special populations ppt Flashcards
what happens to plasma volume in preg?
increases (30-50%)
what happens to plasma albumin concentration in pregnancy? why?
decreases. The rate of albumin production is increased. However, serum levels fall because of plasma volume expansion. Also, many plasma-protein binding sites are occupied by hormones and other endogenous substances that increase during pregnancy.
what does the effect of change in albumin levels in pregnant woman have on binding capacity for drugs?
The decreased capacity for drug binding leaves more free or unbound drug available for therapeutic or adverse effects on the mother and for placental transfer to the fetus. Thus, a given dose of a drug is likely to produce greater effects than it would in the nonpregnant state
inc or dec CO in preg?
increase
inc or dec in renal blood flow and GFR in preg?
inc
inc or dec in hepatic metb in preg?
inc
inc or dec of progesterone levels in preg?
inc
placental transfer may occur by what?
Passive diffusion
Facilitated diffusion
Active transport
as the placenta gets bigger does the rate of drug transfer inc or dec?
inc bc more blood. Maternal viral, bacterial / protozoa infections can reach to fetus by crossing placental barrier .
what was thalidomide used for? how many people did it affect?
MORNING SICKNESS, insomnia, coughs, colds, headaches,
10,000 children born worldwide. stopped in 1964. caused rate limbo and ear defects
what are some factors of teratogens?
timing of exposure, developmental stage during exposure, maternal dose and duration, maternal pharmacokinetics, genetic phactors/phenotypes, interactions between agents
what is the threshold effect in re: exposure or teratogens?
the phenomenon in which a particular teratogen is relatively harmless in small doses but becomes harmful when exposure reaches a certain level (the threshold)
what is genetic variability in re: teratogens?
another factor that determines whether a specific teratogen will be harmful is the genetic make-up of the developing organism.
possessing and not possessing certain genes may make the developing child more susceptible to the effect of a teratogen
what is the interaction effect in re: teratogens?
the phenomenon in which a particular teratogen’s potential for causing harm increases when it is combined with another teratogen or another risk factor
examples of teratogens?
rubella, fetal-aclohol syndrome, env’tal toxins, drugs
what is rubella?
-a viral disease, if contracted early during pregnancy, can harm the fetus
à causes blindness, deafness, and damage to the central nervous system
what do psychoactive drugs do? (marijuana, alcohol, tobacco)
slow down fetal growth and inc chances of premature labour
what does fetal alcohol syndrome do to the fetus?
a cluster of birth defects, including abnormal facial characteristics, slow physical growth, and retarded mental development
à these birth defects are caused by the mother’s drinking excessive quantities of alcohol when pregnant
what does category A mean?
controlled studies of pregnant women show no risk in first trimester
what does category B mean?
animal studies show no risk, unconfirmed in humans
what does category c mean
animal studies show risk, caution advised. benefits may outweigh risks
what does category d mean
evidence of risk to human fetus, benefits may outright risks in serious conditions
what does category x mean
risk outweighs benefits, contraindicated in preg
what category is acetaminophen?
cat b
what category is aspirin
c
what category are ACE inhiitors
D
what does folic acid do?
drug given to prevent neural tube birth defect in preg
are herbal supplements ok to take during preg?
no
is ginger safe to take in preg?
Ginger has been used to relieve nausea and vomiting during pregnancy and is probably safe
how do u know if u have pre induced htn? tx?
140/90 twice in 4 hours.
anticonvulsant, nifedipine
why are NSAIDs not safe in preg? when are they especially unsafe?
k when used especially after 30 weeks
Premature closure of ductus arteriosis
Pulmonary hypertension in infant
Possible # in miscarriage
what happens if you take dilantin preg?
fetal hydration syndrome (craniofacial abnormalities, intrauterine growth retardation, mental retardation)
what do you used misoprostol for? why is this unsafe during preg?
used to treat gastric ulcers but is a prostaglandin analog used to induce abortions
what is valproic acid? why is it dangerous in preg?
anticonvulsant and used for bipolar disorder. it causes neural tube defects
what is carbamazepine? why is it dangerous during preg?
for epilepsy. causes cranial facial defects and spina bifida
are SSRis ok during preg? which ones? which is NOT
generally ok during preg like citalopram, prozac and zoloft but paroxetine is not safe. causes heart and lung defects
what is isotretinoin? is it safe during preg? what does it cause if its unsafe
accurate. several fetal abnoramltiiese
what abx are contraindicated during preg and what do they cause
MCAT
M-metronidazole (flagyl) causing hepatic failure
C-chloramphernicol (chlormycetin) -gray babe syndrome
A- aminoglycosides (streptomycin, neomycin, gentamicin)-causes ototoxicity
T- tetracyclines (teeth discolouration and liver failure)
what abx are considered safe?
amoxiciliiin, ampicillin, clindaycin, Erythromycin
Penicillin
what does alcohol cause in preg?
