The major classes of drugs include antacids (purchased otc, including Tums, Maalox, Mylantin, etc.), anti-diarrheal drugs, histamine H2 receptor antagonists, laxatives, prokinetic agents, proton pump inhibitors (PPIs), protectants, antiemetic agents, and anticholinergic agents.
When we talk about peptic ulcers, the saying used to be “no acid, no ulcer” and that is still so, but we need to consider the role of Helicobacter pylori infection. We can eradicate H. pylori and cure ulcers, not just manage the symptoms. This is very important, most pts who present to an MD with dyspepsia or chronic heartburn will be worked up to test for the presence of these bacteria as a causative agent.

When you’re looking at an H. pylori infection, you want to inhibit the HCl so the PPIs are the best. The H2 antagonists were displaced because of the potency of the PPIs. Initially bismuth ion was introduced as a colloidal, and it didn’t help irradicate H. pylori. Flagyl was tried as a regiment against H. pylori, but wasn’t good. The most common antibiotic now used with a PPI is Clarithromycin, although the original protocols indicated amoxicillin or tetracycline. Some Kaiser physicians don’t have the luxury of writing a combination prescription, so will prescribe one or two drugs along with a PPI. Today though, many of the companies combine an antibiotic with a PPI in a so-called pack – I think the best selling regimen is called Z-pack, which is azithromycin plus a PPI.

The agents capable of promoting appropriate GI motility, particularly in GERD are called prokinetic, they cause the stomach contents to be pushed towards the intestine rather than be pushed up towards the esophagus. So the prokinetic drugs are almost exclusively used for the treatment of GERD. The agent can be a muscarinic agonist, but obviously that would cause all the cholinergic side effects. The anticholinesterase would have the same systemic side effects. The dopamine inhibitors (Reglan is a specific drug of this class) are very important, we’ll come back to them. Cisapride (a 5-HT agonist) has been withdrawn for deaths, there was discovered to be some drug interactions.

When you look at agents capable of treating diarrhea, in Europe opiate derivatives are popular treatments. They increase resistance to flow and decrease propulsion. Bismuth subsalicylate (Pepto-Bismol) can be used for diarrhea, it’s a local acting drug and can be purchased otc, but doesn’t have the power of the opiates. Pure anti-cholinergic drugs, including atropine, reduce contractile activity. There are also gel-forming adsorbants (Kaopectate). Remember, diarrhea can be a serious symptom of a very profound infection of the GI tract. Cholestyramine, an ion-exchange resin, is used as an adjunct in lowering cholesterol. It is also sometimes used in the tx of diarrhea, but not as common as the other classes.

Nocturnal gastric acid reflux results in significant acidic gastric fluid entering the oral cavity. Patients complain of a bitter, acid taste in their mouth. Chronically, this acidic environment results in significant enamel erosion and rampant caries.
Pharmacological Mgt of GERD:
acid suppression (best: proton pump inhibitors) alter gastric-esophageal dynamics (e.g., metoclopramide [Reglan]) increase esophageal peristalsis increase esophageal sphincter tone promote gastric emptying antacids mask the symptoms of dyspepsia

Indications for Lansprazole and Omeprazole (PPIs)
Heartburn and GERD symptoms; erosive esophagitis, maintenance of healed erosive esophagitis, H. pylori eradication to reduce the risk of duodenal ulcer recurrence (combo tx includes Prevacid [PPI], Amoxicillin [penicillin derivative], and Biaxin [a macrolide antibiotic]); active and maintenance of healed duodenal ulcers; active benign gastric ulcers; hypersecretory conditions including Zollinger-Ellison Syndrome.
H. pylori Treatment (FDA approved, 1996)
First 2 weeks: Omeprazole (40 mg/day) & Clarithromycin (500 mg/day)
Days 15-28: Omeprazole (20 mg/day)
74-83% eradication achieved!

