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44 Cards in this Set
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Q: Elderly male pt presents w/ RA & current medications include methotrexate, meloxicam, & sulfazalazine. His lab results indicate decr renal fxn, w creatinine clearance of 75 & GFR 60 ml/min. Meloxicam (85% bound to plasma proteins) needs to be dose adjusted d/t renal decline. What is the expected clearance? |
A: 9 ml/min Clearance = FF * GFR** (need to know!) FF = 100% - % bound = 100 - 85% = 0.15 Clearance = 0.15 * 60 = 9 (normal clearance should be around 18, normal GFR around 90 (f) - 120 (m)) |
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Elderly pts have less body water --> decreased volume of distribution = higher concentration of ____________ (possible toxicity) |
water soluble drugs (aminoglycosides) (req lower doses) |
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Elderly pts have more body fat --> prolonged action of fat soluble drugs = increased _________ |
increased half-life & redistribution (benzodiazepines & barbiturates) (use shorter half life drugs) |
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Elderly pts have lower serum proteins (albumin) --> increased concentration of FF drug form = increased _________ (possible toxicity) |
increased activity of drugs (Digoxin, Theophyllin, NSAIDs) (req lower dose) |
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Elderly pts have slowed Phase I, cytochrome P450 HEPATIC metabolism, this can increase levels of _________ |
increase levels of drugs metabolized by cyt P450: Fentanyl, methadone Acetaminophen Erythro/ Clarithromycin Itra/ Ketoconazole Amiodarone, lidocaine, quinidine Ca Channel blockers Cisapride Sertraline, nefazadone Alprazolam, zolpidem, triazolam Astemizole, loratadine, terfenadine Cyclosporine Cortisol (sex-hormones) Carbamazepine( (autoinducer) |
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Cyt P50 _________ will futher increase the levels of drugs metabolized by Cyt P450, increasing the likelihood of toxicity in elderly pts |
CytP450 inhibitors : Cimetidine Erythro/ clarithromycin (macrolides) Diltiazem, nicardipine, verapamil Itra/ ketoconozole Fluoxetine, methylphenidate grapefruit juice (esp avoid w statins) |
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Cyt P450__________ will decrease the levels of the drugs (increase Cyt P450 metabolism), possible decreasing the efficacy |
Cyt P450 Inducers: Barbiturates Carbamazepine (auto-inducer) Glucocorticoids Phenytoin St. John's Wort |
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What will happen if you drink grapefruit with a calcium channel blocker (Femlodipine)? |
Grapefruit inhibits Cyt P450---> Increases concentration of Femlodipine (ca channel blocker)--> vasodilation--> BP decrease--> reflex tachycardia |
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Elderly pts also have decreased renal excretion & should not be given _______ |
Drugs that are excreted predominantly renally--> active drug metabolites accumulate--> prolonged effects, possible adverse effects (seizures, etc) |
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Q: Elderly pt w severe GI pain is given meperidine. 45 mins later he develops tachycardia, hypertension, hyperpyrexia, & seizures. He also takes a psych medication. What drug is most likely to cause this interaction? |
A: Imipramine (TCA) TCA's can cause coma, convulsions, & cardiac toxicity (3 C's) Meperidine (opioid) also may cause convulsions, confusion, or serotonin syndrome most likely combination^ |
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Q: An elderly pt is taking vincristine, doxorubicin, & dexamethasone for Multiple myeloma. After 6 wks of therapy, not much improvement is seen (tx failure). Pt is also taking a herbal supplement for depression, what is it? |
A: St. John's Wort *Cyt P450 inducer--> increases the metabolism of other drugs--> decreases efficacy |
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Q: An elderly pt w/ BPH & Hypertension develops a viral URI & takes OTC cold medicine w/ a decongestant & diphenhydramine. His BP is not 190/80 (worsened HTN) & he is unable to urinate (worsened BPH). Why? |
A: diphenhydramine (bendadryl) is BOTH an antihistamine (H1 blocker) & an anticholinergic--> urinary retention decongestants (pseudoephendrine & phenylephrine) are alpha 1 agonists--> Inc BP, urinary retention |
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Anticholinergic meds (ex: diphenhydramine) block ___________________ |
Parasympathetics inhibit detrusor muscle contraction = inhibit bladder emptying |
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Alpha-adrenergic meds (ex: decongetants) increase ______________ activity |
Sympathetic activity urethral sphincter contraction--> urinary retention increase systemic vascular resistance--> inc BP |
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Alpha1-adrenergic antagonists may be used to relieve the urinary retention & help reduce BP. What is the danger in these in the elderly? |
Increases risk of fall d/t orthostatic hypotension *baroreceptor sensitivity decreases w/ age, also worsening postural hypotension--> falls *falls & hip fx assoc w high mortality in elderly pts |
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What other drug groups are anticholinergics? In addition to urinary retention, what are the other neg SEs? |
Anticholinergics: Antihistamines TCAs Antispasmodics Muscle relaxants SEs: Dry mouth urinary retention, constipation Confusion, delirium |
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What other drugs are likely to cause confusion/ delirium in the elderly? why? |
Meperidine- causes confusion, active metabolites are renally excreted, decreased excretion in elderly Diazepam- long acting benzo, incr half-life & sensitivity in elderly, inc risk of falls & fractures |
