Do h2antagonists go thru first pass
Yes, cimetidine/ranitidine/famotidine go thru with 50% bioavailability- nizatidine has little first pass metabolism. Katzung 1083.
Physiology of acid secretion part 1
Vagal nerve stimuli of acetylcholine and gastrin release into blood bind to parietal cell receptors increasing calcium and stimulating proton pump acid secretion. Katzung 1081.
Physiology of acid secretion part 2
Gut endocrine cells ECL gastrin and acetylcholine receptors stimulate histamine release which binds to h2 receptor on parietal cells increasing cAMP which stimulates acid secretion. Katzung p 1082.
Use antacids cautiously with what diseases
Renal failure, heart failure, or HTN. Katzung p1083.
Pharmacodynamics of h2 inhibitors
Competitive Antagonists inihibitors parietal cell h2 receptors and suppress basal and meal-stimulated acid secretion, dose dependent. P 1084.
Administration of h2 inihibtors
Work best for nocturnal acid secretion. Greatest coverage for 10hrs so give twice daily, take before meals. P 1084.
Which promotes better ulcer healing: PPI or H2 antagonist
PPI- so give if some if it takes NSAIDS and gets ulcers p. 1085.
How should h. Pylori be treated
14-day PPI 2xdaily; clarithromycin, 500mg BID, & either amoxicillin 1gm BID, or metronidazole 500mg BID. Then PPI daily for 4-6 wks. p 1085.
When would u give h2 antagonists with h. Pylori
For the minority of pt that h. Pylori is not eradicated, may give h2 antagonist at bedtime for ulcer prevention p. 1085.
Drug interactions of h2 antagonists
Interferes with P450, will prolong half life of drugs with this metabolism pathway. P. 1085 katzung
Adverse effects of h2 antagonists
Mental status changes, nosocomial pneumonia, gynecomastia, male impotence, galactorrhea in women, possible blood dyscrasias, cross placenta and breast milk. P. 1085 katzung.
Pregnancy category of PPI
No harm to animal fetus but no test on human, cat B? P, 1088.
Nutritional adverse affects of PPI
Osteoporosis, life threatening hypo magnesia with secondary hypocalcemia if long term usage. P. 1088
What does PPI do to clopidegral/plavix
Reduce activation, p. 1089.
Acetylcholinestetase inhibitor that enhances emptying p. 1092.
Adverse effects of metocloprsmdi de/zofran
Restlessness, drowsiness, insomnia, anxiety, and agitation p. 1092.
What antibiotic promotes gastric motility
Macrolides, erythromycin. katzung p. 1092
What are Bulk forming laxatives/polycarbophil
Indigestible, hydrophilic colloids that absorb water forming a bulky
Emollient gel that distends the colon/promotes peristalsis.
S/E of bulk-forming for laxatives/polycarbophil
Increased bloating and flatus, katzung p. 1093.
What are Osmotic laxatives
Soluble but nonabsorbable compounds that increase liquidity due to obligate increase fecal fluid. Katzung p. 1093.
What are purgatives
Mag citrate & sodium phosphate: they are high dose osmotics & produce evac in 1-3hrs. Katzung p. 1093.
Administration of polyethylene glycol/miralax
For bowel cleanse take 2-4L over 2-4 hours: to prevent constipation take 17gm mixed with water: does not produce cramps/flatus like sorbitol/lactulose. Katzung p. 1093.
Examples of anthraquinone derivatives stimulant laxatives
Aloe, senna, and cascara natural; in plants. Katzung p. 1093.
S/E of chronic anthraquinone derivatives
Brown colon "Melanosis coli". Katzung p. 1093
What laxative is safe for long term use
Bisacodyl katzung p 1093.
What are 2 selective antagonists of opioid receptor for opioid induced constipation
Methyl naltrexone bromide and albino pan. Katzung p. 1094.
When to use antidiarrheals
To control chronic diarrhea caused by conditions such as IBS & IBD. Katzung p. 1094.
When to not use antidiarrheals
Bloody diarrhea, high fever, systemic toxicity, or worsening symptoms. Katzung p. 1094.
What do you use for chronic and pain in IBS
Low dose of tricyclics antidepressants(amitryptiline) they affect gi motility and secretion reducing stool frequency and liquidity. Katzung p. 1096.
S/E of antispasmodic
Anti cholinergics effects, dry
Mouth, visual disturbances, urinary retention, and constipation. Katzung p. 1096.
What do 5-HT 3- receptor blockers affect/alosetron.
Nausea, bloating, pain, inhibits colon motility especially left colon increasing colonic transit time. Katzung p. 1096.
What is serious side effect of alosetron
Constipation: possibly requiring surgery. Katzung p. 1096.
What is primary action of 5-Asa/aminosakicylates
Blockade of prostaglandin synthesis by inhibition of cycloixygenas r. Katzung p. 1102.
