC)

Pregnancy Risk Categories (PRC)

1. A
B
C
D
X
PregnancyPregnancy
RiskRisk
CategoriesCategories
(PRC) – FDA(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).

2. Thalidomide (1957 – 1961)

3. 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.

4. 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.

5. Sponsored
Medical Lecture Notes – All Subjects
USMLE Exam (America) – Practice

6. 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 contraindi-
cated in women who are or may become pregnant.
Examples: thalidomide, estrogens,
isotretionoin, ergometrine.

7. Lactation Risk Categories – LRC)Lactation Risk Categories – LRC)

8. L1 – safest: Paracetamol, Ibuprofen, Epinephrine.
LACTATION RISK CATEGORIES (LRC) (Hale, 2004; 2008):
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.)

9. PrregnacycPRignaskcCtoc(tn)gn rir–R
FnkRkcrDcCto)nAoThR kclcddhtcme1c95776: Goodman & Gilman's The Pharmacologic
Basis of Therapeutics - 11th Ed. (2006)

10. PRCsPRCs LRCsLRCs
AA:: controlled studies controlled studies
show no riskshow no risk
BB:: no evidence of risk in no evidence of risk in
humanshumans
CC:: risk cannot be ruled risk cannot be ruled
outout
DD:: positive evidence of positive evidence of
riskrisk
XX:: contraindicated in contraindicated in
pregnancypregnancy
L1L1:: safest safest
L2L2:: safer safer
L3L3:: moderately safe moderately safe
L4L4:: possibly hazardous possibly hazardous
L5L5:: contraindicated contraindicated