& Name
Class/Subclass Mechanism of Action (MOA)
Drugs For Peptic Ulcers ABDE Therapeutic Uses & Specificity
Toxicity and Side Effects
H2 blockers
H2 Histamine Agonist blocks parietal cell H2 receptors.
T1/2 1.5 to 3 hrs. Excreted almost unchanged in urine. Tachyplaxis occurs in several days ( efficacy 50%) not good for long-term use.
Inhibits both fasting and stimulated acid secretion but not circadian rhythm of basal acid secretion. Peptic ulcers.
Cimetidine
Ranitidine Famotidine Nizatidine Antacids
Rebound hypersecretion upregulation of receptors. Diarrhea, headache, myalgias, skin rash all uncommon. One of the dirty dozen a lot of drug-drug interactions via inhibition of microsomal enzyme system. Impotence and gynomastia in large doses. Some inhibition of microsomal enzyme system. Cardiac arhythmias. Expensive and lots of side effects PRN for pain.
Aluminum hydroxide, magnesium hydroxide, Al-Mg hydroxide, calcium carbonate
Proton Pump Inhibitors
Irreversibly inhibits ATPase hydrogen pumpmust replace pump (4%/hour). T1/2 only 0.5 to 1.0 hour but effects last for up to 24 hours. Give before morning meal. If need to increase dose, give second dose before evening meal. GEERD Peptic Ulcers.
Headache, rash, and diarrhea occur rarely.
Omeprazole
Inhibits CYP 2C19phenytoin metabolism. Binds to R factor.
Lansoprazole Defense Agents Sucralfate Bismuth Misoprostol Antimicrobials
Coats. Coats/weak antibiotic. Prostaglandin analogue. Work best at pH.
Use with a PPI (double dose) when can't DC NSAID.
Diarrhea in 30-40% of pts.
Metronidazole, tetracycline, amoxicillin
Prokinetic Drugs Cisapride Metrochloperamide Selective COX-2 inhibitors
Not effective after 3 months. Not effective after 6 months. Night time relief.
problems with drug-drug interactions. Parkinsonian-type side effects.
Celecoxib, rofecoxib
Non-selective COX Inhibitor combined with a defensive agent
Diclofenac/misprostal
VITAMINS AND TRACE MINERALS
Vitamin/Mineral
RDA or Therapeutic Dose
RDA directly proportional to am't of exposure to UV light
Toxicity and Toxic Dose
Megadose Toxicity (know) hypercalcemia
Therapeutic Uses
Deficiency
Vit D resistant Rickets def in enzyme that activates Vit D by converting it to Calcitrol can give megadose of Vit D or just give Calcitrol Inadequate sunlight def Xenical (orlistat) reduces absorption
Vitamin D
Vitamin E
Thiamin (B1) Vitamin K
RDA directly proportional to intake of polyunsaturated fatty acids Recommendation is 200-800 IU (10-50xRDA of 12-15 IU) RDA directly proportional to caloric intake Minimum dose (5 mg) = 60-100x RDA
No serious SE Diarrhea and Headache
May reduce build-up of atherosclerotic plaques in coronary arteries and protect against stroke and heart disease
Antagonize coumarine anticoagulants (stimulates production of clotting factors)
Niacin
Large doses reduces levels of blood lipids
Folic Acid
2x RDA( 400 g/d)
ALL premenopausal women reduce risk of birth defects (NTDs) May also reduce risk of heart disease by lowering homocysteine
Vitamin C
Recommended 250-500 mg/d doses (5-10x RDA of 50-60 mg)
Nontoxic (water soluble) Diarrhea
Megadose Toxicty (know) Diarrhea, kidney stones, sickle cell crisis, transient infertility, altered renal secretion of weak acid/bases
May reduce build-up of atherosclerotic plaques in coronary arteries and protect against stroke and heart disease
May be seen w/ loss of proximal or distal small intestine (& colon) sites of absorption Antibiotics (prolonged and broad spectrum) kill GI microbes necessary for synthesis Seen when corn is main staple low in niacin, bound niacin (no availability), low in tryptophan (aa used to make niacin), low in B6 (required for niacin synthesis) Penicilliamine, Hydralazine, Isoniazid chemically complex w/ B6 and inactivates it (dual def w/ B6) Birth Defects (spina bifida) Folate-responsive schizophrenia due to def in enzyme which makes 5-methyltetrahydrofolate methyl donor in conversion of homocysteine to serine 50100xRDA folate dec buildup of urinary homocysteine Supplement in elderly with unbalanced diets (dec in fruits/veggies) Loss of small intestine (site of absorption)
