GI Pharmacology

GI System Introduction

The purpose of the GI system is to take in and digest food, absorb nutrients, and remove undigested wastes from the body The GI system can be divided into the upper GI system and the lower GI system Accessory organs of the GI system are the liver, gallbladder, and pancreas

The upper GI system is from the head to the upper abdominal cavity. It consists of

the oral cavity, pharynx, esophagus, and stomach.

The upper GI system has mucosa, a mucous membrane that

produces thin mucus.

The esophagus connects the pharynx to the stomach, and peristalsis moves

liquids and food particles to the stomach.

The lower esophageal sphincter between the esophagus and stomach prevents

stomach contents from flowing back into the esophagus, and the parietal cells produce hydrochloric acid, and other cells produce pepsin

The gastric mucosa produces mucus to protect the stomach from

hydrochloric acid.

The pyloric sphincter at the distal end of the stomach

keeps contents in the stomach for an hour or so after eating, then opens and moves them towards the duodenum

Diseases that effects GI system are

GE reflux, gastric and peptic ulcers, nausea and vomiting, and drugs are for GE reflux diseases, for gastric and peptic ulcers, and antiemetic drugs for nausea and vomiting

Drugs for Gastroesophageal Reflux Disease

Gerd or heartburn is due to the lower esophageal sphincter allowing hydrochloric acid and stomach contents to reflux into the esophagus causing inflammation and pain To treat GERD, we want to eat small, frequent meals; avoid eating foods that increase the acidity of the stomach; elevate the HOB while sleeping; and avoid stress. Drugs are used to treat conditions when lifestyle changes do not suffice.

Antacid Drugs

Antacids are weak bases that work by neutralizing hydrochloric acid in the stomach. This raises the pH of the stomach and decreases irritation of the gastric mucosa A higher pH inhibits pepsin so that it does not metabolize the gastric mucosa Individual antacid drugs Aluminum hydroxide Calcium carbonate Magnesium hydroxide Sodium bicarbonate: Dissolve in water to treat heartburn at home

Combination Antacids Drugs

Antiflatulant drugs: Simethicone is mixed in to treat intestinal gas or an analgesic drug, aspirin, for pain Alka-Seltzer: Sodium bicarbonate, aspirin Di-Gel: Aluminum hydroxide, magnesium hydroxide Gaviscon Extra Relief: Aluminum Hydroxide, magnesium hydroxide Gelusil: Aluminum Hydroxide, magnesium hydroxide, simethicone Mallox Advanced Maximum strength: Aluminum Hydroxide, magnesium hydroxide, simethicone Mylanta Maximum Strength: Aluminum hydroxide, magnesium hydroxide, simethicone, Rolaids: Calcium Carbonate, Magnesium hydroxide (simethicone) Tums with gas relief: Calcium carbonate, simethicone

H₂ Blocker Drugs

H₂ blocker drugs treat GERD by blocking the action of histamine. Histamine activates H2 receptors on the parietal cells in the stomach, causing them to produce hydrochloric acid H2 blocker drugs block histamine receptors and stop the production of hydrochloric acid. The suffix "-tidine" is common to generic H₂ blocker drugs Cimetidine (Tagmet HB) Famotidine (Pepcid) Nizatidine All H₂ blocker drugs were originally prescription drugs H₂ receptors are the receptors in the mucosa that produce histamine, and by rearranging the chemical structure of a histamine molecule, they developed a drug that would block H₂ receptors and stop the production of hydrochloric acid

Proton Pump Inhibitor Drugs

Proton pump inhibitors reduce the production of hydrochloric acid and raise stomach pH by blocking the final step in acid production by the gastric parietal cell that involves an enzyme known as the proton pump. This effect lasts for 24 hours. Proton pump inhibitors have the suffix "-prazole." Dexlansoprazole (Dexilant) Esomeprazole (Nexium) Iansoprazole (Prevacid) Omeprazole (Prilosec) Pantoprazole (Protonix) Rabeprazole (AcipHex)

Gastric Stimulant Drugs

Gastric stimulant drugs increase the body’s response to acetylcholine, a neurotransmitter that stimulates stomach contractions. This causes the stomach to empty more frequently and keep excess hydrochloric acid from accumulating in the stomach or refluxing upward into the esophagus Metoclopramide (Reglan)

