Week – 4 Pharmacology

Drugs and Disorders of the Gastrointestinal Tract

Nutritional Supplements chapters – 25 and 20

GI TRACT – A DEFINITION Long, hollow tube from the mouth to the anus primary purpose - to convert food into chemicals that can be

used by the body Food’s pathway through GI tract … … Mouth Esophagus Stomach Small Intestines

[gallbladder, liver, pancreas enzymes]Large Intestine Anus

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HOW DRUGS WORK IN THE GI SYSTEM

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1. they increase or decrease function by changing muscle tone, or changing the level of secretions (for example … decreasing the level of acid-production to prevent or cure ulcers)

2. Increase or decrease ‘emptying time’ (the time it takes food to pass through the stomach/GI tract) … this is accomplished by altering ‘peristalsis’

3. Replacement of enzymes (in cases of deficiency)

LIFESTYLE MODIFICATIONS FOR GI PROBLEMS

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Foods to avoid Tomato Orange/Grapefruit juice ETOH Caffeine Chocolate peppermint

Don’t over eat, maintain ‘normal’ weight Avoid eating within 2 hours of bedtime Don’t smoke Elevate head of the bed 6-8 inches (gravity can help empty the

stomach!)

GASTRIC CONDITIONS/ENVIRONMENT

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Acidic environment is needed in the stomach for enzymes to work and inhibit or kill microorganisms found in food and other materials that are ingested

Sometimes acid level is too high and can erode the stomach wall/lining

Worry and Stress increase secretions in the stomach This can lead to ulcers

Gastric ulcer = Peptic ulcer = stomach ulcer (all the same) ‘Deodenal ulcer’ is found at the junction of stomach and duodenum

ULCERS – GENERAL INFO

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Goal of treatment: to alleviate symptoms, promote healing prevent complications, and prevent recurrence.Heliobacter pylori has been found in >75% of peptic ulcer

disease! (the remaining 25% caused by NSAID & ASA use) Opportunistic infection at the site of the ulcer.

Smoking slows the healing of ulcers … it increases acid production

Eating multiple small meals decreases changing acid levels Drugs (ASA and NSAID’s) can cause irritation to the stomach

MEDICATIONS TO TREAT ULCER

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All these work together to eradicate the microorganism Helicobacter pylori and reestablish an intact lining of the stomach by neutralizing excess hydrochloric acid.Antacids (neutralizes acid that is currently present)Mucosal protectants (forms a protective barrier on the

surface of ulcerated tissue)Antibiotics Antisecretory Agents (reduce excess acid-production)Antispasmodics

ANTACIDS

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Alkaline compounds used to neutralize HCl acid in the stomach

Used as prophylaxis for stress-induced ulcers Relieves symptoms of Gastroesophageal Reflux Disease

(GERD) Protect intestinal mucosa by neutralizing acid Poorly absorbed (this is good!), therefore they do not alter

systemic pH when used properly

ANTACIDS CONTINUED

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More effective when taken on a regular basis Can be dosed up to 7 times per day (before meals, after meals,

and bedtime) Come in liquids, chew tabs, and a few swallow tabs or caps. Short duration of action … ~ 30 minutes on empty stomach Chronic use can produce acid rebound Classified by formulation (aluminum, magnesium, etc)

ANTACID FORMULATIONS

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Aluminum (side-effect = Constipation) Calcium (side-effect = Constipation) Magnesium (side-effect = Diarrhea) Sodium (can change systemic pH – dangerous choice) Aluminum & Magnesium combo is common because these

cancel out each other’s negative side-effects … very effective! Choose product with care, based on patient’s profile NOTE - sodium bicarbonate changes the pH (acid/base

balance) in the body and can lead to other problems

PATIENT EDUCATION FOR ANTACIDS

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Chewable antacids should be taken with a full glass of water or milk to help with absorption

Shake liquids well and don’t follow with additional liquids … this dilutes the antacid, reducing its effect

Antacids and H-2 blockers should be taken at least an hour apart, antacids first.

careful when taking other medications, these can interfere with absorption of other drugs

Examples of Antacids … Mylanta, Maalox Tums, Rolaids

ANTISECRETORY AGENTS

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These Decrease the secretion of gastric fluids (acid) Two types

H2-receptor antagonists (H2) Zantac (ranitidine) Pepcid (famotidine)

Proton pump inhibitors (PPIs) Prilosec (omeprazole) Previcid (lansoprazole) Nexium (esomeprazole)

* NOTE – see how the generic drug names within the same class tend to end with the same suffix? This is very helpful in learning drugs!

