Module 3

Question 1

What is the mechanism of action of penicillin?

Answer 1

• cell wall synthesis inhibitors ( damaging cell wall to allow water to enter and destroy the organism);
• bactericidal;
• mostly gram-positive bacteria.

Question 2

What is the mechanism of action of cephalosporins?

Answer 2

• similar to pencillins;
• cell wall synthesis inhibitors (damaging cell wall to allow water to enter and destroy the organism);
• bactericidal;
• mostly gram-negative bacteria; classified by 1st-5th generation drugs

Question 3

What is the mechanism of action of carbapenems?

Answer 3

• cell wall synthesis inhibitors ( damaging cell wall to allow water to enter and destroy the organism);
• bactericidal;
• the beta-lactam ring is very resistant to destruction by betalactamase.

Question 4

What are the drugs in the penicillin class?

Answer 4

Penicillin G & V

Question 5

What are the drugs in the cephalosporin class?

Answer 5

cefazolin (Ancef, Kefzol) cephalexin
(Keflex) (1st gens), cefixime (Suprax) (3rd gen), ceftaroline
(Teflaro), cefepime (Maxipime) (4th and 5th gens)

Question 6

What drugs are in the beta-lactam antibiotic class?

Answer 6

penicillin, cephalosporin, monobactams, carbapenems; bactericidal

Question 7

Describe the characteristics of the 1st gen cephalosporin.

Answer 7

First-generation cephalosporins are the most effective drugs in this class against gram-positive organisms including staphylococci and streptococci. They are sometimes drugs of choice for these organisms. Bacteria that produce beta-lactamase will usually be resistant to these drugs.

Question 8

Describe the characteristics of the 2nd gen cephalosporins.

Answer 8

Second-generation cephalosporins are more potent, are more resistant to beta-lactamase, and exhibit a broader spectrum against gram-negative organisms than the first-generation drugs. The second generation agents have largely been replaced by third-generation cephalosporins.

Question 9

Describe the characteristics of the 3rd gen cephalosporins.

Answer 9

Third-generation cephalosporins exhibit an even broader spectrum against gram-negative bacteria than the second-generation drugs.
They generally have a longer duration of action and are resistant to beta-lactamase.
These cephalosporins are sometimes drugs of choice against infections by Pseudomonas, Klebsiella, Neisseria, Salmonella, Proteus, and H. influenza.

Question 10

Describe the characteristics of 4th and 5th gen cephalosporins.

Answer 10

Fourth- and fifth-generation cephalosporins are effective against organisms that have developed resistance to earlier cephalosporins.
Fourth-generation agents such as cefepime (Maxipime) are capable of entering the cerebrospinal fluid (CSF) to treat CNS infections.
The fifth-generation drugs such as ceftaroline (Teflaro) are designed to be effective against MRSA infections.

Question 11

What example of drugs are the carbapenems?

Answer 11

Imipenem (Primaxin), ertapenem (Invanz), doripenem (Doribax), and meropenem (Merrem IV)

Question 12

What is the mechanism of action of fluoroquinolones?

Answer 12

DNA synthesis inhibitors inhibiting two bacterial enzymes DNA gyrase and topoisomerase IV affecting replication and DNA repair.

Question 13

What are the names of fluoroquinolones type of drugs?

Answer 13

“floxacin”; ciprofloxacin, levofloxacin, moxifloxacin

Question 14

What type of bacteria is fluoroquinolones most effective with?

Answer 14

• gram negative;

- bactericidal

Question 15

What is the mechanism of action of sulfonamides?

Answer 15

• folic acid inhibitors; suppress bacterial growth by inhibiting the synthesis of folic acid or folate;
• bacteriostatic;
• broad spectrum both positive and negative bacteria

Question 16

What drug is commonly used to treat UTIs?

Answer 16

sulfamethoxazole-trimethoprim (Bactrim, Septra)

Question 17

What is the mechanism of action of tetracyclines?

Answer 17

• protein synthesis inhibitors; inhibiting bacterial protein synthesis by binding to the bacterial ribosome that slows microbial growth;
• bacteriostatic;
• one of the broadest spectrum drug class both effective in gram-negative and positive bacteria

Question 18

What is the mechanism of action of macrolides?

Answer 18

• protein synthesis inhibitors; inhibiting bacterial protein synthesis by binding to the bacterial ribosome that slows microbial growth;
• low doses bacteriostatic; high dose bactericidal
• mostly gram-positive bacteria

Question 19

What is the mechanism of action of aminoglycosides?

