Final Flashcards
What are two common causes of acute cholecystitis?
Gallstones and Obstruction
What percentage of the population in the US can become chronic cholecystitis patients?
10-20%
In cholecystitis patients, most gallstones are made of what?
Cholesterol
5 types of Liver diseases
Fatty Liver Hepatitis Biliary Disease Metabolic disease Vascular
What can liver diseases lead to?
Cirrhosis
What is fatty liver caused by?
ETHOH, obesity and diabetes Mel.
What is hepatitis caused by?
virus, drug or autoimmune
What three things is the liver made of?
hepatocytes, duct cells and blood vessels
What does all the metabolic work of the liver?
Hepatocytes
What three things does the portal tract contain?
Bile ducts, portal veins, hepatic artery
What is the #1 cause of liver toxicity?
Drugs
What happens if hepatocytes die in large sheets?
the areas fill up with blood. Blood can build up due to heart failure and backflow
What happens if cannuliculi in liver fill with bile due to cholestasis?
Jaundice
Why do dentists need to be careful with Hepatitis patients?
If caused by viruses, it can be contagious
What is Hepatitis?
Inflammation of the liver
Acute hepatitis is cause by which two viruses?
A and E
Which kind of hepatitis can resolve itself?
Acute
Which hep viruses start acute and frequently progress to chronic and can lead to cirrhosis and even hepatocellular carcinoma?
B and C
Acute hepatitis lasts for less than:
6 months
(T or F) There is fibrosis in acute hepatitis patients
False
Hepatitis C is commonly transmitted by:
Blood and Needles
(T or F) In hep c, there are rarely symptoms in the acute stages
True
Which Hepatitis virus is more common in China, less common in the United States?
C
Are there immunizations available for Hepatitis C?
No
What is the most effective treatment for Hep C?
combination of antivirals (usually including ribavirin)
How is Hep B transmitted?
Blood and Needles
(T or F) Heb B rarely becomes chronic
False
What percentage of the population is infected with Hepatitis B?
2-10%
Hep C virus is found in how many carriers worldwide?
> 170 Million
What percentage of hepatocellular carcinoma are associated with Hep. B viral infections?
Half
What is Cirrhosis?
regenerative hepatocyte nodules; fibrosis surrounding nodules
Who is autoimmune hepatitis typically found in?
obese middle-aged females
Autoimmune hepatitis typically responds well to:
Steroids
In fatty liver patients, what color does the liver turn?
Yellow
What is steatosis?
fat accumulation in the liver that is temporary, with no cellular damage
What is steatohepatitis?
damage to the liver with fibrosis present (chronic)
What is Metabolic disease often associated with?
Iron overloads
What causes Wilson’s disease?
copper metabolic defect goes to hepatitis then cirrhosis
What is Biliary disease?
Destruction of bile ducts, bile backs up into the liver and causes inflammatory cells to surround ducts—may form granulomas
Why at very high blood concentrations normal kinetic properties of a drug or toxin can change?
metabolism and protein binding become saturated and elimination become a zero order pattern
How the apparent volume of distribution for drug or toxin determine the effectiveness of hemodialysis at purifying them from the blood?
a large Vd implies a substance will not be easily accessible to purification attempts.
What is the difference between bioaccumulation and biomagnification?
- bioaccumulation: accumulation of a toxic agent when administration of the drug exceeds the body’s ability to metabolize and elimination
- biomagnification: increases of toxin in a biological system as it passes up the food chain.
What defines some metals as “heavy”?
naturally occurring elements with high atomic weight and a density 5-times greater than water.
What are the most toxic substances?
lead (#1), mercury (#2) and arsenic (#3)
Heavy metals interfere with normal biological processes how?
By competing with normal substrates
The shorter the t1/2 the (more/ less) effective is the use of chelators to remove the heavy metal
More
What are the primary exposure sources of lead?
building materials/construction, batteries, lead pipes, paint
Why is lead exposure particularly detrimental to young children?
They often eat or suck on things that contain lead, such as things covered with lead paint, dirt etc.
What substance in a child’s body does lead compete with?
Their bodies absorb because lead competes with CALCIUM, and growing bodies require considerable Ca.
What percentage of lead does a child absorb as opposed to an adult?