Combination Drugs

This combination drug contains a proton pump inhibitor (omeprazole) and an antacid drug (sodium bicarbonate) to treat GERD, which is Zegerid

Drugs for Gastric and Peptic Ulcer

A gastric ulcer is located in the stomach A peptic ulcer is located in stomach, esophagus, or duodenum An Ulcer forms when irritation or infection removes the protective mucus from the surface of the mucous membrane and pepsin starts breaking down the underlying membrane, forming an ulcer Causes of ulcers include GERD, use of aspirin or NSAIDs, H. pylori infection, use of alcohol, caffeine, or hypersecretion of the stomach H₂ blocker drugs, PPI, prostaglandin drugs, surface protectant drugs, and H. pylori drugs treat ulcers.

Specific PPI for Ulcers

Iansoprazole (Prevacid) Omeprazole (Prilosec) Rabeprazole (Aciphex)

Prostaglandin Drugs

Prostaglandin drugs are used to prevent or treat gastric and peptic ulcers that are caused by taking NSAIDs on a regular basis. Prostaglandin drugs stimulate mucus production to form a protective barrier and stimulate bicarbonate secretion to increase the pH while inhibiting hydrochloric acid secretion. This prevents ulcer formation in patients who need to take NSAIDs on a long-term basis. Misoprostol (Cytotec)

Surface Protectant Drugs

Surface protectant drugs are used to prevent or treat peptic ulcers caused by taking NSAIDs. They are attracted to damaged mucous membranes or areas draining fluid high in protein. They stick to the surface and form a bandage over the ulcer to allow it to heal by protecting it from HCI, bile, and digestive enzymes. Sucralfate (Carafate)

Combination Drugs

Used to prevent the formation of peptic ulcers in patients with osteoarthritis or rheumatoid arthritis who take NSAIDs on a regular basis. They contain a PPI and an antacid drug. SOme also have an NSAID Vimovo (Esomeprazole, magnesium, naproxen) Zegerid (Omeprazole, sodium bicarbonate)

Drugs for H. Pylori Infection

Gastric ulcers can also be caused by H. Pylori, spiral bacteria with flagellae. They inhabit the mucosa and cause peptic ulcers that do not heal. These are treated with different drugs, including antibiotics and PPIs. Antibiotic Drugs (amoxicillin, clarithromycin, rifabutin, tetracycline) Antiinfective Drug (Bismuth) Antiprotozoal Drug (Metronidazole) PPIs (Lansoprazole, omeprazole) Helidac (Tetracycline, bismuth, metronidazole) OMeclamox-Pak (amoxicillin, clarithromycin, omeprazole) Prevpak (amoxicillin, clarithromycin, lansoprazole) Pylera (tetracycline, bismuth, metronidazole) Talicia (amoxiciline, omeprazole, rifabutin)

Antiemetic Drugs

Used to control nausea and vomiting associated with motion sickness and vertigo. Bacterial or viral illnesses can also directly irritate the intestinal mucosa and cause nausea and vomiting Chemotherapy drugs and radiation treatments stimmulate the chemoreceptor zone and vomiting center in the brain. And abdominal sstimulatetemporarily stop or slows peristalsis, causing distention and trigger postoperative nausea and vomiting Patients can take subcutaneous, intravenous, rectal and transdermal drugs for vomiting Antiemetic drugs include anticholinergic drugs, antihistamine drugs, cannabinoid drugs, dopamine antagonists, neurokinin-1 receptor antagonist drugs, phenothiazine derivative drugs, serotonin 5-HT₃ receptor blocker drugs, and other antiemetic drugs.

Anticholinergic Drugs

Block the action of acetylcholine receptors in the smooth muscles lining the GI system. This decreases peristalsis. This drug is a transdermal patch that is placed behind the ear and provides relief from nausea and vomiting for three days. Scopolamine (Transderm-Scop)

Antihistamine Drugs

Block histamine receptors. They also block chemoreceptor trigger zone that is linked to the vomiting center in the brain Dimenhydrinate (Dramamine) Diphenhydramine (Benadryl) Meclizine (Bonine) Promethazine (Phenergan) Diclegis is a combination of doxylamine and the vitamin B6 pyridoxine, which is the only approved drug to treat nausea and vomiting.