H2-RECEPTOR ANTAGONISTS

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Inhibits interaction of histamine (H2) at the H2-receptors Histamine receptors in gastric mucosa mediate the secretion

of gastric acid and pepsin Work to directly inhibit the acid secretions Not affected by food (ok with or w/o meals) best to take at bedtime (acid production peaks during the

overnight hours!) Well tolerated, low incidence of side-effects Very effective for GERD Available as OTC and RX

PROTON PUMP INHIBITORS (PPIS)

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Inhibits chemicals essential to Gastric-acid production (H+ and K+ ions, which generate gastric acid)

For SHORT TERM treatment of benign gastric ulcers and GERD!

often used in combo with antibiotics for H. pylori to promote healing and prevent reoccurrence

Should only be used for confirmed active ulcers and erosive esophagitis.

Side effects are relatively rare (headache, abdominal pain, diarrhea, nausea, constipation are possible)

PROTECTANTS

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Carafate (sucralfate) Adheres to ulcerated tissue, forming a barrier Soothing effect like Antacids Does not alter pH Take on empty stomach

Cytotec (misoprostol) Protects from irritation of certain medications, like NSAIDS Used to prevent ulcers in patients who must take medications that

can cause gastric irritation Take on a empty stomach

ANTIBIOTICS

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Commonly used to treat Heliobacter pylori Treatment with two antibiotics decreases resistance Used in combo with bismuth-salts to prevent bacteria from

attaching stomach wall. Antibiotics that are commonly used …

Amoxicillin Tetracycline Metronidazole (Flagyl) Clarithromycin (Biaxin)

antisecretory agents often used in combo (PrevPak) See table 25-6 in text on page 503

ANTISPASMOTICS

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These relax GI smooth-muscle tissue, reducing cramping and spasms (IBS)

Not as commonly used as the previously mentioned medications due to more frequent Side-Effects Cause problems in glaucoma & urinary retention patients

more Side Effects … Visual disturbances Confusion in demented patients Changes in heart rhythm Headache Insomnia

VITAMINS, MINERALS, AND GENERAL NUTRITION

CHAPTER - 20

“YOU ARE WHAT YOU EAT”

FOOD & NUTRITION BOARD OF THE NATIONAL ACADEMY OF SCIENCE

VITAMINS: CHARACTERISTICS Organic in nature Very small amounts needed daily Preformed in the diet or synthesized by intestine NECESSARY for body’s normal growth & function Store in dark containers in a cool place NECESSARY for enzymatic reactions Common vitamin-deficiency symptoms include … - aches/pains - general, overall ‘poor’ feeling - tiredness/low energy

‘FAT SOLUBLE’ VITAMINS

‘WATER SOLUBLE’ VITAMINS

(2) General Groups1) Those that release energy from food (thiamine, riboflavin)

2) Aides to red blood cell formation (folic acid, Vitamin B12)

FOLIC ACID IN PREGNANCYo extremely important supplement for women!o Reduces the incidence of neural tube birth defects such

as … * Spina Bifida * anenchephaly * encephaloceleo … essential for DNA formationo Women of childbearing age should consume 0.4-mg/day

of Folic acido Also known as ‘Folate’

MINERALSo Iron – (oral, injectable)o Calcium -

(lactate/glucomate/chloride/carbonate)

o Phosphorouso Potassium – (chloride/gluconate)

oFreely found in soil, plants used for food, and sea food.oOnly required in trace amountsoRole in transmission of nerve impulsesoControl of cardiac rhythm

1) The disease that develops due to a vitamin overdose is…?

2) A non-organic material found in the Earth’s crust is a…?

QUESTIONS!

ANSWERS!

1) Hypervitaminosis

2) Mineral

HAVE A GREAT WEEK, THANKS FOR YOUR INPUT!

Remember, you are welcome to submit any and all questions to me as they arise … I check my email daily, as well as the ‘VIRTUAL OFFICE’.

Thanks again, -Dr. C