Risk Factors (A, B, C, D, X)
have been assigned to all drugs, based on the level of risk the drug poses to
the fetus. Risk Factors are designed to help the reader quickly classify a drug
for use during pregnancy.
They do not refer to
breast-feeding risk. Because they tend to oversimplify a complex topic, they
should always be used in conjunction with the Fetal Risk Summary. The
definitions for the Factors are those used by the Food and Drug Administration
(Federal Register 1980;44:37434-67).
Since most drugs have not yet
been given a letter rating by their manufactures, the Risk Factor assignments
were usually made by the authors. If the manufacturer rated its product in its
professional literature, the Risk Factor on the monograph will be shown with a
subscript M (e.g., CM).
If the manufacturer and the
authors differed in their assignment of a Risk Factor, our Risk Factor is marked
with an asterisk and the manufacture’s rating is shown at the end of the amides,
morphine, etc.) are drugs that present different risks to the fetus, depending
on when or for how long they are used. In these cases, a second Risk Factor will
be found with a short explanation at the end of the Fetal Risk Summary. We hope
this will increase the usefulness of these ratings. The definitions used for the
Risk Factors are presented below.
| A |
Controlled studies in women fail to demonstrate a risk to the fetus
in the first trimester (and there is no evidence of a risk in later
trimesters), and the possibility of fetal harm appears remote. |
| B |
Either 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 adverse effect (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 a risk in
later trimesters). |
| C |
Either studies in animals have revealed adverse effects on the fetus
(teratogenic or embryocidal, or other) and there are no controlled
studies in women or studies in women and animals are not available.
Drugs should be given only if the potential benefit justifies the
potential risk to the fetus. |
| 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 or are ineffective). |
| 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.
|
| A |
- Ferrous sulphate
- Levothyroxine
- Magnesium sulphate injectable
- Vitamin B1
- Vitamin B6
|
| B |
- Amoxicillin
- Cefaclor
- Cefoperazone
- Cephalexin
- Ceftriaxone
- Cimetidine
- Clindamycin
- Erythromycin
- Famotidine
- Indomethacin
- Isosorbide
- Lactulose
- Methyldopa
- Metronidazole
- Nitrofurantoin
- Prednisone
- Sucralfate
- Spironolactone |
| C |
- Acetaminophen
- Acyclovir
- Adenosine
- Allopurinol
- Aminophylline
- Alcohol
- Amphetamine
- Atropine sulphate
- BCG
- Calcium injectable
- Chloroquine
- Chlorpheniramine maleate
- Chlorpromazine
- Ciprofloxacin
- Clofazimine
- Clonidine
- Clotrimazole
- Dapsone
- Dexamethasone
- Digoxin
- Diltiazem
- Ethionamide
- Furosemide
- Gentamycin
- Haloperidol
- Heparin Calcium
- Hydralazine
- Interferon Alpha
- Isoniazid
- Ketoconazole
- Levodopa
- Mannitol
- Mefenamic Acid
- Mefloquine
- Neostigmine
- Nifedipine
- Norfloxacin
- Prazosin
- Rifampicin
- Streptokinase
- Vitamin K
- Zidovudine
|
| D |
- Alprazolam
- Amikacin Sulphate
- Amiodarone
- Amitriptyline
- Aspirin
- Atenolol
- Captopril
- Colchicine
- Doxycycline
- Enalapril maleate
- Eosinopril
- Kanamycin
- Lisinopril
- Lorazepam
- Neomycin
- Netlimicin
- Oxazepam
- Ramipril
- Tamoxifen
- Valproic acid
|
| X |
- Ergotamine tartarate
- Phenobarbital
- Clomiphene citrate
- Danazol
- Ethinyl Estradiol
- Levonorgestrel
- Oxytocin
- Quinine sulphate
- Stanazolol
- Vitamin A
- Warfarin Sodium
|