Cannabinoid Drugs

Schedule drugs II and III, synthetic versions of marijuana used to treat vomiting caused by chemotherapy drugs. Dronabinol (Marinol, syndros) Nabilone

Dopamine Antagonist Drugs

Blocks dopamine receptors in the chemoreceptor trigger zone and stops nerve impulses to the vomiting center in the brain. These treat postoperative nausea and vomiting Amisulpride (barhemsys) Metoclopamide (Reglan)

Neurokinin-1 Receptor Antagonist Drug

Block substance P in the vomiting center in the brain and its neurokinin 1 receptors on nerves in the intestine. These drugs are used to treat postoperative nausea and vomiting or the nausea and vomiting that occurs with chemotherapy for cancer Aprepitant (Cinvanti, Emend) Fosaprepitant (Emend) Rolapitant (Varubi)

Phenothiazine Derivative Drugs

Phenothiazine derivative drugs have an antiemetic effect for nausea and vomiting They belong to the antipsychotic drug category and treat bipolar disorder, psychosis, and schizophrenia. Chlorpromazine Prochlorperazine Promethazine (Phenergan)

Serotonin 5-HT3 Receptor Block Drugs

Serotonin (5-HT) is a neurotransmitter. The Ht3 receptors are a selective group of serotonin receptors that are found in the brain's vagus nerve, which extends from the brain to the abdomen. Chemotherapy drugs and radiation therapy cause the release of serotonin into into the vomiting center of the brain and intestine Serotonin 5-HT₃ receptor blocker drugs block the release of serotonin in those areas to prevent nausea and vomiting Dolastron (Anzamet) Granisetron (Sancuso, Sustol) Ondanestron (Zofran, Zuplenz) Palonosetron (Aloxi)

Other Antiemetic Drugs

Perphenazine and prochlorperazine are antipsychotic drugs that have an antiemetic action Promethazine is an antihistamine drug for allergies but it is still antiemetic Trimethobenzamide inhibits the chemoreceptors' trigger zone that sends nerve impulses to the vomiting center Perphenazine Prochlorperazine (Compro) Trimethobenzamide (Tigan)

Combination Drugs

This combination drug contains a neurokinin-1-receptor antagonist (fosnetuitant) and a serotonin 5-HT₃ receptor blocker (palonosetron). This drug used to treat nausea and vomiting from chemotherapy drugs is Akynzeo

Lower Gastrointestinal System

Located in the abdominal cavity and consists of the small intestine (duodenum, jejunum, ileum) and large intestine (cecum, colon, rectum, and anus) Digestive enzymes from gallbladder and pancreas flow into the duodenum through ducts. Peristalsis slowly moves food through the small intestine during digestion Waste and water excreted in large intestine Diseases of the lower GI system are IBS, ulcerative colitis, IBD, diarrhea, constipation, flatulence, and hemorrhoids. Obesity Antidiarrheal Drugs, laxatives, antiflatulents, hemorrhoids, and obesity

Drugs for IBD

Chronic disease of the small intestine and large intestine, which includes abdominal cramps, diarrhea, blood in feces, fever, inflammation, damage to the intestinal mucosa, and ulcers. Crohn's disease affects the ileum and colon. There is thickening of the intestinal wall, inflammation, ulcers, and interspersed normal mucosa or regional enteritis. Ulcerative colitis affects the colon and rectum causing inflammation and ulcers Corticosteroid drugs, interleukin inhibitor drugs, selective adhesion-molecule inhibitor drugs, tumor necrosis factor-blocking drugs

Corticosteroid Drugs

Orally, rectally, by suppository, or IM Betamethason (Celestone) Budesonide (Entocort, Ortikos, Uceris) Cortisone Hydrocortisone (Colo, Cort, COrtec, COrtenema Methylprednisolone (Depo, Medrol, Solu-Medrol) Prednisolon (Orapred, Pediapred) Prednisone

