Drugs in preganancy Flashcards
UTI treatment in pregnant women
- First line
- Second line
First
- Nitrofurantoin
- BD, 7 days
Second
- Amoxicillin
- Cefalexin
Vitamin A derivatives
Teratongenic
- First 3 weeks of gestation
Effects
- CNS, cardiac and craniofacial abnormalities
Examples
- Roaccutane (Isotretinoin)
Hypertension management in pregnancy
- BP target
Antihypertensives that increase risk of congenital abnormalities
- ACEi
- ARBs
- Thiazide/ thiazie-like diuretics
BP aim= 135/85
Alternatives
- Labetalol
- Nifedipine (secondary to labetalol)
- third line= methyldopa
Valproate and pregnancy
Teratogenic
- Most be stopped even before conception
Alternatives for epilepsy management
- Levetiracetam
Offer 5mg folic acid if considering conception
Contraception
- Possible side effects with AEDs
Teratongenic drugs in pregnancy
- Examples (9)
Alcohol
Tetracyclines
Warfarin
Antibiotics
Anti-thyroid/ convulsants/ hypertensives
Lithium
Herbal remedies
Effects of pregnancy of drug absorption
- Oral
- Inhaled
- IM
Orally
- Reduced gastric empyting
- Reduced small intestinal motility
Inhaled
- Enhanced effect
IM
- Enhanced effect
Volume of distribution equation
Dose/ Plasma conc
Dependent on lipid solubility/ protein binding
Effects of pregnancy on volume of distribution
Increased Vd due to increased plasma
Reduced maternal album concentrations
- Affects highly bound protein drugs
Effects of pregnancy on metabolism of drugs
Induction of cytochrome P450
- Competitive inhibition of some P450 enzymes
Cholestasis
Pregnancy and lamotrigine
Plasma concentration of lamotrigine/ phenytoin/ carbamazepine drops in pregnancy
- Increases risk of more seizures
Therefore concentration should be monitored.
Effects of pregnancy on drug clearance
Increased renal plasma flow
= increased renal clearance
Tetracycline and pregnancy
Interferes with bone formation
- Can cause perament staining
- Can cause abnormal teeth/ bone formation
Avoid in pregnancy and breastfeeding,
