Pregnancy Flashcards
Physiological changes during pregnancy
Reduced GI motility, inc pH, dec serum albumin binding capacity, variability in hepatic metabolism, inc renal drug clearance, inc total body water (8L), placental drug transfer
Drug selection criteria during pregnancy
pregnancy category, timing of drug, lowest effective dose, does drug have inc protein binding
Category A classification
adequate and well controlled studies fail to show risk to fetus in 1st trimester or later
Category B classification
animal studies have failed to show risk, but no adequate studies in humans
Category C classification
Animal studies show adverse effects in fetus, no studies in humans, potential benefit may warrent use of drug
Category D classification
positive evidence in human fetus, but benefits may warrant use despite, no other drug option
Category X classification
studies in animal and humans have shown fetal abnormalities, the risks of using the drug outweighs the benefit, there are other alternatives
Antibiotics category B
penicillins, cephalosporins, macrolides, aztreonam, clindamycin, daptomycin, fosfomycin, carbapenems, metronidazole, nitrofurantoin, vancomycin (PO)
Antibiotics category C
fluoroquinolones (cartilage damage, last line only), linezolid, clarithromycin, sulfa/trimethoprim (Bactrim)- avoid during first trimester and after 32 weeks, vancomycin (IV)
Bactrim risks
risk of kernicterus, neural tube defects, may use for prophylaxis of PCP, or toxoplasmic gondii encephalitis
Vancomycin (IV)
no adverse effects reported, usually for prophylaxis of strep B
Antidepressants in pregnancy
TCA- Cat C, Nortriptyline preferred, taper 10-14 days before expect DOD, SSRIs- cat C (paroxetine cat D), no effects in late 3rd, taper 10-14 days, SNRIs- cat C, mirtazapine, trazodone- cat C, DRI- Cat B
Antibiotics Category D
Aminoglycosides (CN 8 toxicity), Tigecycline (tooth discoloration), tetracyclines (tooth discoloration)
Other Category D drugs
aspirin, lithium, paroxetine, ACE-I, ARBs, anticonvulsants
Category X drugs
Statins, warfarin, thalidomide, methotrexate, isotretinoin (Accutane), ergotamines
OTC pregnancy drugs to avoid
aspirin, NSAIDs, pepto-bismol, kaopectate, sodium bicarbonate, lomotil
Vaginal azole antifungals
clotrimazole, terconazole-DOC, use 7 days, avoid during 1st trimester
OTC category A
dextromethorphan, doxylamine
OTC category B
APAP, chlopheniramine, cetirizine, loratadine, diphenhydramine
OTC category C
oxymetazoline
Things to consider during lactation
consequences of infant exposure, amt of infant drug exposure, necessity of therapy, alternating forms of nutrition
Assessment of wt
low birth wt= 2500 g, very low
Challenges to neonatal therapy
the unknown, volumes, safety (details!)
Pediatric PK/PD absorption
higher gastric pH compromises bioavailability of acid stable drugs, irregular gastric emptying times, absorption in skin is much higher
Pediatric PK/PD metabolism
compromised hepatic metabolism, dec blood flow and enzyme activity
Pediatric PK/PD distribution
better distribution because of inc body water/dec fat, inc BBB penetration, altered perfusion, altered plasma protein binding
Pediatric PK/PD elimination
renal blood flow dec in utero, GFR improves slowly before 32 weeks, then rapidly, tubular secretion matures at 6 mo, assess fx w/ urine output
Goal urine output for assessing renal fx
> 1 ml/kg/hr
SCr in neonates
caution w/SCr, baby has mom’s SCr up to 7 days
Dosing in pediatrics
use mg/kg, never give more than adult dose, dose varies w/age, disease states, organ fx