Interleukin Inhibitor Drugs

Bind to substances of interleukin 12 and 23 in the intestine and prevent them from activating NK cells and TNF. This is a monoclonal antibody drug Ustekinumab (stelara)

Selective Adhesion Molecule Inhibitor Drug

Integrin antagonists or integrin inhibitors. Block integrin that would normally help leukocytes migrate and adhere to areas of intestinal inflammation. Because of differences in chemical structure, not all selective adhesion molecular inhibitors work. Natalizumab can treat Crohn's disease, but vedolizumab can treat both Crohn's and ulcerative colitis Natalizumab (Tysabri) Vedolizumab (ENtyvio)

Tumor Necrosis Factor Blocker Drugs

Bind and inactivate TNF and prevent it from causing inflammation. These are monoclonal antibody drugs. Only certolizumab can treat Crohn's disease GOlimumab is used for ulcerative colitis Adalimumab and infliximab can treat both Adalimumab (Hulio, Humira) Certolizumab (Cimzia) Golimumab (Simponi) Infliximab (Avsola, inflectra, remicade, renflexis)

Drugs for Ulcerative Colitis

5-ASA drugs, and Janus-associated Kinase Inhibitor Drugs

5-ASA Drugs

5-aminosalicylic acid decreases intestinal inflammation by blocking the production of prostaglandins. These drugs are given orally and act systemically Mesalamine can be given rectally as an enema or suppository that acts topically on the intestinal mucosa Balasalazide (colzal) Mesalamine (Apriso, Asacol, Delzicol, Lialda, Pentasa) Olsalazine (Dipentum) Sulfasalazine (Azulfinide)

Janus-Associated Kinase INhibitor Drugs

Restrict Janus-associated kinase enzymes that normally stimulate an immune response by NK cells and lymphocytes in the intestinal mucosa Tofacitinib (Xeljanz)

Drugs for IBS

Chronic disease of the colon that is characterized by irritability of the intestine. Symptoms include cramping, abdominal pain, bloating, excessive mucus secretion, and diarrhea alternating with constipation but no damage or inflammation. Symptoms for IBS are caused by food allergies, lactose intolerance, and emotional stress, but the exact cause is unknown. IBS is treated with anti-infective, antispasmodic, Chloride channel activator drugs; GC-C agonist drugs; opioid receptor agonist drugs; serotonin 5-HT₃ receptor blocker drugs; serotonin 5-HT₄ receptor agonist drugs; and sodium/NHE₃ inhibitor drugs

Anti-infective

Antibacterial drugs that bind to bacterial RNA and keep it from reproducing. This is used to treat IBS not associated with constipation. Rifaximin (Xifaxan)

Antispasmodic Drugs

The anticholinergic effect blocks acetylcholine in smooth muscles around intestines. Decreases peristalsis, cramping, spasms, and diarrhea. Dicyclomine

Chloride Channel Activator Drugs

Chloride channel activator drugs stimulate chloride channels in mucosa of intestinal wall which causes fluid to flow into intestines to soften stool Used to treat IBS associated with constipation (Lubiprostone (Amitiza))

GC-C Agonist Drugs

Binds to the enzyme guanylate cyclase-C and causes the secretion of chloride, bicarbonate, and fluid into the intestines. Treats IBS associated with constipation LInaclotide (Linzess) Plecanatide (Trulance)

Opioid Receptor Agonis

Stimulate opioid receptors in the intestine; it decreases pain and has a side effect of constipation and is used to treat drugs associated with diarrhea Eluxadoline (Viberzi)

Serotonin 5-HT3 Receptor Blocker Drugs

Selectively block only 5 HT₃ receptors that act as ion channels on nerves around intestines. Activation of these receptors and ion channels normally causes pain, increased intestinal sections and peristalsis Blocking it decreases these things. This drug is used to treat diarrhea and IBS. Alosetron (Lotronex)

Serotonin 5-HT4 Receptor Agonist Drugs

Selectively stimulate only the 5-HT4 receptors on nerves around the intestines. This increases intestinal secretions and peristalsis. This is used to treat IBS associated with constipation Tegaserod (Zelnorm)

