Flashcards in Factors Modifying Drug Activity Deck (22):
What are the factors in modifying drug activity?
Effect of disease
What are some factors that specifically effect the elderly?
May absorb drugs less completely or more slowly because of dec splanchnic blood flow or delayed gastric emptying
Reduced gastic acidity
Reduction in muscle mass
Qualitative changes in drug-binding sites
Reduced renal blood flow
Dec cardiac output
Which drug responses change with aging?
Changes in receptors
Changes in postreceptor signaling mechanism
Changes in homeostatic control
What are some impaired homeostatic mechanism in the elderly?
Dec activity of arotic/carotid chemoreceptors
Reduced baroreceptor reflex
Inappropriate response to blood glucose and insulin
Altered neurological control of bowel and bladder
What are some drug dispositions in peds?
Term infants in 1 mo of life
1 mo to 2 yrs
2 ys to 12yrs
12 yrs to 18 yrs
What are limited in preterms that have drug issues?
Gfr's 1/10 of newborn
Limitation on tubular reabsoption
Glucuronidation pathway limited
Gastric acids not found or limited
Metabolism and elimination not active
Skin not totally protective
Dec plasma albumin and total plasma protein conc
Dec drug binding ability
Issue with drugs for term infants to 1 mo
Inc body water, dec body fat
Dec exocrine pancreatic function
Dec albumin conc and binding
CYP450 slow functioning
Phase 1 oxidation rxn reduced
High sulfate conjugation
Issues with drugs for 1 mo to 2 yrs
Rapid growth, things work pretty well
Issues with drugs for 2 yrs to 12 yrs
Drug clearance inc and exceeds adult levels
Shorter half-lives and dosing requirements are frequently greater
Issues with drugs for 12 yrs t 18 yrs
Dec drug absorption and elimination in female
Females less gastric acidity and inc gastric emptying
Estrogen dec CYP450 - dec phase I pathway
What should be done for children with chronic illness for drugs?
Possible inc of drug dosages like is CF who have inc hepatic metabolism (inc drug clearance)
Are most drugs given the peds used for the same things as adults?
What is example of a drug used for adults that is different for children?
Caffeine - used to treat apnea
What does tetracycline do in children it doesn't do in adults?
What are the factors used to calculate pediatric dose?
Age, weight, surface area
Should never exceed adult dose
What is the standard for therapeutic dose in humans?
70 kg adult
How does sex influence drug administration?
No real significant differences
Abnormal biotransformation or reaction to a drug due to a genetic difference (not defect)
Concomitant of drug therapy
Effect of one drug may be altered significantly by the administration of another drug
Can enhance or reduce therapeutic effects or toxicity
What is most likely the effects of time administration?
Inc enzyme activity during the day probably
What are some reason the pt does not comply?
Reminded of disease
Does not feel sick
Adverse drug reactions (ADRs)