(to treat hypermotility and gut spasms, may not be associated with diarrhea)
Atropine; Scopolamine; Hyoscyamine (Levsin); Loperamide (Imodium); Opoiates; Combination Products.
Donnatal: Atropine, scopolamine, hyoscyamine
Lotmotil: Diphenoxylate (opiate derivative) and atropine

Myasthenia gravis: muscle weakness due to autoimmune disease affecting the neuromuscular transmission mechanism (use anticholinesterases= oral manifestations) Spasticity of Cerebral Palsy: usually dental care is performed in a hospital (use dantrolene, baclofen) Congenital Myotonia: sarcolemma membrane is excitable and depolarizes causing contraction of muscles (rare) (Hyperexcitable sarcolemal membrane) Tetany: hypocalcemia, muscle goes into contractions (best tx is to correct electrolytes: give Ca++ through diet or i.v. if an emergency) Laryngospasm: very rare but frightening, various causes including the use of ACE inhibitors (emergency use: neuromuscular blocker: very last resort, must be trained as an anesthesiologist to use this) Muscle rigidity in Malignant Hyperthermia: rare, precipitated by general anesthetics (use dantrolene) Muscle spasm of unknown origin: stiff neck, low back pain, etc.; low back pain is the 2nd most common reason to see an MD (#1 is sinusitis) (use diazepam, carisoprodol, cyclobenzapine) Flacid Paralysis: polio, multiple sclerosis (experimental tx: snake venom, exotic but with the advent of worldwide polio vaccine, polio is pretty much a non-issue) Torticollis: head turned violently, pt cant straighten out (cause unknown)

Acute Muscle contusion-sprain
(physical therapy; cold packs; alternate with heat)
These drugs have different sites of action
Dantrolene: acts directly on skeletal muscle to prevent the release calcium from the sarcoplasmic reticulum and thus prevent contraction; it is fairly specific for skeletal muscle
Diazepam: variety of pharmacological features, can act on specific receptors to inhibit the reflex mediated through the spinal cord that mediates motor impulses to the skeletal muscles.
Baclofen: acts on a specific GABA receptor as an agonist.

Diazepam (Valium): long acting benzodiazepam. No other drug is indicated for nocturnal bruxism.
Action: acts to inhibit gamma motor neuron activity at spinal level, reducing reflex spasm.
Uses: adjunct in relief of skeletal muscle spasm due to reflex spasm associated with muscle inflammation secondary to trauma; spasticity caused by upper motor neuron disorders such as cerebral palsy, spinal cord injury; athetosis; stiff-man syndrome; refractory low-back pain
Dental Use: management of severe nocturnal bruxism; muscle relaxing properties (and anxiolytic action).

GABA B receptor AGONIST (Diazepam is an antagonist/inhibitor).
Action: CNS acting skeletal muscle relaxant. Depresses monosynaptic-polysynaptic afferent reflex activity at spinal cord level. Relieves spasm caused by upper motor neuron lesion. Effective p.o. (orally).
Uses: multiple sclerosis related spasm. Treat trigeminal neuralgia (tics= facial muscles contracting which effect the quality of life, sleep, etc.; usually in the realm of a neurologist rather than a dentist). Not an analgesic.
Side effects: Transient drowsiness, vertigo, fatique, ataxia (movement disorder), confusion, hypotension.

Action: acts within CNS at brainstem level. Net effect is reduction of tonic somatic motor activity influencing motor neurons to muscle. Less firing of alpha motor neurons; does not paralyze muscles, only relieves spasm. These drugs (including Diazepam and Baclofen) are NOT skeletal muscle blocking drugs.
Use: to relieve skeletal muscle spasm of local origin. Does not paralyze muscle. Effective orally.
Precautions: because of atropine-like side effects, should be used with caution in patients with urinary retention, glaucoma (increased intraocular pressure)… glaucoma can be exacerbated by any anticholinergic drug.