What's considered first line of defense for ulcerative colitis
5-Asa, depending on location may need to give as enema or a mesalamine. P. 1102 katzung
What's the most common drug for IBD
Glucocorticoids/prednisone katzung not useful for maintaining remission p. 1103
What med is important in reduction and maintenance of ulcerative colitis and chrons
Azathioporine and 6-mp
What are advers effects of azathioporine and 6-mp
N/v, bone marrow suppression, and hepatic toxicity: lab monitor with cbc and liver fx katzung p. 1104
what is gonadarche
the change in ovarian function at puberty thereby begins estrogen production to induce endometrial changes and periodic bleeding. katzung p. 715
what triggers ovulation
follicles begin to enlarge in response to FSH; 5-6 days the dominant follicle enlarges and cells multiply due to LH; the cells synthesize and release estrogen which inhibits FSH release; the estrogen reaches a peak mid cycle (14 days) and the granolas cel
what are the major estrogens produced by women
estradiol, estrone, estriol. katzung p. 717
which estrogen is excreted in urine and can be tested to assess fetal well-being
estriol, katzung p. 717
pharmacokinetics of estrogen
binds strongly to alpha2 globulin, low affinity for albumin, bound estrogen is unavailable for diffusion into cell; converted into estriol and estrone by liver; excreted in bile; crosses breastmilk; minimize first pass affect to reduce risk for increase c
what are 2 types of preparations for oral contraceptives
1. combo of estrogen and progestins. 2. continuous progestin without concomitant estrogen. katzung 726.
what are 3 categories of combo OC
monophasic- constant dosage of both components.
biphasic and triphasic- dose of 1 or both components is changed 1-2 times during cycle. katzung 726.
effects of OC on uterus
after long usage some hypertrophy and polyp formation. cervical mucus may be thicker and less copious. OC with smaller amts of estrogen may produce more glandular atrophy and less bleeding. katzung 727.
effects of OC on breasts
stimulation and some enlargement may occur especially when on estrogen containing OC. lactation suppression, so give in some doses. katzung 727.
mechanism of action of OC
selective inhibition of pituitary function and in turn inhibits ovulation. katzung 727
are estrogens a feel good hormone
yes, they are even being used to treat postmenapausal tension, post partum depression, and climacteric depression. katzung 727.
effects of OC on blood
anemis, folic-acid anemias, thrombus, increase iron, increase blood clotting. katzung 727.
effects of OC on liver
alterations in hepatic drug excretion. reduce bile flow and may cause increase in gallbladder disease. katzung 728
effect of OC on carb metabolism
reduce the rate of carb absorption. increase insulin level. cause carb intolerance. katzung 728
effects of OC on cardiac
increase cardiac output and b/p. katzung 728
effects of OC on skin
progestin OC increase sebum production and in turn hair growth, darken skin color, acne
estrogen OC decrease sebum production. katzung 728
what meds can decrease effectiveness of OC
antibiotics that affect hepatic metabolism or phenytoin. katzung 728
mild adverse effects of OC- usually no dc meds necessary
too much estrogen: Nausea, mastalgia, bleeding, edema.
migraines, increase sed rates, change in serum proteins, evaluate thyroid, adrenal, and pituitary function. katzung 728
moderate adverse effects of OC- may need to dc meds
breakthrough bleeding-biphasic and triphasic decrease breakthrough bleeding. weight gain- may need to decrease progesterine, bacteriuria d/t ureteral dilation. katzung 729
severe adverse effects- dc meds
thromboembolism r/t estrogen content, MI d/t glucose intolerance/decrease HDL/increase LDL/increase platelet aggregation. katzung 729
contraindications of OC
hx of cardiac disease, thrombi, undiagnosed heavy vaginal bleeding, breast tumors, estrogen dependent neoplasms, liver disease, eczema, migraines, diabetes, optic neuritis. katzung 730
when wold progestin only be helpful
puts with hx of hepatic disease, HTN, psychosis, mental retardation, or thrombi. katzung 730
120-135/80-89. Katzung 170
140/90. Katzung 170
Stage 1 htn
140-159/90-99. Katzung 170.
How do diuretics work
Deplete body of Na and reducing blood volume. Katzung 171
How do sympathoplegic agents work
Reduce peripheral vascular resistance, inhibit cardiac function, and increase venous pooling. Katzung 172
How do direct vasodilators work
Relax smooth muscle, thus dilating resistance vessels. Katzung 172
How do Angiotensin blockers work
Reduce peripheral vascular resistance. Katzung 172.
When would a powerful loop of henle diuretic/furosemide be used
Severe htn when multiple drugs with Na retaining properties are used; in renal insufficiency when glomerular filtration rate less than 30-40ml/min; cardiac failure or cirrhosis which Na retention is marked. Katzung 173.
What drugs can increase blood pressure
Sympathizing tic decongestants, NSAIDS, oral contraceptives, and some herbal mess. Katzung 186.
Stage 2 htn
160/100. Katzung 170.
What are the prototype drugs of loop diuretics
furosemide & ethacrynic acid p. 258
What are sulfonamide loop diuretics
Bumetanide & toresmide. pg 258
Pharmacokinetics of loop diuretics
rapidly abosrobed and excreted through the kidneys. effects last for about 2-4hrs. NSAIDS or probenecid may reduce secretion of loop diuretics. p. 258
pharmacodynamic consideration of loop diuretcis
may cause increase in calcium and mag excretion increasing risk for hypomagnesemia but not hypocalcemia due to vitamin d induced intestinal absorption and parathyroid renal asbsorption may be increased. p. 259
What are indication of use of loop diuretics
pulmonary edema, edematous conditions, acute hypercalcemia; hyperkalemia, acute renal failure, and anion overdose. p. 259
Clinical use for thiazides
HTN, heart, failure, nephrolithiasis D/T idiopathic hypercalciuria, nephrogenic diabetes insipidus. p. 261
effects of thiazide toxicity
hypokalemia metabolic alkalosis and hyperuricemia, impaired carb tolerance/hypoglycemia, hyperlipidemia, hyponatremia, sulfa cross-sensitivity, rash, photosensitivity, weakness, fatigue, impotence. p. 261
prototype drug for k+ sparing diurectics
spironolactone/eplerenone or amiloride/triamterene. p. 261.
what is spironalactone
competitive antagonist of aldosterone with a slow onset needing several days before full therapeutic effect.