Exam 2: Special Pop. & Antibiotics Flashcards
(47 cards)
1
Q
What are the age groups associated with different pediatric titles?
A
- Preterm/premature: <36wk gestational age
- Neonate: <30d
- Infant: 1mo-1yr
- Child: 1-12yr
- Adolescent 12-18yr
not little or small adults, less data from trials b/c ethics
2
Q
What affects pharmacokinetic in all Pediatrics?
A
- Developing tissues and organs
- Changing pt body proportions, composition, maturation, & development
- Body Surface Area: > in peds
- Short/Long-term effect on growth & development
- Underlying congenital, chronic, and current disease effect on drug (& vice versa)
3
Q
What is the difference between growth, development, and maturation?
A
- Growth: quantitative change in size of body/parts
- Development: qualitative change in skills or function
- Maturation: slower, genetically controlled, development independent of environment
(May not need to know)
4
Q
How does pediatric body composition affect pharmacokinetics?
A
- Neonate TBW is high ~75-80%
- @ 3 months decreases ~65%
- decrease compensated by increase body fat
-
2yrs dec body fat, & liver & kidney maximum relative size
(doubles 5 mo., 1yr - weight 3x, BSA & length 2x, changes water/fat/protein)
5
Q
How is PO absorption affected in pediatrics?
A
low lipase & no amylase - affect fat soluble
- gut flora > development in breast fed infant
- Gastric pH: alkaline - inc basic drugs, dec acidic drugs
- preterm & full-term neonates: delayed gastric emptying
- neonates & infants: irregular peristalsis (inc. A)
- Young children: greater size duodenum (inc. A)
6
Q
How is IM absorption affected in pediatrics?
A
-
Neonates: dec muscle mass & activity –> dec blood flow/A
– Infants: > muscle capillaries density –> inc A
7
Q
How is percutaneous absorption affected in pediatrics?
A
Neonates and infant
- Skin: dec thickness, inc hydration, dec fat
- MUCH > A than adults –> toxicity
8
Q
How is rectal absorption affected in pediatrics?
A
- avoids first pass elimination
- A erratic & incomplete in neonates & infants (feces, frequency, lack sphincter control)
(is still used)
9
Q
What affects pharmacokinetics in pregnancy?
A
- Physiologic changes (CV, GI, renal, hormonal)
- Placental-fetal unit: drug cross, amount metabolized
- Fetus distribution & elimination drug by fetus
- Underlying congenital, chronic, or current disease
10
Q
How is absorption affected by pregnancy?
A
- PO: Gastric: inc pH, dec motility, inc emptying (slower)
– inc cardiac output –> intestinal blood flow may cancel out affect: min effect on bioavailability & therapeutic effect - Percutaneous: inc by vasodilation, blood flow & water content
- Musocal
11
Q
How is pulmonary absorption affected by pregnancy and being an infant or child?
A
- Pregnancy: inc cardiac & tidal vol (50%) inc blood flow & transfer consider dose reductions
- Infant & children: lower tidal vol & inc RR consider dose inc
12
Q
How does pregnancy affect drug distribution?
A
- inc blood vol & inc total body water, body fat Vd: dilutional effect, arterial pH
- Dec: albumin concentration
13
Q
What affects drug distribution in pediatrics?
A
preterm & neonates
- vascular perfusion: respiratory distress syndrome blood from lungs to tissues & organs
- body composition inc TBW, inc Vd of hydrophilic
- tissue-binding characteristics: inc free drug
- physiochemical properties: lipophilic percu drug A
- plasma protein binding: lower a-1 acid glycoprotein –> inc Vd & concentration free drug
- Route of administration; first pass/IV
14
Q
What is important about metabolism in pediatrics and pregnancy?
A
- Ped: Ultra-metabolizers die from morphine/opioid metabolites
- Pregnancy: some enzymes induced others inhibited, (200-300% inc lower concentration lamotrigine, antiepileptic)
15
Q
How is excretion affected in pediatrics and pregnancy?