Beta Carotene (precursor to Vitamin A)
Used to be recommended as antioxidant, but study increases risk of lung CA & death in susceptible people (smokers, asb)
Xenical (orlistat) reduces absorption
VITAMINS AND TRACE MINERALS
Vitamin/Mineral
RDA or Therapeutic Dose
Toxicity and Toxic Dose
Megadose Toxicity (know) teratogenic alterations of face, head, brain, heart risk increases @ doses >10,000 IU/day thickening of leg bones Megadose Toxicity (know) severe (maybe irreversible) sensory neuropathy
Therapeutic Uses
Deficiency
absorption depends on binding to cellular retinol binding protein (CRBP) located in small intestine if missing deficiency
Vitamin A
Vitamin B6 (pyradoxine) Vitamin B12 (cobalamin)
Vitamin B2 (Riboflavin)
Biotin
Penicilliamine, Isoniazid Hydralazine, chemically complex w/ B6 and inactivates it (dual def w/ niacin) Pernicious Anemia (megaloblastic) Seen in vegetarians (no milk products) Seen alcoholics (if deficient in B12 & folate supplement w/ B12 1st to avoid irreversible neurologic damage) Terminal ileum & gastric resection loss of IF and absorption site Can be seen w/ certain drugs (Chlorpromazine, TCAs) block rxn [phosphorylation of B2 to FMN by flavokinase] which is necesssary for absorption Antibiotics (prolonged and broad spectrum) kill GI microbes necessary for synthesis
Name
LAXATIVES Bulk forming agents
Class/Subclass & Mechanism of Action (MOA)
Absorbs and retains water volume and transit time.
ABDE
Therapeutic Uses & Specificity
Toxicity and Side Effects
Gentle see results in to 3 days.
Dietary fiber, psyllium, methylcellulose, polycarbophil
Saline Cathartics
DOC for irritable bowel. Good for pts. on low-residue diets, postpartum, diverticular dz., spastcic colon, and hemorrhoids. Only good for acute evacuation for endoscopy and drug/toxin OD.
Should be introduced gradually to avoid impaction.
Magnesium sulfate, hydroxide, and citrate, sodium phosphate
Contact Cathartics Bisacodyl Bisacodyl tannex Senna
Non-absorbable anions and cations pull water out of the bowel. Produces a watery stool. Most work by gut mobility.
Not gentle see results in 1-3 hours.
Dehydration. Magnesium can impair renal function in the elderly, children, and patients in renal failure. The most often abused class, should not be used for more than 1 week. Turns urine pink/red. (Just in time for Valentines Day.) Hepatotoxic in large doses not to be used with children under 10 and pts. with colon ulcers. Turns urine orange @ pH and pink @pH. In breast milk, not for nursing mothers. Major side effect is fluid and electrolyte loss. Violent Uterine and abdominal contractions.
Used for colon surgery and X-ray exam.
Only 5% absorbed. See results in < 6 hrs.
Enema preparation.
Must be activated by gut flora.
Castor Oil Cascara Other Lactulose
Activated by pancreatic lipase. Reduces net absorption of water and electrolytes.
See results in 2 hours.
Osmotic effect in S.I. and also broken down in the gut to formic and acetic acids (also exert osmotic effect).
Good for routine pugation, but costly. Also use to treat NH3 buildup in liver and renal failure. Donate proton to NH3 NH4+ can't be reabsorbed.
Can't be used in patients that are on a low galactose diet.
Docusates
Minimal laxative effects @ recommended dose.
See results in 1-3 days.
intestinal absorption of other drugs. Do not give with lubricating oils foreign body rxns. Should not be used orally lipid pneumonia and fat soluble vits. Kaolin-pectin water and electrolyte loss.
Mineral oil ANTIDIARRHEALS Hydrophilic Agents/Absor bents
Enemas are reasonable use.
Absorbs water fluidity.
Kaolin-pectin, bismuth subsalicylate
Opiates
gut ...