Test 1 Fall 2024 Flashcards
Biotransformation Process
metabolic process that changes the chemical structure of substances that enter the body. Chemical changes a substance undergoes in the body.
Therapeutic Index
- Ratio of lethal doses in 50% of the population over the median minimum effective dose in 50% of the population the higher the therapeutic index the safer the drug
Drug Efficacy
Capacity to induce a therapeutic response. As opposed to effectiveness, which is the ability of a drug to produce a therapeutic response in real-life conditions.
What anticoagulants are contraindicated and which ones are safe?
- SAFE—> Heparin and Lovenox because they do not cross the placenta. There is increased renal excretion and protein binding in pregnancy.
- NOT SAFE–Warfarin is not safe due to harmful fetal effects. Avoid oral direct thrombin inhibitors and factor Xa inhibitors.
Transdermal Drug Absorption
- Drugs are applied to the skin for absorption; there is a consistent drug dose over time.
- many types ( patches, lotions, Gels, Sprays).
- If the skin is abraded or burned, absorption is more rapid
- inflamed skin allows the drug molecules to pass through the skin easily because of an increase in cutaneous blood flow
- If a patient has lotions or ointments, they can impair drug transfer.
Key Drug Principles During Pregnancy
1) Accurate diagnosis of condition
2) Lowest effective dose of drug for shortest period of time
3) Use single action, short acting medications rather than long acting or combination drugs
4) If more than one option, use the one that has been used the longest and has the most data supporting its safety
5) Avoid drugs during first trimester if possible
6) Choose topical or nasal instead of oral when possible
7) Use medications when benefit outweighs the risk
8) Do not discontinue medication for preexisting condition unless there is high suspicion or known risk of maternal or fetal harm (i.e. antiepileptic drugs)
9) You must consider potential pregnancy before prescribing to woman of childbearing age
10) Women on long term drug therapy need to be counseled before pregnancy
11) Drugs may have altered effects in pregnancy
Seizure disorders in pregnancy and what meds are safe
- Pharmacokinetic changes in pregnancy affect antiepileptic drug (AED) metabolism. Major risk factors are fetal malformations and convulsions.
- AED monotherapy is preferred due to decreased fetal effect. The fewest necessary anticonvulsants are given in the lowest dose for seizure control.
- SAFE–Lamotrigine (Lamictal), Levetiracetam (Keppra), and Oxcarbazepine (Trileptal).
- AVOID–Valproate (Depakote), and Topiramate (Topamax)
Antibiotics in Pregnancy-ototoxicity
- Aminoglycoside (streptomycin and kanamycins) may cause irreversible bilateral congenital deafness in children (ototoxicity) whose mothers were treated during first trimester
- Include: Amikacin, Gentamycin, Kanamycin, Neomycin, Netilmicin, streptomycin and tobramycin
What hypertensives are safe, which ones are absolutely contraindicated?
- ACE inhibitors, and ARBs should not be taken during pregnancy due to known fetotoxic effects
- Safe and most frequently prescribed for pregnant women include methyldopa (Aldomet), labetalol (Trandate), and nifedipine (Procardia)
Pharmacokinetics in Pregnancy
Reduction in plasma protein esp. Albumin may increase the plasma levels of free drug, Albumin if a major protein that BINDS to drugs like ASA, anticonvulsants and NSAIDS. So then increases free drug fractions as serum albumin falls but since drug is not bound the drug may be cleared faster , metabolism
Hepatic first-pass
medication is administered orally and then goes to GI tract through the portal system to the liver and then into circulation. Metabolism is the process of changing one chemical into another. Metabolism of medications can occur in every body tissue but occurs mostly in smooth muscle of the liver, the liver is a major organ in drug metabolism
* First pass effect causes a reduction in bioavailability and therapeutic action
Half-life and Pregnancy
- amount of time it takes for plasma concentrations to be reduced by 50%
- Serum levels and half-life of many antibiotics are reduced bc of rapid excretion with increased GFR
- Preg women require higher doses of antibiotics for infections
- Anteleptic drugs plasma clearance decreases and causes increased risk of seizures, drug levels need to be monitored regularly to ensure therapeutic dose
NSAIDs and Pregnancy
- Disrupt prostaglandin cascade which initiates labor; linked to preterm pregnancy and premature closure of ductus arteriosus, bleeding and bilirubin issues; avoid after 32 weeks gestation. It can inhibit the fetal COX (cyclooxygenase)which is an enzyme protein that produces prostaglandins
What drugs monitor the serum plasma levels?
Live viruses vs. non-live viruses (safety, indications)
- Live viral vaccines are contraindicated due to risk of infection and potential harm to fetus (rubella, varicella) inactivated vaccines are safe (Hep And B, polio, influenza and rabies) TDAP is given between 27 and 36 weeks of pregnancy
Effects of ACE inhibitors and Pregnancy
- Contraindicated for use during pregnancy
- Can cause fetal renal abnormalities and cardiac anomalies
Accutane and Pregnancy
- Pregnancy Category X
Valproic Acid and Pregnancy
1% risk of neural tube defect, cardiovascular defects, developmental delays, intrauterine growth restriction, reduced intelligence associated with use of valproic acid or valproate
Most critical time for teratogenic exposure
Non-stress tests
- Method to assess fetal well-being by observing the FHR response to fetal movement
- External electronic fetal monitoring (EFM) is used to record FHR accelerations in response to fetal movement
- Indications: decreased fetal movement, post-term, diabetes, hypertension, IUGR
