Pharmacy Technicians Course. LaGuardia Community College

Gastrointestinal System (GI tract)Is a long tube that consists of the mouth, esophagus, stomach, small intestine, large intestine, rectum and anusSeveral organs empty into the GI tract. These include the liver, pancreas, and the gall bladder with the salivary glandsThe main function of the GI tract is digestion and absorption of nutrientsThe movement of the smooth muscles in the GI is called peristasis and propels food in the forward direction

Mouth and oral cavityTeeth normally masticate food which increases the surface area for digestive enzymes to workSalivary amylase is secreted and begins the digestion of starch and complex carbohydrates into disaccharides and trisaccharidesThe oral cavity is also called the pharanyxEsophagus delivers the food to the stomachStomach The stomach further processes the food into a semisolid substance called chymeParietal cells of the stomach also secretes HCL HCL activates pepsinogen into active enzyme called pepsin.Pepsin begins the breakdown of proteins in the food into amino acid peptidesParietal cells also secrete intrinsic factor which is important for absorption of vitamin B12 in the ileumBicarbonate in the mucus in the stomach is present to protect the lining of the stomach from the low pH of the acid environmentSmall IntestineDuodenum is the part of the small intestine where most of the digestion occursPancreas secretes alkaline pancreatic juice which contains an amylase which further breaks down sugars, chymotrypsin (which will break down proteins), lipases (which will break down fats)Additional the liver produces bile acids and the gallbladder stores the acids until needed. When food enters the duodenum CCK is release and the gallbladder pumps bile acids into the duodenumBile acids solubilize the fats into micelles to increase the surface area for pancreatic lipase to work.End products of DigestionCarbohydrates to glucose and/or FructoseProteins to amino acids and same peptidesFats to fatty acids and glycerolFats are transported via chylomicrons to the liver where VLDL, and LDL are secretedThe enterocytes of the small intestine will absorb these and the mesenteric veins will empty into hepatic portal vein which carries nutrients to the liver (first pass) Large IntestineThe main function of the large intestine is to absorb water and electrolytes into the blood streamIf too much water is absorb the result is constipationIf too little is absorbed the result is diarrheaDisorders of the GI systemGastroesophegeal reflux or GERD caused by abnormal amounts of acid in stomachor esophageal sphincter functionDefective prostaglandin synthesis and defective bicarbonate production (NSAIDs, and ASA)Tx: antacids containing calcium carbonate (TUMS) or aluminum and magnesium hydroxide (MAALOX)Alternatives are PPI (proton pump inhibitors)Nexium (esomeprazole)Protonix (pantaprazole)Aciphex (rabeprazole)Prilosec (Omeprazole)Drugs work on the parietal acids to block HCL secretionNausea and Vomiting (NV)Common seen in pregnancy, overeating, alcohol consumption, illness, bacterial or viral gastroenteritis, food poisoning, and post operative statesA common side effect to opiate medicationsA common side to diabetic gastroparesisDrugs that are used to treat NV5 HT3 agonist : ondansetron (Zofran), granisetron (Kytril) the gold standard in NV tx in chemotherapyDopamine blockers: Prochlorperazine (Compazine): classical used in the morning sickness. Dopamine blockers/GI stimulant: Metoclopramide (Reglan) used in tx of diabetic gastroparesisMalabsorption diseasesCeliac disease: autoimmune disease of the small intestine where there is a senstivity to glutenGluten also known as wheat protein is a trigger for this reaction.Results in severe diarrhea and profound electrolyte loss Malabsorption of fat soluble vitamins (bleeding disorder)Other names for this disease is nontropical sprue, or Gluten insensivityTropical Sprue: a disease causing the villi of the small intestine to stop absorbing nutrients. Can be fatalProfound loss of all nutrients and fat soluble vitaminsBelieve to be caused by a bacterial factor.Treated with a course of Abx: DoxycyclinePancreatic disease including pancreatic cancer, pancreatitis and cystic fibrosisCholestatic jaundice

ConstipationResults from:Inadequate water intakeInadequate fiber intakeChanges in lifestyleLack of exerciseDrugs like opiatesAbuse of laxativesTherapy of constipationBulk forming laxative commonly include fiber which increases bulk of stool to stimulate GI tract. Includes: Metamucil (psyllium)Emollient makes the fecal matter slippery includes mineral oil enema (Fleet mineral oil)Surfactants makes the feces more soft: Colace (docusate sodium)Saline laxative powerfully draws water into the stool. Includes magnesium citrate (Citroma), and sodium phosphates (Fleet Phosho Soda)Evacuants work similar to saline laxatives: Golytely (PEG with lytes)Stimulants: triggers the nerve that control bowel movements to work. Includes bisacodyl (Dulcolax) and Senna (sennakot)Therapy of DiarrheaDiarrhea is a loss of water and electrolytes as a result of infections or inflammation of the large or small intestine.Bloody diarrhea is sometimes called dysentery and result in infection with salmonella (Typhus fever), shigella, or E. Coli Treated with Abx: fluoroquinolones or BactrimCholera is disease of the third world where a spirochete, called Vibrio Cholerae infects the small intestine and its toxin produce profound loss of water and electrolytes. Potentially fatal if untreated with Abx and IV hydration

