Pharmacology in Pregnancy & Lactation

Vocabulary flashcards summarising key drugs, supplements, immunologic terms, and safety considerations for pregnancy and lactation.

Rifampin

Enzyme-inducing antibiotic that lowers hormonal contraceptive efficacy.

Carbamazepine

Anticonvulsant that induces CYP enzymes and decreases birth-control effectiveness; teratogenic.

Phenytoin

CYP-inducing antiepileptic that reduces steroid contraceptive levels and is teratogenic (fetal hydantoin syndrome).

Topiramate

Broad-spectrum anticonvulsant that weakens oral contraceptives and may cause cleft palate in fetuses.

Lamotrigine

Antiepileptic preferred in pregnancy and lactation; enzyme induction by OCs can lower its levels.

St. John’s wort

Herbal CYP3A4 inducer that markedly reduces oral contraceptive effectiveness.

Smoking tobacco

Induces hepatic metabolism and decreases estrogen contraceptive efficacy; adds thrombotic risk.

Copper IUD

Most effective emergency contraception; hormone-free and usable up to 5 days after intercourse.

Levonorgestrel (Plan B)

Progestin emergency contraceptive taken within 72 h; efficacy reduced by enzyme inducers.

Folic acid (Vitamin B9)

Supplement started ≥1 month pre-conception to prevent neural tube defects (400–800 µg/day).

Isotretinoin

Acne retinoid absolutely contraindicated in pregnancy; stop ≥1 month before conception (iPLEDGE).

Neostigmine

Myasthenia gravis drug to discontinue ≥2 months before pregnancy due to fetal risk.

Fingolimod

Multiple-sclerosis agent stopped ≥2 months pre-pregnancy; associated with fetal malformations.

Ribavirin

Antiviral teratogen retained up to 6 months; contraception required for men & women during and 6 mo after therapy.

Leflunomide

DMARD for rheumatoid arthritis; teratogenic—discontinue ≥2 years or perform cholestyramine washout.

Mycophenolate

Immunosuppressant causing major birth defects; stop 6 weeks (♀) or 12 weeks (♂) before conception.

Ciprofloxacin

Fluoroquinolone contraindicated in pregnancy (cartilage damage).

ACE inhibitors

Antihypertensives causing fetal renal failure & skull defects; contraindicated in all trimesters.

Warfarin

Anticoagulant causing fetal hemorrhage & bone defects; replace with LMWH during pregnancy.

Finasteride

5-α-reductase inhibitor that feminizes male fetuses; absolutely contraindicated in pregnancy.

Tamoxifen

Selective estrogen receptor modulator used to treat or prevent ER-positive breast cancer; teratogenic.

Raloxifene

SERM for osteoporosis & breast-cancer prophylaxis; contraindicated in pregnancy.

Nitrofurantoin

First-line oral antibiotic for uncomplicated UTI in pregnancy (avoid at term in G6PD deficiency).

Cefuroxime

Second-generation cephalosporin safe in pregnancy; used for UTI in G6PD patients.

Trimethoprim–sulfamethoxazole (TMP/SMX)

Agent for UTI prophylaxis; avoid in 1st trimester (folate antagonism) and near term (kernicterus).

Benzathine penicillin G

Drug of choice for syphilis in pregnancy; desensitize if penicillin-allergic.

Zidovudine (AZT)

NRTI given during pregnancy & labor to reduce vertical HIV transmission.

Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

Antivirals that mimic nucleosides and terminate HIV DNA chains after incorporation.

Clotrimazole

Topical imidazole safe for treating vulvovaginal candidiasis in pregnancy.

Amphotericin B

Polyene antifungal considered safe in pregnancy; systemic agent of choice for severe mycoses.

Ketoconazole

Azole antifungal contraindicated in pregnancy (embryotoxic and androgen synthesis inhibition).

Valproic acid

Anticonvulsant linked to neural tube defects; avoid in pregnancy if possible.

Levetiracetam

Preferred broad-spectrum antiepileptic in pregnancy & breastfeeding due to favorable safety profile.

Olanzapine

Second-generation antipsychotic acceptable for schizophrenia management during pregnancy.

Methyldopa

Central α-agonist antihypertensive with long safety record in pregnancy.

Labetalol

Mixed α/β-blocker first-line for gestational hypertension and pre-eclampsia.

Propylthiouracil (PTU)

Antithyroid drug used in 1st trimester to treat hyperthyroidism; switch to methimazole thereafter.

Low-molecular-weight heparin (LMWH)

Anticoagulant of choice for VTE in pregnancy; does not cross placenta.

Colostrum

First postpartum milk rich in IgA and nutrients for neonatal immunity.

Metoclopramide

Dopamine-antagonist antiemetic that increases prolactin and can stimulate lactation.

Bromocriptine

Dopamine agonist that suppresses prolactin and can treat hyperprolactinemia or stop lactation.

Cabergoline

Long-acting dopamine agonist used to lower prolactin levels and inhibit lactation.

IgG

Only immunoglobulin class crossing the placenta to provide passive fetal immunity.

IgM

Largest immunoglobulin; first antibody produced in an acute infection but does not cross placenta.

IgE

Immunoglobulin mediating anaphylaxis, asthma, and allergic hypersensitivity reactions.