A
- Ped: inc first 2 wks, adult rate 1yr, exceeds 2yrs, immature renal system & dec CO –> dec renal blood flow –> dec renal elimination –> inc drug half-life
– usually directly proportional to age - Preg: inc GFR b/c inc CO dec albumin –> inc renal elimination (Lithium clearance doubled)
16
Q
What increases a drug’s ability to cross the placenta?
A
- Lipid soluble drugs
- Nonionized drugs: heparin ionized so can be used in preg
- Unbound (“free”) drugs
- Lower molecular weight (small)
- P-glycoprotein inhibitors “gandalf”
17
Q
What is the placental fetal physiology?
A
- Metabolism: liver enzymes present from 7-8wks but immature
-
Fetal physiology: gestational age at time of drug exposure (ACEI & aspirin more dangerous later)
– First 14d post conception embryo protected (totipotency SC) after 14 susceptible (first 3 mo most important)
– olderL TBW dec, fat inc –> inc lipophilic effect - Teratogenicity of drugs: cause fetal dysgenesis. Factors: gestational age @ exposure, agent/medication, length exposure
- Weigh risk vs benefit
18
Q
How is pregnancy risk noted for drugs?
A
- No longer used: A, B, C, D, X (after 2018)
- Now more information needed (after 2001)
– not apply to approved before 2001 or OTC meds - Pregnancy: risk summary, clinical considerations, & data, pregnancy exposure registry
- Lactation: risk summary, clinical considerations, data: in breast milk & potential effect on infant
- Reproductive: info for pregnancy testing, contraceptive recommendations, infertility info
19
Q
What do we want to know with drugs and lactation?
A
- Does this drug get into the breast milk
- How does it affect the baby
1) Absorption into maternal circulation: [plasma] most enter breastmilk passive diffusion
2) Blood flow to the breast: inc blood flow inc drug in milk
3) Plasma pH (7.45) & milk pH (7.08) favor higher pH
4) Mammary tissue composition higher fat in breast tissue, high lipophilic drug in breast milk
5) Breast milk composition: high affinity protein, fat, water, vitamin, > likely in breastmilk
6) Drug properties more likely in breast milk if low weight, ionization, protein binding, high lipophilicity
7) Drug-protein binding in plasma higher then lower in breast milk
8) Rate of breast milk production: greater –> more diluted
20
Q
What types of drug are preferred or avoided in lactation?
A
Prefer
- Shorter half-lives
- lowest effective dose
- least serious AE
Avoid
- Sustained release (SR)
- High oral bioavailability
Other suggestions
- take dose immediately after breast feeding
- pump and discard milk for short-term illness where risk of drug is thought to outweigh benefits of breastfeeding
21
Q
How should drugs be selected in pediatrics?
A
- Risks & benefits
- Long-term effects
- Dosage formulation
- Obesity
– use weight-based dose, UNLESS exceeds recommended adult dose
22
Q
What are the aspects of weight-based dosing?
A
- Body-weight dosing: most common (mg/kg/d or mg/kg/dose)
- Body-Surface Area (BSA): reserved for antineoplastic (chemo) agents or critically ill
Conversion factor: 1kg/2.2lb
23
Q
What are the routes of administration for pediatrics?
A
- Oral: liquid preferred oral syringe (in cheek & gum) or calibrated cup
(crush & mix sometimes ok, never mix drug w/ baby bottle - drug-nutrient interactions & incomplete dosing) - Rectal
- Parental:
- Inhaled (Pulm):
– pMDI: all children need tube spacer
– Valved holding chamber (VHC) + face mask for pt <4yrs old
24
Q
How do you prevent pediatric medication errors?