Mechanism of Action: interferes with release of calcium ion from the sarcoplasmic reticulum of skeletal muscle.
Indications: Treat muscle spasticity resulting from upper motor neuron disorders (eg, spinal cord injury, stroke, cerebral palsy, multiple sclerosis.) Treat spasm associated with malignant hyperthermia (anesthetic caused). It is NOT indicated for skeletal muscle spasm of local origin such as arthralgias.
Contratindications: active hepatic disease (eg, hepatitis, cirrhosis)
Warnings: risk of severe hepatic disorders including fatalities. Monitor liver function (SGOT, SGPT, alkaline phosphatases). Discontinue drug at signs of hepatic injury.

Action: inhibits release of Acetylcholine at neuromuscular junction. Purified botulinum toxin Type A produced from C. botulinum.
Uses: reduces excessive abnormal contraction associated with strabismus (crossed eyes) and blepharospasm (closure of upper eyelids). Long acting. Used for cosmetic surgery to combat wrinkles, injected locally around the eye.
Doses: amounts injected into muscles do not cause systemic effects (1.2-5.0 units per muscle).
Botox or Oculinum injections have no dental consequences to us. No systemic effects because they are injected locally only.

Actions: The mode of therapeutic action has not been clearly identified, but may be related to its analgesic properties. Orphenadrine also possesses anticholinergic actions.
Indications: management of pts who are also getting other modes of therapy for care of pain conditions associated with spasms.
*So the question arises: do we combat the pain to stop the spasm, or combat the spasm to stop the pain? An axiom of physical therapy says that if you stop the pain, spasm is blocked. So both mechanisms would work. Norflex is indicated specifically for pain associated with muscle spasms, and has no indications for other pain.

extremely rare, usually associated with anesthetic use and i.v. sedation. Not a smooth muscle phenomenon. Protective reflex to prevent substances from entering lower respiratory tract (bronchioles, lungs). Partial or complete adduction (closure toward midline) of vocal cords (voluntary/ skeletal muscle). Pt grasps throat; crowing sounds. With complete obstruction of airway, hypoxia, cyanosis (turns blue), cardiac death can occur.
Causes: irritation of vocal cords by blood, mucus, saliva, dental debris. Excessive parasympathetic activity (parasympathomimetics drugs). High concentrations of general anesthetics. This is one reason we use protective gauze barriers in extractions, to prevent blood and irritants from contacting the vocal cords; also we make sure the tongue is clear of the throat, and suction out the debris from the throat.

(a common condition called “essential tremor”, different from Parkinson tremor).
Propranolol (non-selective beta-1, beta-2 blocker): has a spasmolytic action on skeletal muscle. This is the drug of choice. The doses range from 160-320mg. At higher doses, the pt will get hypotension, bradycardia, depression, fatigue, impotence, headache, breathlessness.
Primidone: metabolized to a barbiturate, causes relaxation. Side effects: sedation, nausea, vomiting.
Gabapentin (Neurontin): approved for epilepsy, approved for neuralgias, also effective in skeletal muscle tremor. Never to be used as a first line agent, probably always as an adjunct because of its side effects: drowsiness, fatique, slurred speech, imbalance, nausea, dizziness.

Two kinds of pain:
• Visceral Pain: Deep, throbbing, delocalized pain, associated with the visceral organs.
• Somatic Pain: Sharp, piercing, pain localized to the abdominal wall.
Abdominal Medical History: (pqr)2st3
• P -- Provoking: What have you noticed that makes this pain worse?
• P -- Palliating: What relives the pain?
• Q -- Quantity: How much pain are you having?
• Q -- Quality: What does the pain feel like?

Boundaries of the Abdomen:
• Superior Boundary: The diaphragm. It extends to ICS-5 superiorly (at the median line; it is more inferior around the
edges).
o Hence the superior limit of the liver is also ICS5 since it push up into the diaphragm.
• Posterior Boundary: Lumbar Vertebrae, and Quadratus Lumborum and Transverse Abdominis muscles.
• Anterolateral Borders: The muscles of abdominal wall: transversus abdominis, and internal and external abdominal
oblique.