Children absorb >50% consumed whereas adults absorb ~10-15%
What are the toxicokinetics of lead?
t1/2 = 1-2 months
Symptomology of lead?
Headaches, neurocognitive deficits, kidney damage
What is the main repository in the body for its lead burden?
It substitutes for Ca++ in bone
What are Burtonian lines?
Lead lines causing a darkening of the gingiva
What two things can lead cause in the body?
Anemia, immunosupression
What is the most sensitive target organ for lead poisoning?
The developing CNS-can lead to encephalopathy
What can lead cross in the body?
BBB and concentrates in gray matter, can cross placenta
What is the treatment regimen for lead toxicity, particularly the recommended chelators?
Remove exposure
Administer a chelator such as EDTA (edetate calcium disodium). It removes Pb from bone slowly and requires multiple chelating treatments
(T or F) Mercury is solid at room temperature
False
What is the primary form of mercury used?
methylHg form
What are the primary exposure sources of mercury?
Found in fish
Amalgam (no CDC-recognized evidence that it is a problem in dentistry)
thermometers
What is the mechanism of mercury toxicity?
Reacts with selenium (necessary for reducing oxidized Vitamin C and E)
Can cause gingivostomatitis
Inhibits enzymes
Acute tubular necrosis
What do we know about mercury symptomology?
Can cause neurological, psychiatric problems
What were the CDC’s conclusions regarding mercury exposure related to (a) thimerosal in influenza vaccines and (b) dental amalgam?
No convincing evidence that quantities of mercury from either source is significantly high to cause problems.
What is the treatment regimen for mercury toxicity, particularly the recommended chelators?
Dimercaprol (can only use acutely), succimer
Why is dimercaprol contraindicated in chronic mercury intoxication scenarios?
Chronic use of dimercaprol can cause serious renal toxicity
What are the primary exposure sources of arsenic?
industrial contamination
groundwater contamination
What do we know about the toxicokinetics of arsenic?
- absorbed through respiratory mucosa and GI tract, but not so much through the skin
- excreted primarily through the kidney
What do we know about the symptomology of arsenic?
Fatigue, anemia, renal failure, hyperpigmentation
Peripheral neuropathy
Carcinogenic in lungs, skin and bladder
Hemolytic on RBC
What is the mechanism of arsenic toxicity?
Increases ROS (reactive oxygen species) Binds to sulfhydryl groups in keratinized tissue, where it is acts as a depot Inhibits enzymes Hemolytic action on RBCs Can be carcinogenic on lung and skin.
How does the treatment regimen, including the use of chelators (e.g., Unithiol or dimercaprol), differ for acute or chronic arsenic intoxication?
Chelators are useful for acute, but not chronic
How do chelators work on heavy metals?
They render heavy metal ions unavailable for covalent interactions
How does the half-life of the heavy metal affect the ability of a chelator to remove it from a target organ?
The longer the t1/2, the less effective is the chelator
Is it better to treat with chelators quickly or take a wait and see approach when an exposure has occurred?
Usually most effective when treated ASAP
What is FDA-approved for use as monotherapy in heavy metal poisonings?
Dimercaprol
Why should dimercaprol not be given as a monotherapy after chronic exposure to lead?
It pulls Pb from bone and it goes to brain and causes toxicity
How does dimercaprol’s therapeutic index compare to succimer or unithiol?
It can be very toxic, especially on kidneys—succimer has for most part replaced dimercaprol
What is Succimer?
water-soluble form of dimercaprol
What is succimer’s main mechanism for removing heavy metals?
Binds to cysteine to form mixed disulfides which are excreted
What is the half-life of succimer?
2-4 hours
What is succimer’s only route of administration?
Oral
Which is safer, succimer or dimercaprol?
Succimer
Edetate Calcium Disodium (CaNa2-EDTA) is FDA-approved for which heavy metal poisonings ?
Lead
Does CaNa2-EDTA target intracellular or extracellular lead?
Extracellular
What is only route of administration?
IV
What is ‘s half life?
1 Hour
How is CaNa2-EDTA excreted?
100% by the kidneys
In which patient population is CaNa2-EDTA contraindicated?
anuric patients
Unithiol is a water soluble derivative of what other chelator?