A
- Up-to-date allergy profile
- Weight
- State specific dosage strengths for formulation
- Do not abbreviate drug names or pt instructions
- Avoid abbreviations for dosage units
- Zero before decimal
- Avoid zero after decimal
- Standardize concentrations of high-alert medications
- Use oral syringes for liquids
- Create drug order pathways for protocols
- Collaborate & educate all healthcare members
- Automated dispensing cabinets, smart infusion pumps, bar coding
25
Why are older adults pharmacologically challenging?
- Physiology
- Multiple comorbid conditions
- Adherence: cognitive & social issues
- Lack of testing
- Fastest growing age group
(review)
26
How is absorption affected in older adults?
- Oropharyngeal muscle dysmotility & altered swallowing
- Dec esophageal peristalsis & lower esophageal sphincter pressure
- Dec gastric motility, secretion emptying
- Dec Propulsive motility of colon
- Impair mucous-bicarbonate barrier
(review)
- **dec blood flow**
- **inc gastric pH**
- **dec gastric emptying**
27
How is distribution affected in older adults?
- **Dec lean muscle mass**, **inc fat stores**
- **dec** body water content
- **dec** serum **albumin**
- Inc Vd of lipophilic can --> **inc half-lives** (Diazepam in young adults 20 hrs, elders 70hrs+)
28
How is metabolism affected in older adults?
- **Dec hepatic size & blood flow**
- Dec phase one --> dec total body clearance (**dec enzymatic activity**)
- Phase II **not** affected
29
How is excretion affected in older adults?
- Dec renal blood flow (GFR dec 1%/yr after 40, & accelerates advanced age)
- **dec secretion**
- dec lean body mass--> dec creatinine formation + **dec GFR** can make serum creatinine appear normal
- **Normal SCr x= normal GFR**
- Use Crockcroft-Gault or MDRD
30
What are the pharmacodynamic changes in the older adult?
- Inc CNS effects of drugs
- Inc sedative effects of agents
- Changes in CV system: orthostatic hypotension b/c loss baroreceptor reflex & change in cerebral blood flow
31
What causes polypharmacy in the older adult?
- Varied symptoms & complaints associated w/ multiple chronic illnesses
- Pressure to "prescribe something"
- Prescribing cascade: add when unsuccessful
- Pt stockpiling meds b/c cost
- Pts sharing meds
- Poly-providers: multiple specialists, need PCP
- Self-prescribe OTC
32
What is important about adverse drug reactions in older adults?
- Any symptom in elderly considered side effect until proven otherwise
- Preventable AE: falls, fractures, delirium
- Older women > risk b/c receive more Rx & > muscle loss
33
What are common drug-disease interactions in Older adults? (FYI)
**Anticholinergics**, **TCA**, nonaspirin NSAIDs, first-gen calcium channel blockers, opioid analgesics, barbiturates, benzodiazepines, corticosteroids, antipsychotics, sedative hypnotics, digoxin, metoclopramide, aspirin, thioridazine, bupropion, alpha-blockers
34
What lifestyle factors may influence adverse drug reactions?
- **alcohol** & recreational drugs
- **Caffeine & nicotine use**
35
What are adherence issues in older adults?
- 40% don't take properly, & take more than 5med/wk
- **Cost factors**
- **Side effects**
- **Physical & mental changes** (vision, arthritis)
- **Self-medicating** (& X telling PCP)
36
What are special considerations for long-term care for older adults?
- 50% residence fall annually
- Required to receive monthly drug regimen review
- **Antipsychotics:** over dx as chem restraint (include muscle reactants, anticholinergics, antihistamines, OTC natural & herbals)
-- 14-day limits when PRN
- **Anxiolytics**: nonpharmacologic preferred (SSRI > benzos)
- **antidepressants**: SSRI > TCAs but drug interactions & SE
- **Severe or persistent pain**: tolerance decreases w/ age
- **Urinary incontinence, UTIs**: AMS
- **Respiratory infections**: spread quickly through facilities
- **Constipation**: nonpharmacologic (activity, prune juice, fiber) over meds
37
How can providers reduce psychotic medication use?