Sodium/NHE3 Inhibitor Drugs

Inhibit the exchange of sodium and hydrogen ions in the intestines This increases intestinal secretions and peristalsis while decreasing intestinal hypersensitivity. These drugs rae used to treat IBS associated with constipation Tenapanor (Ibsrela)

Other Drugs

Amitriptyline Rifaximin (Xifaxan)

Combination Drugs

Contains antispasmodic/anticholinergic (atropine, clidinium, hyoscyamine, scopolamine) and an antianxiety drug (chlordiazepoxide) or barbiturate sedative drug (phenobarbital) Donnatal (Atropine, hyoscyamine, scopolamine, and phenobarbital) Librax (clidinium, chlordiazepoxide

Antidiarrheal Drugs

Therapeutic effect by slowing peristalsis or absorbing extra extra water and secretions from intestine back into blood Used to treat diarrhea associated with bacterial infections, inflammatory bowel disease, IBS, and cancer Antidiarrheal drugs include anticholinergic drugs, anti-infective drugs, chloride channel regulator drugs, opiods

Anticholinergic Drugs

Block the action of acetylcholine, decreasing rate of peristalsis in the intestine Loperamide (Imodium A-D)

Anti-Infective Drugs

Are used to treat diarrhea associated with bacterial or protozoal infections (traveler's diarrhea, infectious diarrhea) Ciprofloxacin is an antibiotic for infection used to treat infection diarrhea Bismuth (Decrom, Kaopectate, Pepto bismol) Ciprofloxacin (Cipro) Nitazoxanide (Alinia) Rifamycin (Aemcolo)

Chloride Channel Regulator Drugs

Regulate the flow of calcium ions through calcium channels in the intestinal mucosa. Decreases intestinal secretions and fluid loss. Crofelemer is for diarrhea caused by retrovirus HIV Crofelemer (Mytesi)

Opioid Drugs

Opioid drugs treat moderate to severe pain but have a side effect of constipation that is therapeutic in treating diarrhea. Paregoric slows down peristalsis and decreases intestinal secretion. Intestinal secretion. It is a schedule III drug.

Combination Drugs

Contain an anticholinergic drug (atropine) and an schedule IV or V opioid drug (difenoxin, diphenoxylate) Lomotil (Atropine, diphnoxylate) Motofen (Atropine, diphenoxylate)

Antiflatulent Drugs

Used to prevent or treat intestinal gas. Alpha-D-galactosidase helps digest carbohydrates in gas-forming foods like beans. Lactase helps digest the lactose in milk that causes intentional gas in people who have LI, and simethicone decreases the surface tension of gas bubbles to prevent the formation of large areas of gas in the intestine Alpha-D-galactosidase (Beano) Lactase (lactaid) Simethicone (Gas-X, phazyme)

Laxative Drugs

Used for short-term treatment of constipation in conjunction with increased water and fiber intake and exercise. Patients who take opioids are at risk of developing constipation Drugs for constipation include bulk-forming laxatives, chloride, channel activator laxatives, GC-C agonist laxative drugs, irritant stimulant/laxative drugs, lubricant laxative drugs, opioid antagonist laxative drugs, osmotic laxative drugs, serotonin 5-HT receptor agonist laxative drugs, and stool softener laxative drugs Bulk-Forming Laxative Drug Contains indigestible dietary fiber and other substances that absorb and hold water in the intestines to create bulkier stool that stimulates peristalsis Calcium Polycarbophil (Equalactine, fibercon) Methyl (Citrucel) Psyllium (Cetamucil) Wheat Dextrin (Benefiber)

Chloride Channel Activator Laxative Drugs

Chloride channel activator drugs stimulate chloride channels in the mucosa of intestinal wall and causes fluid to flow into intestines and soften stool Lubiprostone (Amitiza)

GC-C Agonist Laxative Drugs

GC-C agonist drugs bind to guanylate cyclase-C and causes secretion of chloride, bicarbonate and fluids into the intestine to soften stool Linaclotide (LInzess) Plecanatide (trulance)

Irritant/Stimulant Drug

Act on smooth muscle to stimulate peristalsis. Cathartic Drug Bisacodyl (Correctol, Dulcolax, Ex-lax ultra, feen-A-Mint) Sennoside (per diem overnight relief, senokot)