Inguinal Canal: Formed from the aponeuroses of the three flat muscles.
It a diagonal passage. Most tubular structures pass through membranes diagonally, as the ureters and fallopian tubes do.This provides reinforcement on the wall of the structure being entered.Contents of Inguinal Canal
o Spermatic Cord (male) or Round Ligament (female)
o Ilioinguinal Nerve
o Genital Branch of the Genitofemoral Nerve.
Inguinal Triangle (Hesselbach's Triangle): An area of weakness in the aponeurosis, where direct hernias can occur.

Spleen: It is actually mesodermal in origin, not endodermal like the rest of the abdominal organs.
Retroperitoneal Space: The area behind (posterior to) the peritoneum. Any organs not completely (or almost completely) covered by peritoneum are considered retroperitoneal organs.
Abdominal Cavity: Everything but the lateral, posterior, and anterior body walls of the abdomen, including both the peritoneal cavity and the retroperitoneal space.
Peritoneal Cavity: That part of the abdomen invaginated by peritoneum.
Peritoneum has visceral and parietal layers, just like the pleural cavity. It is analogous to the organs pushing themselves into the peritoneum, like a fist into a balloon.

Mesentery: Two layers of peritoneum opposing each other. Vessels and nerves often lie in the mesentery, where they can easily reach the organ where the peritoneal layers separate and reflect off the organs.
THE Mesentery: The one that connects the small intestine to the posterior abdominal wall.
The root of the mesentery is where the Mesentery connects to the posterior wall.Transverse Mesocolon: Specific mesentery connecting the transverse colon to the posterior peritoneum.Sigmoid Mesocolon: Specific mesentery connecting the sigmoid colon to the posterior peritoneum.The Anterior Surface of the Diaphragm:

FOREGUT:
STRUCTURES:Stomach1st two parts of the duodenum: Duodenal Cap and Descending Duodenum. Liver Gall Bladder Pancreas
ARTERIAL VASCULAR SUPPLYBranches of the Celiac Trunk
LYMPHATIC SUPPLYBranches of the Celiac Nodes
REFERRED PAIN: Occurs in the Epigastric Region.VENOUS RETURN: The portal vein.INNERVATION:Parasympathetic: From Vagus nerve (C10). It is perivascular -- it follows the blood vessels.Sympathetic: From the Greater Thoracic Splanchnic Nerves (T6-T10)------------------------------------------------------------------------------------------------
MIDGUT:
STRUCTURES:Third and fourth parts of duodenum: Horizontal and Ascending Duodenum.JejunumIleumCecumAscending ColonFirst 2/3 of Transverse Colon ARTERIAL VASCULAR SUPPLY Branches of the Superior Mesenteric Artery

DEVELOPMENT:
Stomach begins as a mere dilation of the primitive gut tube.It undergoes two basic processes: differentiation and rotation.Initially tube attaches to dorsal and ventral walls via dorsal and ventral mesenteries.Ventral Mesentery eventually becomes lesser omentum.Dorsal Mesentery (Dorsal Mesogastrium) eventually becomes greater omentum.
Rotation: Then the whole structure rotates 90 to the right, dragging the mesentery along with it. The dorsal mesentery becomes the left side of the body, and the posterior of the stomach becomes the left lateral aspect.Differential Growth: Then differential growth produces the fundus, the greater curvature, and the lesser curvature of the stomach.LOCATION: The pylorus of the stomach at the level of L1, in the transpyloric plane. Generally in the right epigastric region, but the location varies depending on position, weight, physiology, etc.EXTERNAL MORPHOLOGY:

DEVELOPMENT:
· Duodenum is the dividing point between the foregut and midgut.
· It forms in response to the rotation of the stomach.
LOCATION:
· It is retroperitoneal. (The first portion is actually intra - peritoneal, but we won’t count that).

DEVELOPMENT:
Starts out with a dorsal and ventral pancreatic bud on either side of the duodenum. The ventral bud rotates 180 and joins the dorsal bud. The stalk to the ventral bud becomes the major papilla The main pancreatic duct is formed from both dorsal and ventral buds. Annular Pancreas: The pancreatic lobes migrate around duodenum in the wrong direction and fuse with each other, strangling the duodenum. Can completely block or at best result in stenosis of duodenum.