Answer 19

• protein synthesis inhibitors; inhibiting bacterial protein synthesis by binding to the bacterial ribosome that slows microbial growth;
• bactericidal;
• treatment of aerobic gram negative bacteria, mycobacteria, and some protozoans
• clinical use limited due to ototoxicity and nephrotoxicity

Question 20

What kind of drugs are the tetracyclines?

Answer 20

“cyclines” demeclocycline, doxycycline, minocycline, tegecycline

Question 21

What kind of drugs are the macrolides?

Answer 21

“romycin” erythromycin, azithromycin, clarithromycin

Question 22

Name 3 the aminoglycosides drugs?

Answer 22

gentamicin, tobramycin, streptomycin

Question 23

What is bacterial resistance?

Answer 23

when bacteria change in some way that reduces or eliminates the effectiveness of the antibiotic drug

Question 24

How does bacterial resistance occur?

Answer 24

1) genetic mutation such as enabling bacteria to produce enzymes that inactivate antibiotics (e.g., penicillin resistance occurred by bacteria producing enzyme called beta lactamases that cleaves off the beta lactam ring of penicillin to inactive the drug.
2) Acquiring resistance from another bacterium through simple mating process called conjugation that transfer genetic material.

Question 25

What is host flora and how it relates to bacterial infections?

Answer 25

- (undergrowth) antibiotics destroy normal microorganism that serve antibacterial substances by competing with pathogenic organisms for space and nutrients. Removal of host flora by an antibiotic gives remaining microorganism an opportunity to grow, allowing for overgrowth of pathogenic microbes. As a result, superinfections could occur introducing new pathogens. Superinfections are a new infection caused by an organism different from the on causing the initial infection. - (overgrowth) host flora themselves can cause disease if allowed to proliferate without control or if they establish colonies in abnormal locations. For example, E coli is part of the host flora in the colon but can become a serious pathogen if it enters the urinary tract. Host flora may also become pathogenic if the patient's immune system becomes suppressed called opportunistic infections.

Question 26

What are host factors in regards to bacterial infections?

Answer 26

- immunocompromised: suppressed immune systems may require aggressive antibiotics or prophalysis treatment with bactericidal medications. - blood brain barrier-infections of the CNS are difficult to treat in that many drugs cannot cross the BBB. - tissue environment-injury or inflammation can cause tissue to become acidic or anaerobic and to have poor circulation or barriers like excessive pus formation or hematomas can block drugs from reaching their targets. - intracellular pathogens-mycobacterium tuberculosis, salmonella, toxoplama, and listeria may reside intracellularly and may be difficult to reach in high concentrations. - allergies to antibiotics - age-unable to metabolize or excrete antibiotics - pregnancy status-some antibiotics cross the placenta and cause birth defeats - genetics-some patients lack certain enzymes used to metabolize antibiotics.

Question 27

What is the most versatile group of antifungals and why?

Answer 27

The azole class is the largest and most versatile group of antifungals. These drugs have a broad spectrum and are used to treat nearly any systemic or superficial fungal infection.

Question 28

What are the names of antifungal drugs?

Answer 28

"azole" fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend).

Question 29

What is the mechanism of action of vancomycin?

Answer 29

- inhibiting proper cell wall synthesis in Gram-positive bacteria; - treatment of MRSA

Question 30

What drugs are effective against staph infections?

Answer 30

Penicillinase-resistant penicillins (flucloxacillin, dicloxacillin) remain the antibiotics of choice for the management of serious methicillin-susceptible S. aureus (MSSA) infections, but first generation cephalosporins (cefazolin, cephalothin and cephalexin), clindamycin, lincomycin and erythromycin have important therapeutic roles in less serious MSSA infections such as skin and soft tissue infections or in patients with penicillin hypersensitivity, although cephalosporins are contra-indicated in patients with immediate penicillin hypersensitivity (urticaria, angioedema, bronchospasm or anaphylaxis).