Lubricant Laxative Drugs

Introduce extra oil or water to soften stool, increase bulk, and improve peristalsis. Castor oil and mineral oil are administered orally or rectally as an enema. Saline is administered as an enema. Castor oil Mineral oil (Fleet mineral oil) Saline (Fleet)

Opioid Antagonist Laxative Drugs

Opioid antagonist drugs are used to treat patients who are taking opioid drugs for relief of sever, chronic pain They cause constipation. Opioid antagonist laxative drugs only block opioid receptors in the intestine and do not cross the blood-brain barrier so they do not block the pain-relieving effect in other parts of the body Methylnatrexone (Relistor) Naldemidine (Symproic) Naloxegol (Movantik)

Osmotic Laxative Drugs

Use osmosis and osmotic pressure to attract water from blood into intestines to soften them; they are given orally except for glycerally, which is a suppository Glycerine Lactilol (Pizensy) Lactulose (COnstulose, Enulose) Magnesium Hydroxide (Milk of Magnesia, Pedia-lax) Polyethylene Glycol (MiraLax)

Serotonin 5-HT4 Receptor Agonist Drugs

Serotonin (5-HT) neurotransmitter. The 5-HT4 receptors are in the intestines. The laxative stimulates those receptors and increases intestinal secretions and peristalsis. They have a side affect of suicidal thoughts and behavior Prucalopride (Motegrity)

Stool Softener Drug

Emulsifiers that allow fat in the stool to mix with fluid in the intstine to soften stool Docusate (Colace, Dulcolax, Surfak)

Combination Drugs

Combination of sennosides and docusate Peri-colace (sennosides, docusate) Senokot-S (Sennosides, docusate)

Drugs for Hemorrhoids

Swollen protruding veins from the rectum or on the skin around the anus caused by increased intra-abdominal pressure during pregnancy or from straining to pass feces. They are easily irritated and can bleed Topical drugs include Corticosteroid drug (Hydrocortisone) Anesthetic Drugs (lidocaine, pramipexole) Astringent Drug (Witch hazel)

Drugs for Obesity

Suppress appetite or keep dietary fats from being absorbed from intestines into blood Drugs for obesity include anorexiant drugs, GLP-1 agonist drugs, Lipase inhibitor drugs Melanocortin receptor agonist drugs

Anorexiant Drugs

Appetite suppressant drugs, similar to amphetamines but with lower addiction. Suppress appetite by stimulating dopamine, norepinephrine or serotonin receptors in the satiety center of brain and causes sensation of satiety and fullness Short-term treatment of obesity because they are schedule II and schedule IV drugs Benzphetamine Diethylpropion Phendimetrazine Phentermine (Adipex-P, Lomaira)

GLP-1 Receptor Agonist Drugs

Slowly empty the stomach to give a sense of fullness and also activate receptors for GLP1, the appetite regulator in the brain. Both of these actions decrease food intake The drugs also decrease insulin secretion from the pancreas, so less glucose is metabolized. These are injected SubQ Liraglutide (saxenda) Semaglutide (Wegovy)

Lipase Inhibitor Drugs

Binds to lipase and inhibits its action so that it cannot break down dietary fats in the small intestine and instead allows them to be excreted rather than absorbed. These drugs are given orally. Orlistat (Alli, Xenical)

Accessory Organs of the GI System

The liver, gallbladder, and pancreas are accessory organs of the GI system. They contribute to digestion, even though food does not actually pass through them Diseases that affect accessory organs include hepatitis, cholelithiasis, cholecystitis, pancreatitis

Drugs for Hepatitis

The liver is a large, dark red-brown organ located in the right upper quadrant of the abdominal cavity. Liver cells produce bile stored in the gallbladder and then released into the duodenum in the presence of fatty food. The liver is used to metabolise drugs Diseases of the liver include hepatitis, an infection of the liver caused by a virus. There are four types of viral hepatitis: Hep A, Hep B, Hep C, Hep D Drugs to Prevent Hepatitis A and B Hepatitis A and B can be prevented with vaccination prior to exposure to the virus Hepatitis A vaccine (Havrix, vaqta) Hepatitis Vaccines (Engerix-B, Heplisav-B, Recombivax HB) Twinrix (Both Hep A and Hep B)