DEVELOPMENT: Foregut closely associated with primitive cystic and pancreatic ducts.
Starts out as the hepatic diverticulum. Hepatic Duct elongates throughout development and joins with cystic duct to form common bile duct in the adult. The liver elongates into the septum transversum during development. It continues to grow into the diaphragm later, to create the bare area of the liver -- the part that has no peritoneum covering it. The omental foramen is a free border of the lesser omentum. The portal triad travels through this hole. The ventral mesentery in the embryo reduces to become the falciform ligament i the adult.

LOCATION: Located in the gallbladder fossa of the liver, on visceral (posterior side), medial-left lobe.
EXTERNAL MORPHOLOGY: A pear-shaped sac, containing concentrated gallbladder bile.
Small or large amount of mesentery surrounding sac. Composed of: Fundus Body Neck

DEVELOPMENT: Small intestine develops as a herniation into the umbilical region.
Bowel spins 90 counterclockwise during growth, so that the distal end is to the left of the proximal end. Then, in the Return Phase, there is a 180 rotation, which places the cecum just inferior, to the liver. Then the Cecum usually descends somewhat, but in some people and it doesn't, and is thus termed a sub hepatic cecum. Fixation occurs lastly: Organs become retroperitoneal secondarily. They start with peritoneum surrounding them, then they implant on the posterior wall, then they lose their peritoneum. At this point, what was once visceral peritoneum is now parietal. This secondary fixation occurs with all retroperitoneal organs except the rectum, which never has peritoneum in the first place.

DEVELOPMENT:
Cecum, Ascending Colon, and Proximal 2/3 of Transverse Colon are midgut. Distal 1/3 of Transverse Colon, Splenic Flexure, Sigmoid Colon, Rectum, and Proximal Anal Canal are hindgut. Cloacal Membrane: At the distal end of the hindgut in the embryo. Allantois: Posterior part of the yolk sac. It will become the Urogenital Sinus and primitive urogenital system. • Invasion of the Folds: Tourneaux's Fold: A wedge of mesoderm that invades the hindgut region along the midsagittal plane. At same time, lateral Rathke's Folds invade along the frontal plane. These two folds come together such that the hindgut is separated from the primitive urogenital sinus. Perineal Body: The tissue in between the two primitive tubes formed by the Rathke's and Tourneax's Folds. It will form the future urogenital region. The perineal body divides two tubes, which are: Anorectal Canal Urogenital Sinus: This will be future perineum of the adult -- the region below the abdomen and superior to the pelvic bones, medial to the thighs. Perineal body is the common attachment site for future muscles in the region: Anal Sphincter. Muscles associated with the pelvic and urogenital diaphragms. In females it provides the primary support for reproductive organs. Proctodeum: Distal portion of hindgut, still covered by cloacal membrane. The cloacal membrane will eventually perforate, resulting in the anal opening. Pectinate Line: The division of hindgut (endodermal) anal canal, and ectoderm from invagination of the skin. They are both supplied by different vessels, nerves, etc. Upper Anal Canal, superior to pectinate line, is endodermal hindgut. Lower Anal Canal, inferior to pectinate line, is ectoderm. The Pectinate Line can be identified by looking for the anal columns, longitudinal folds of mucosa that demarcate the upper anal canal. Collateral Circulation: Due to the pectinate line, there are two alternative circulations in the area. Caval System of vessels supplies the ectodermal lower anus: Rectal Veins ------> Iliac Veins ------> Caval System Portal System of vessels supplies the endodermal upper anus: Superior Rectal Veins ------> Inferior Mesenteric Vein ------> Portal Vein System Because of the anastomosis, if there is an occlusion in one system, blood can get back to the circulation via the collateral system.

Abdominal Aorta:
· Enters the Aortic Hiatus between the right crus and left crus of the diaphragm at the level of T12.
· Extends retroperitoneally along the anterior surface of the vertebrae (slightly to the left), until the level of L4.
· Bifurcation of the Abdominal Aorta: It bifurcates at L4, into the Left Common Iliac and Right Common Iliac Arteries.