Question 31

``` What are the class of drugs for the treatment of vancomycin-resistant Enterococcus faecium infections? ```

Answer 31

- streptogramins | - Quinupristin/dalfopristin (Synercid)

Question 32

What is the most common protozoan disease and what drugs are used to treat it?

Answer 32

- amebiasis | - metronidazole (Flagyl) and tinidazole (Tindamax)

Question 33

What is the most common parasite illness?

Answer 33

- worldwide-ascariasis which is caused by the roundworm Ascaris lumbricoides - U.S.-enteriobiasis-pinworm Enterobius vermicularis

Question 34

What is the most common drugs to treat helminth (parasite) illnesses?

Answer 34

For ascariasis, oral mebendazole (Vermox) | For enterobiasis, albendazole (Albenza) or pyrantel (Antiminth)

Question 35

What does cholinergic agonists do?

Answer 35

Stimulate the parasympathetic nervous system (rest and digest)

Question 36

What does effects do parasympathetic division control?

Answer 36

``` constricts pupil (miosis) stimulates salivation slows heart rate and contractility constricts bronchioles stimulates digestion contracts bladder stimulates erection & vaginal lubrication ```

Question 37

What does effects do sympathetic division control?

Answer 37

``` dilates pupil (mydriasis) inhibits salivation accelerates heart rate and contractility dilates bronchioles inhibits digestion stimulates release of glucose secretes epinephrine and norepinephrine relaxes bladder stimulates ejaculation and orgasm ```

Question 38

What does cholinergic antagonists do?

Answer 38

blocks the parasympathetic nervous system (effects similar to SNS)

Question 39

What type of drugs are cholinergic agonists?

Answer 39

bethanechol (Urecholine) -direct acting parasympathomimetics: bind to cholinergic receptors physostigmine (Antilirium) -cholinesterase inhibitors: inhibit the breakdown of Ach by inhibiting AchE

Question 40

What type of drugs are cholinergic antagonists?

Answer 40

Atropine muscarinic receptors to block effects (anticholinergic effects)

Question 41

What are the types of cholinergic antagonists?

Answer 41

muscarinic antagonist and nicotinic antagonist - their effects include: dilation of the pupils (mydriasis) , increase in heart rate, drying of glandular secretions, and relaxation of the bronchi (asthma treatment)

Question 42

Describe a seizure

Answer 42

clinical detactable sign of epilepsy, disturbance of electrical activity in the brain that may affect consciousness, motor activity, and sensation

Question 43

What are convulsions?

Answer 43

involuntary, violent spasms of large skeletal muscles of the face, neck, arms and legs.

Question 44

What is epilepsy?

Answer 44

neurological disorder, seizure disorder, two or more episodes of unprovoked seizures

Question 45

What are the classes of anti-seizure medications?

Answer 45

- Drugs that potentiate GABA action: stimulate an influx of Cl- ions through the GABA receptor channel; * barbiturates: phenobarbital (Luminal) and * benzodiazepines: diazepam (Valium) - Drugs that suppress sodium influx * hydantoins: phenytoin (Dilantin) * phenytoin-related drugs: valproic acid (Depakene) - Drugs that suppress calcium influx * succinimides: ethosuximide (Zarontin) - Amino Acid compounds: keep positive ions fluxes balanced * taurine, acetazolamide (Diamox), lacosamide (Vimpat)

Question 46

Why is drug compliance important in pharmcotherapy of epilepsy and seizures?

Answer 46

It is important to take antiseizure medications as prescribed, at the same time everyday as abruptly stopping medications can cause withdrawal seizures. These medications need to be discontinued over a period of 6-12 weeks.

Question 47

What is the mechanism of action of central acting skeletal muscle relaxants?

Answer 47

increases circulating levels of norepinephrine (NE), blocking presynaptic uptake, alpha 2 adrenergic agonists

Question 48

What is a type of central acting skeletal muscle relaxant drug?

Answer 48

cyclobenzaprine (Flexeril)

Question 49

What is the contraindication of central acting skeletal muscle relaxants?

Answer 49

MI, dysrhythmias, hypothyroidism, severe cardiovascular disease

Question 50

What is the mechanism of action of direct-acting antispasmodics?

Answer 50

works at the level of the neuromuscular junction and skeletal muscles; interferes with release of calcium in skeletal muscles

Question 51

What is a type of antispasmodic drug?

Answer 51

dantrolene sodium (Dantrium)

Question 52

What are the contraindications of Dantrolene sodium (Dantrium)?

Answer 52

impaired cardiac, pulmonary or hepatic function

Question 53

What is the mechanism of action of skeletal muscle relaxants for short term procedures?

Answer 53

depolarizing blockers used for ECT and endotracheal intubation

Question 54

What are the precautions associated with succinylcholine?

Answer 54

Adverse effects include persistent paralysis in some patients, elevated blood levels of potassium, malignant hyperthermia, and postoperative muscle pain.