Drugs for Both Hepatitis B and Hepatitis C

Hepatitis B immune globulin can be given to a person who has been exposed to blood that possibly contains the hep B virus Chronic infections with Hep B and C are treated with interferon drugs NS3/4A, NS5A, or NS5B inhibitor drugs; nucleoside rever transcriptase inhibitor drugs; and nucleotide reverse transcriptase inhibitor drugs

Interferon Drugs

Antiviral and immune system-regulating effect. Slows the reproduction of hepatitis and stimulates the immune response to attack Interferon alfa-2b (Intron A) Interferon alfa-2a (pegasys)

NS3/4A, NS5A, and NS5B Inhibitor Drugs

Restrict protease, which is used to make protein in viral RNA, or polymerase, which is an RNA chain terminator in viral hepatitis Declatasvir Simeprevir

Nucleoside Reverse Transcriptase Inhibitor Drug

Restrict viral enzyme reverse transcriptase as it builds a new strand of viral RNA Entecavir (Baraclude) Iamivudine (Epivir) Ribavirin Telbivudine

Nucleotide Reverse Transcriptase Inhibitor Drugs

Restrict the enzymes that convert transcriptase in the hepatitis virus. The nucleotide has an additional molecule, which changes their MOA Adeforvir (Hepsera) Tenofovir (Vemlidy, Viread)

Combination Drugs

Chronic hepatitis C is also treated with these combination drugs that inhibit virus RNA fragments and protein synthesis. Contain two to up to four Ns3/4A, Ns5A, and NS5B inhibitor drugs for effective treatment (dasabuvir, elvasvir, glecaprevir, grazoprevir, ledipasvir, ombitasvir, paritaprevir, pibrentasvir, ritonvir, sofosburvir, velpatasvir, voxilaprevir) Epclusa (Sofosbuvir, Velpatasvir) Harvoni (Sofosbuvir, ledipasvir). Potentially able to treat and cure hepatitis C but can reactivated hepatitis B Mavyret (Glecaprevir, pibrentasvir) Viekira (dasabuvir, ombitasvir, paritaprevir, ritonavir) Vosevi (Sofosbuvir, velpatasvir, voxilaprevir) Zepatier (elbasvir, grazoprevir)

Drugs for Cholelithiasis and Cholecystitis

Gallbladder is located behind the liver. It concentrates and stores bile that is produced by the liver. Fatty foods in the duodenum cause the gallbladder to contract and release bile into the duodenum. Cholelithiasis is the presence of gallstones. It can form when bile is too concentrated with cholesterol that forms crystals into small and large gallstones. When the gallbladder contracts, the gallstones cause cramping Cholecystitis is the inflammation of the gallbladder that occurs when a gallstone blocks the cystic duct that leads to the duodenum. Initial treatment is lifestyle changes to avoid fats in the diet.

Bile Acid Drugs

Decrease the liver’s production of cholesterol, which decreases the presence of excess cholesterol and formation of stones. Chenodiol (Chenodal) Ursodiol (Actigall, Urso Forte)

Antispasmodic Drugs

Anticholinergic drugs that block the action of acetylcholine in the smooth muscles around the gallbladder to relieve contractions, spasms, and colic. Hyoscyamine (Anaspaz, Levbid, Levsin, Symax)

Drugs for Pancreatic Insufficiency

The pancreas is an exocrine gland of the GI system. It secreted digestive enzymes into the duodenum. Pancreatic enzymes Trypsin and chymotrypsin are proteases that digest proteins, amylase digests, carbohydrates, and lipase digests fats Patients with pancreatitis or those who had their pancreas removed have insufficient levels of enzymes. These drugs are used to treat patients with cystic fibrosis. The drug contains amylase, lipase, and protease combined into one drug. Pancrelipase (Creon, prancreaze, pertzye, viokace, zenpep) The pancreas also secretes insulin. Hyposecretion of insulin from the pancreas causes diabetes melli