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RISK MANAGEMENT OPTIONS FOR PREGNANCY PREVENTION. Kathleen Uhl, MD Pregnancy Labeling US Food & Drug Administration. Objectives. General principles of a teratogen Decision making regarding pregnancy prevention strategies Existing strategies for pregnancy & fetal exposure prevention.
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RISK MANAGEMENT OPTIONS FOR PREGNANCY PREVENTION Kathleen Uhl, MD Pregnancy Labeling US Food & Drug Administration
Objectives • General principles of a teratogen • Decision making regarding pregnancy prevention strategies • Existing strategies for pregnancy & fetal exposure prevention
Teratogen • What is a teratogen? • An agent or factor that causes: • birth defect or congenital malformation • abnormal development in an exposed embryo or fetus
“Teratogenic Exposure” • Teratogenic potential at clinical doses used in humans • Teratogenic effect is not 100% • Other factors contribute • Genetic susceptibility • If given at a high enough dose even “benign” agents can be teratogenic • Glucose
Developmental Abnormalities • Structural abnormalities • Skeletal or soft tissue malformations • Fetal and infant mortality • Miscarriage, stillbirth, embryolethality • Impairment of physiologic function • Endocrinopathy, deafness, neurodevelopmental effects, impairment of reproduction function • Altered growth • Growth retardation or enhancement, delayed or early maturation
Is a drug a teratogen? • Animal data • Totality of evidence from animals: • Highly suspected human teratogens • Not yet proven to be a human teratogen
Is a drug a teratogen? • Human data • Adverse event reports • Medical literature • Pregnancy exposure registries or other postmarketing studies • Peer reviewed assessments • OTIS, TERIS
Decision MakingTiers of Concern • No or low • Highly suspect teratogens • Known human teratogens • Frequency – high vs. low • Severity • Reversibility • Critical time of exposure
Decision MakingWhat is the Risk? • Frequency of event • Severity of outcome • Not all birth defects are equal • Major congenital anomaly (incompatible with life vs. surgically correctable vs. cosmetic) • Reversibility • Type of abnormality • Structural malformations, mortality, impaired physiologic function, altered growth • Timing of exposure • Severity and type of outcomes affect perception of “badness”
Decision Making Maternal Disease • Does maternal disease increase risk for birth defects (e.g., diabetes)? • What are the consequences of untreated maternal disease (e.g., seizure disorders)? • What are the benefits of treatment?
Warfarin Toxicity well known Risk is relatively low (low rates) Timing 6-9 weeks Use in FCBP low Comprehensive care Isotretinoin Toxicity known +/- Risk is large (high rates) Timing 3-5 weeks Use in FCBP high Targeted care Decision MakingRange of Options
Isotretinoin Teratogenicity • Structural malformations • Craniofacial, cardiac, thymus, CNS • 20-30% exposed fetuses • Functional impairment • Intellectual impairment • Mortality • Increased spontaneous abortion & premature birth • Critical period of exposure • Single dose teratogenic • Unique pharmacokinetics Schardein JL, 2000
Goals of Pregnancy Prevention • Pregnant women do not receive drug • Females of childbearing potential do not get pregnant while taking drug
Label is Most Applied ToolCRF 201.57 • Decision making process considers: • Disease to be treated • Population of intended use • Frequency of event • Severity of event • Benefits of drug use outweigh potential risks • Labeled as Category “D” • Wording in “Warnings” section • Benefits do not outweigh potential risks • Drug should not to be used in pregnancy • Labeled as Category “X” • Wording in “Contraindications” section
Known human teratogen Systemic retinoids (e.g., isotretinoin) Thalidomide Warfarin Antimetabolites (e.g., methotrexate) Testosterone Highly suspect human teratogen Ribavirin Bosentan Statins “Contraindicated” Drugs
Labeling Beyond “X”Informational • Black Box • Must go into all advertising • “Warnings” • Informed Consent • Advised or included • Medication Guide • Required issuance
Labeling Beyond “X”Active Interventions • Pregnancy testing • Contraceptive use Require health care provider and/or patient to actively DO something
PREGNANCY TESTS • Before starting drug • Timing relative to starting drug • Number of tests prior to starting drug • Continued testing during drug therapy • Periodic or specific (monthly) • Testing after completing drug therapy • For how long? • Test specifics • Sensitivity • Urine or Blood • Accredited laboratory vs. doctor’s office vs. home pregnancy testing
CONTRACEPTION • Before starting drug • Timing relative to starting drug • Continued use during drug therapy • Contraception after completing drug therapy • For how long? • Contraception specifics • Acceptable methods, e.g., “primary methods” • Number of methods
ADDITIONAL PREGNANCY PREVENTION STRATEGIES • Limited Supply • Prohibited refills • Links • Real time documentation • Registration • Limited Distribution
Ultimate Pathway to Prevention Patient and prescriber understand the risk and actively work to mitigate it: • Adequately informed of risk • Understand the risk • Demonstrate behavior consistent with risk
Pregnancy Prevention Strategies • Very complex • Not all teratogens are equal • Pregnancy Prevention = prevent fetal exposure • At drug initiation • With continued drug use • Must tailor pregnancy prevention to the specific drug • One size does NOT fit all