– risk of low birth weight, effects of nicotine and carbon monoxide -> $ O2 to fetus, also risk of heart defects, learning disabilities, behaviour problems, $ IQ
what does marijuana cause?
affects growth and development of nervous system, can lead to cognitive or MH disorders, heavy use affects fertility in men and women
what do opiates cause?
risk of low birth weight, SIDS
is it okay if a mom tries to withdrawal from opiates during preg/
no can cause miscarriage. methadone maintenance recommended
what are tocolytics? ex of a drug that may be used as a tocolytic?
drugs that inhibit labor and maintain preg
nifedine
what are some nonpharmacologic treatments to inhibit labor?
bedrest, hydration dn sedation
what are some beta-adrenergics that relax uterine smooth muscle?
Ritodrine (high risk of premature birth or fetal death) and terbutaline (beta b receptor - bronchodilator)
what would you give to initiate labour?
oxytocin
what might you give to manage Post party hemorrhage?
methlergonovine (vasoconstriction) or oxytocin
what do you give to baby on deliver?
Vitamin K required for liver synthesis of clotting factors. One dose of phytonadione 0.5 to 1 mg IM at delivery
Ophthalmia neonatorum is bacterial form of conjunctivitis caused most commonly by Chlamydia trachomatis. Erythromycin 0.5% applied OU at delivery. Effective against gonococcal infections, as well.
should a mom with HIV breastfeed?
no it is transmitted in milk
can you take anticonvulsants while breastfeeding?
yes but monitor infant for side effects
what occurs if baby is given chloramphenicol?
Immature glucuronosyl transferase activity in the liver is also one of the reasons the grey baby syndrome. inadequate renal excretion is another reason.
when does a babies weight double? triple?
5 months and triples by 1 year.
when does a babies body surface area double?
1 year
slide 25, 26 on liver enzymes
.
is absorption delayed or faster in infants? why?
delayed bc prolonged gastric emptying and diminished pancreatic enzyme function
during distribution is protein binding capacity inc or dec in infants?
decreased which causes risk of toxicity. less albumin
when is an infants protein binding capacity the same as adults
1 year
why is distribution different in babies?
increasedHigher percentage of body weight in water
Blood-brain barrier not fully developed -> less protection
because infants have a higher percentage of body weight in water do water soluble drugs need to be inc or dec in dosing?
increased
is metb inc or dec in children? why
dec bc liver not fully mature until 1 year
is excretion inc or dec in infants?
dec bc renal function reduced unti 1 year
children of 1-2 years - 12 years are similar to infants for ADME except? what does this do to drug dosing?
metabolize faster (until puberty)
inc or more freq drug dosiing
how is dosage determined for children?
mg/kg!
recommendations to improve compliance for children?
Calibrated medicine spoon
Ask if parent gives another dose after spitting out
Stress importance of duration of treatment
Instruct whether to wake the child during q6h dosing
Give some responsibility to the child for his/her care
who is the largest consumers of Rx meds?
geriatrics
what is the average amount of drugs/senior?
3-4
what is the general reason ADME differs in older adults?
organ decline
what are some concerns with geriatric pharm?
changes in body metabolism
drug interactions
disease processes
changes in lifestyle
Co decreases __% a year after 25-30 years of age
1
what changes to GI tract affect absorption?
what effect does this have?
decreased blood flow
reduced absorptive surface area
decreased gastric secretions
decreased motility
SLOWED rate of drug absorption
SLOWED rate of drug action
will all of the drug be absorbed in older adults?
same amount of drug absorption but over a longer period of time
does the peak drug level stay the same in the older adult?
no its slower absorption so peak drug level decreases with age
what happens to body mass, water and fat in older adult- hwhat does this affect?
Lean body mass (muscle) % decreases
Body water % decreases
Body fat increases
what effect does lipid soluble drugs have on older drugs?w hy?
wider distribution bc more body fat
where do lipid soluble drugs go in older adults?
adipose tissue and muscle and organs with greater fat
if organs with lower fat content get less lipid soluble drugs what does this do to the elimination and half life, duration, etc?
bc the liver and kidney have less fat then the elimination is slowed down, greater half life and greater duration of action. stuck in the body longer essentially.
does the concentration of drug change in older adults?
higher bc more drug and less fluid bc body water changes
does the concentration of water-soluble drugs change?
less bodily fluid to dissolve in so less distribution to organs with high adipose content so greater concentration of drugs in certain organs