Diarrhea can be treated with fiber Absorbs water from the GI and swells to provide bulkExamples are Metamucil (natural psyllium hulk) or fiber from fruits and vegetablesCan be treated with narcotics and narcotic derivativesOpium Tincture sig: 0.25 ml-0.5 ml bid as needed to limit bowel movements. Caution: tincture as high concentration. Can result in overdose.Lomotil (Diphenoxylate/Atropine) CVImodium (Loperamide, a meperidine derivative)

Liver DiseaseLiver pathology includes hepatitis, cirrhosis, and cancerDamage to the liver can also occur from drugs. Drugs that can cause liver damage are: acetaminophen (Tylenol), amiodarone (Cordarone), anabolic steroids, isoniazid, oral contraceptive agents, methotrexate, allopurinol (Zyloprim)HepatitisInflammation of the liverCaused by viruses in most cases. Hepatitis B and C is life long and can lead to hepatocellular carcinoma and cirrhosis of the liver. CMV can also cause hepatitisCan be caused by drugsAlcoholHepatitis A virus (HAV)Transmitted by oral-fecal route in endemic areaSymptomic therapy; not life longPrevented by vaccination: Havrix (GSK) and Vaqta (Merck)Hepatitis B (HBV)serum hepatitisTransmitted by blood or infected bodily fluid contact with mucus membranes or by blood transfusions or by poorly sterilized medical devices (needles)Can be transmitted to a fetus by an infected motherNew born babies are vaccinated at birthRecombivax 0.5 ml IM or Energix 0.5 ml IMhepatitis B surface antigen (HBsAg) produced in yeast cellsAcute infection causes vomiting, abdominal pain, jaundice and sometimes hepatic failure and deathChronic infection leads to cancer and cirrhosisTherapy of HepatitisTherapy is complex and involved drug, antibody level and viral load monitoringAntiviral drugs (similar to HIV drugs)Lamivudine (Epivir)Adefovir (Hepsera)Tenofovir (Viread)Entacavir (Baraclude)Interferons are drugs that modify the immune response to the viral infectionInterferon alpha (Intron A, Roferon)Interferon alpha (peglyated): Pegasys give weeklyThese drugs cool the immune reaction to viral does not clear the infectionCirrhosisEnd stage liver diseaseFibrosis of the sinusoids of the liverComplications: bleeding, CNS edema, renal dysfunction, ascites, hypoglycemia, hepatic bone disease (osteodystrophy), bleeding into the GI tract from varicesTerminal conditionChronic hepatitis and carcinoma leads to cirrhosisExtreme alcohol consumptionLiver Transplant is only cureAmino AcidsThe body can produce 11 types of amino acids, referred to as nonessentialThere are 9 types of amino acids that the body requires, but cannot produceThese are referred to as essential amino acids (See table 23.9)Essential amino acids have to be derived from food intake19Vitamin DHelps with the absorption of calcium from the intestine to make stronger bones and teethDeficiency causes metabolic bone softening:Called rickets in childrenCalled osteomalacia in adultsDRI is 5 g/day (ages 1950) for both males and femalesDRI is 10 g/day (ages 5170) for both males and females20Vitamin KNecessary for blood coagulationControls formation of coagulation factors II, VII, IX, and X in the liverAlso needed for calcium uptake in bonesCan be used as an antidote for coumadin overdosesDeficiency is rareDRI is 120 g/day for males and 90 g/day for females21Vitamin B1 (thiamine)Necessary for carbohydrate metabolismDeficiency causes the disease beriberiAffects the peripheral neurologic, cerebral, cardiovascular, and GI systemsDRI is 1.2 mg/day for males and 1.1 mg/day for females22Vitamin B3 (niacin)Important in oxidation-reduction reactionsVital in protein metabolismDeficiency leads to the disease pellagra:Affects skin, mucous membranes, GI, and brain/CNS systemsCauses photosensitive rash, scarlet stomatitis, glossitis, diarrhea, and mental aberrationsDeficiency found in diets high in cornDRI is 16 mg/day for males and 14 mg/day for females

23Vitamin B6 (pyridoxine)Needed for:Red blood cell formation- Antibody productionCell respiration- Cell growthConversion of tryptophan to niacinHelps convert stored carbohydrate to glucose to maintain normal blood sugar levelsSynthesis of neurotransmitters such as serotonin and dopamineDeficiency can cause:Anemia similar to iron-deficiency anemiaDecreased antibody productionSuppressed immune responseSymptoms such as dermatitis, a sore tongue, depression, confusion, and convulsions

24Vitamin B9 (folic acid)Important for:Energy production-Formation of red blood cellsStrengthening immune systemPromoting healthy cell division and replicationProtein metabolismPreventing depression and anxietyDeficiency can be serious and may result in:Anemia- ApathyDigestive disturbances- FatigueGrowth impairment- InsomniaLabored breathing- Memory problemsParanoia- Weakness

25Vitamin B12 (cyanocobalamin)Needed for healthy nerve cells, to make DNA, and for the formation of RBCsDeficiency leads to irreversible nerve damageSigns and symptoms include:Fatigue- weaknessNausea- constipationFlatulence- loss of appetiteweight loss - depressionConfusion- poor memory

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