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Beta-sensitivity (decr response to Betat antagonists) decreases w/ age d.t the decrease in high affinity receptors & possible also d.t _________ |
decrease in G proteins w/ age *Adrenoceptors are G protein coupled (Exception: beta-blockers are used in elderly w/ high BP) |
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What are the Sign/symptoms of Serotonin Syndrome (high serotonin levels)? |
agitation confusion tachycardia HA diaphoresis diarrhea--> hyperthermia & muscular hypertonicity |
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What drug interactions are assoc w/ severe serotonin syndrome? |
Phenelzine MAOI) + meperidine (opioid) Tranylcypromine + Imipramine (TCA) Phenelzine (MAOI) + SSRIs Paroxetine (SSRI) + Buspirone Linezolide (antibiotic) + Citalopram (SSRI) Moclobermide (MAOI) + SSRI Tramadol (opioid), Venlafaxine, + Mirtazapine |
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____________ is a potent CYP 450 (3A4) inducer & P-glycoprotein drug tansporter that SHOULD NEVER be combined w/ any drug that inc serotonin (antidepressant)--> Serotonin Syndrome |
St. John's Wort |
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As a potent inducer, St. John's Wort, increased the metabolism & inhibits the efficacy of what drugs? |
inhibits the effects of; HIV protease inhibitors immunosuppressants antineoplastic agents |
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St. John's Wort also interacts w/ ________ & should NOT be used |
warfarin |
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Aspirin should NOT be combined w what herbal meds? |
Ginkgo, Ginseng, Garlic, Ginger ---> displace warfarin ---> Increase bleeding |
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Ginkgo should also not be combined w ______ & Ginseng not w _________ |
Ginkgo NOT w trazodone Ginseng NOT w amlodipine |
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Valerian should not be used w ________ |
Lorazepam |
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NO herbals should be used w ANY ________ |
Antiepileptics |
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Benzodiazapines should be avoided in elderly d/t inc risk of falls & delirium. Which 2 are safest to use? |
Lorazepam & Oxezepam DO not have active renal metabolites |
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Which drugs should never be given to an elderly pt on L-dopa/carbidop & sellegine? |
MAOIs (phenelezine)--> hypertensive crisis |
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To minimize adverse SEs in elderly pts, ALWAYS __________ |
start LOW & go SLOW |
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What drug should NEVER be given to an elderly hyperlipidemic pt taking simvastatin? |
grapefruit juice CYT P450 inhibitor--> toxicity--> rhabdomylosis |
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___________ is CI in pediatric pts d/t risk of developing tendonitis |
Flouroquinolones Inhibition of DNA topoisomerase 4--> Inhibit DNA replication & inhibit corporation of elastin *higher concentration in breast milk than serum, also may cause photosensitivity & arthropathy |
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In children w/ G6PD deficiency, ______ or _______ may induce hemolytic reactions |
nitrofurantoin or sulfamethoxazole |
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What medications can suppress lactation?
(Galactogogues - Domperidone or metoclopramide (anti-emetic, D2 block) can be used to stimulate lactation) |
estrogens cabergoline, bromocriptine* levodopa antihistamines pseudoephedrines alcohol nicotine bupropion diuretics testosterone |
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Neonatal stomach pH is (acidic/basic/neutral) at birth |
neutral (d/t amniotic fluid) (decreases gastric emptying & transport) *drops w/i 24 hrs (becomes acidic), but takes up to 8 months for normal gastric acid secretion |
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Infants have an __________ total body water percentage |
INCREASED total body water % (increased distribution, decr concentration) *if premature, even higher |
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Infants have lower protein concentration (albumin) (larger Vd), this causes drugs w/ high protein binding affinity to _________ & requires larger loading dose (d/t larger Vd) |
displace bilirubin Ex: sulfonamides (sulfisoxazole)--> kernicterus (jaundice sxs) |
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What else may increase/ worsen bilirubin (bilirubinemia)? |
Hemolysis Nephrotic syndrome Enteropathy |
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______________ (glucoronidation) glucuronyltransferase metabolism (to inactive metabolite) is decreased in infants--> gray baby syndrome (pale, failure to thrive, abdominal distention, poor feeding, respiratory collapse) |
Chloramphenicol |
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Decreased CYP-450---> impaired oxidation in infants---> Reduced clearance of ___________ |
reduced clearance (inc conc, possible toxicity) of diazepam, phenobarbital. theophylline, indomethacin |
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________ use while pregnant/ breast feeding can lead to floppy baby syndrome |
Diazepam |
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Reduced plasma esterase in infants may lead to toxicity w/ ____________ use, d/t reduced elimination |
amino esters (anesthetics, including cocaine) |
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GFR is also reduced in infants--> decreasing the clearance of ___________ (possible toxicity) Which of these may cause red man syndrome? |
decreased clearance of; Digoxin penicillin vancomycin--> red man syndrome* aminoglycosides |
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What do you give an infant to close a patent ductus arteriosus? |
indomethacin |