Dimercaprol
What are the routes of administration for unithiol?
Orally or i.v.
Half life of unithiol?
20 hours
Is unithiol FDA approved for treatment of heavy metal poisonings?
No
Pure Food and Drug Act
caused by addiction to opium and cocaine; requires labeling, patent medicines
Modified Food, Drug and Cosmetic Act
required safety; caused by diethyleneglycol tragedy
Durham-Humphrey Amendment
Rx vs. OTC
Kefauver-Harris Amendment
phocomelia caused by thalidomide tragedy; requires safety and efficacy
Dietary Supplement Health and Education Act
regulates herbal products; defines herbal products as “foods”
What is the distinction between prescription and OTC drugs?
Addiction/abuse liability
Relative safety
Intent of use-does it require professional input/control
What things does the FDA regulate?
Foods, dietary supplements, bottled water, food additives, drugs, biologics, medical devices, cosmetics, veterinary products, tobacco products, advertising of these products.
What are the phases of drug testing?
Animal preclinical testing: controlled by IACUC (institutional animal care committee)
Phase I: small group of healthy (usually) subjects to test safety, doses, administration and other kinetics
Phase II: small group of subjects with condition to be treated to test safety (still) and efficacy
Phase III: extended clinical phase- large group of subjects, using double blind construct, placebos and multi-sites groups to test for statistical efficacy
Marketing (‘phase 4’): see how the product does in production
What are the non-prescription drug categories?
I (safe and effective), II (unsafe or ineffective), III (not sure—requires more studies)
Three types of decongestants
Oxymetazoline
Phenylephrine
Pseudophedrine (restricted sales)
What is the difference between systemic and topical decongestants?
systemic (increase BP, but longer acting decongestant) vs. topical (less systemic problems, but more likely to cause dependence-tolerance; shorter acting but more effective as decongestant).
3 types of antihistamines
- Diphenhydramine (drowsiness)
- Chlorpheniramine (Chlor-Trimeton)
- Loratidine (Claritin) less drowsiness
3 types of Antitussives
- Codeine
- Diphenhydramine
- Dextromethorphan
What is a common expectorant?
Guaifenesin
What are Demulcents?
cough drops/syrupy products; coat the throat to reduce irritation
What is the benefit of Water/humidification?
decrease viscosity of respiratory secretions
Do Antivirals benefit colds?
shortens infection for 1-2 d if taken early
3 common antivirals
- Oseltamivir (Tamiflu-not OTC)
- Zanamivir (Relenza-not OTC)
- Docosanol (Abreva)- cold sores (Herpes)-antiviral
4 Analgesics
- Aspirin
- Acetaminophen
- Ibuprofen
- Naproxen
What is used to treat cold sores?
Docosanol
What is Phenol?
Oral Anesthetic
What are the side effects of nicotine?
dizziness, headaches, nausea
What is an antifungal used for vaginal infections?
Miconazole
What are Diphenhydramine and Doxylamine?
antihistamine, sleep aid
What is a first said antibiotic, preventive on minor abrasions
Neosporin/Polysporin
What is hydrocortisone used for?
(anti-inflammatory, anti-itching) dermal lesions, eczema, insect bites, poison ivy
What is Capsaicin?
(pain-relief); topical ointment, TRPV channels
Name 2 anticholinergics, used for motion sickness
Scopolamine, Dimenhydrinate
What are some side effects of Dimenhydrinate?
dry mouth, constipation, difficulty, blurred vision, reduced urinating
What is Minoxidil for?
hair growth
Herbal Products (can/ cannot) be promoted to diagnose, cure or prevent disease
Cannot
St. John’s Wort
Promoted to treat depression
Echinacea
Promoted to treat colds, although controversial
Aloe Vera
Promoted for skin care-help with wound healing
Dietary supplement to treat constipation
Cranberry
Used to prevent urinary tract infection
Garlic
Slowly lowers cholesterol (minor effect)
Some thinning of blood
Ginko
Promoted to improve memory
Can increase bleeding risk
Ginseng
Boost immune system
May lower blood sugar
Ephedra
Sympathomimetic: contains ephedrine
Used for anorexia and stimulant effects
FDA require removal from most OTC products, although still will occasional seen in an herbal preparations