- Prevent inappropriate initiation
- Taper & discontinue inappropriate
- Endure appropriate use/monitoring/documentation
- Improve disruptive behaviors w/o psychotropic meds
- Encourage more structured & broader approach to manage behaviors
(Review)
38
What are nonpharmacologic antianxity treatments?
- Est daily routines in structured environment
- Consistent caregiving & hygiene assistance
- Avoid overstimulation
- Limit social visits
- Schedule quiet time w/ rests/naps
(Review)
39
What are primary guidelines for safely prescribing to older adults?
- **Beer's criteria: consensus-based document listing potentially inappropriate medications for use in older adults and guidelines for safe prescribing practices**
- Choose wisely: "Five things to question"
1) Dementia & Behavioral & Psychological Symptoms of Dementia
2) Screeding & Medication Management
3) Antibiotic use
4) Diabetes management
5) Nutritional management
40
Why should you question Dementia & Behavioral & Psychological Symptoms of Dementia?
- **Avoid** Rx **cholinesterase inhibitors** w/o periodic assessment for cognitive & GI effects: 12 wk trial
- Assess use of chemical & physical restraints
-- **antipsychotics** limited benefit & serious harm: **limit to pt w/ imminent threat to themselves or others**
- Avoid as first choice for BPSD assess underlying cause
- Avoid benzos/sedatives as first choice for insomnia, agitation, or delirium
-- reserve for alcohol withdrawal/delirium tremens (DTs) or severe generalized anxiety disorder (GAD)
- Avoid physical restraints for hospitalized older adults when delirium is identified
**proper & thoughtful use**
41
Why should screening and medication management be questioned?
- Consider benefit of screening - what do with information esp when life expectancy is <10 yrs
- Hypercholesterolemia no longer major risk factor at older ages
- Monthly review LTC residents for unnecessary and underuse of meds
**some not beneficial b/c limited effectiveness and/or dangerous AE**
42
Why should antibiotic use be questioned?
- **Do not use antimicrobials for asymptomatic bacteriuria in older adults**
- May --> erroneous assumption UTI cause AMS --> fail detect problem
- Leads to antibiotic overuse which can cause other problems
**X request UA or Rx antibiotics w/o clear indication**
43
What should diabetes management be questioned?
- Basal/bolus insulin therapy over sliding scale insulin (SSI), unless short-term in hospital, because more closely mimics normal physiology
- Set reasonable AIc goals, it takes time to have microvascular benefits from tight glycemic control
-- **7-7.5%** healthy >65 yo w/ long life expectancy
-- **7.5-8%** with moderate comorbidity & lief expectancy <10yrs
-- **8-9%** w/ multiple comorbidities & shorter life expectancy
44
Why should nutritional management be questioned?
- **Percutaneous feeding tubes** X prolong/improve QOL in pt w/ advanced dementia
-- (fluid overload, diarrhea, abdominal pain. local complications, less human interaction, inc risk aspiration)
-- avoid appetite stimulants & high-calorie supplements to treat anorexia/cachexia
-- preferred: oral-assisted feedings
45
What are secondary guidelines for safe prescribing to older adults?
- **Explore alternatives to medications**
- **Simplify the regimen**: 2 conditions tog, lowest dose
- **Edu adults & caregivers**: fear after reading package inserts
- **Review medications**: bring & review @ every appointment, esp + specialists & ER
46
What are the methods of therapeutic monitoring?
- Pill boxes: check & count
- Open-ended questions: how many days/week do you miss taking meds
- Routinely schedule and monitor labs when patients are on meds with narrow therapeutic index
- Diuretics & ACEI: periodic renal profile for electrolyte imbalances, renal insufficiency, and/or renal artery stenosis
47
What are the medications with narrow therapeutic ranges?
- Warfarin
- Theophyllin
- Lithum
- Phenetoyn
- Gentamycin
- Digoxin
- Carbamazepine
- Valproic acid
