Chapter 38- Antibiotics Part One

Question 0

What are macrolides?

Answer 0

A bacteriostatic antibiotic that may be bacteriocidal to some bacteria;

Ex: Erythromycin, and Azithromycin, Clarithromycin- these two have longer durations of action than erythromycin

Question 1

Bacteriostatic antibiotic

Answer 1

Antibiotics that do not actually kill bacteria but rather inhibit the growth (p. 614)

Question 2

Drug profile:

Amoxicillin

Answer 2

– Aminopenicillin
- Mech of Action: inhibits cell wall synthesis; bacteriostatic
– Treats infections in the ears, nose, throat, genitourinary tract, skin, and skin structures.
– Route: PO
– Onset of action: 0.5-1 hr
– Peak plasma concentration: 1-2 hr
– Elimination of half-life: 1-1.5 hr
– Duration of action: 6-8 hr

P. 619

Question 3

Drug profile:

Ampicillin

Answer 3

– Aminopenicillin
-Treats: ear infections and respiratory infections such as sinusitis caused by bacteria, acute exacerbations of COPD, epiglottis, UTIs, meningitis, and salmonella infections,
– Available in three different salt forms: anhydrous, trihydrate, and sodium
– Route: anhydrous and trihydrate PO; sodium IV
–Onset of action: PO=variable, PO=variable
– Peak plasma concentration: PO=1-2hr; IV= 5 min
– Elimination half-life: PO 1-1.5 hr; IV 1-1.8 hr
– Duration of action: PO 4-6 hr; IV 6-8 hr

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Question 4

What are aminopenicillins?

Answer 4

– Presence of a free amino group (NH_2) which causes
– Enhanced activity against gram-negative bacteria
– Also effective against some gram-positive organisms
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Question 5

What are Sulfonamides?

Answer 5

– One of the first groups of drugs used as antibiotics.
– Only sulfamethoxazole combined with trimethoprim ( a nonsulfonamide antibiotic), known as Bactrim, Septra, or co-trimoxazole (SMX-TMP), is used in clinical practice
– Mechanism of action and drug effects:
bacteriostatic drugs- inhibits bacterial synthesis of folic acid
– Indications:
broad spectrum of antibacterial activity, against both gram-positive and gram-negative organisms
Often utilized for prophylaxis and treatment of opportunistic infections in HIV patients; for outpatient staphylococcus infections
– Contraindications:
known drug allergy–> alternatives are sulfonylureas, thiazide & loop diuretics, and carbonic anhydrase inhibitors
– Adverse Effects:
Common cause =allergic reaction, photosensitivity, Mucocutaneous, G.I., hepatic, renal, hematologic complications
– Interactions:
Sulfonylureas, phenytoin, warfarin, cyclosporine-induced nephrotoxicity

Question 6

1. What are Beta-Lactam antibiotics 2. and what are the subclasses?

Answer 6

– So named because of the beta-lactam ring that is part of their chemical structure
– Includes four major subclasses: penicillins, cephalosporins, carbapenems, and monobactams

Question 7

Beta-lactamase:

Answer 7

Some bacterial strains produce this enzyme. Provides a mechanism for bacterial resistance to beta-lactam antibiotics.
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Question 8

Beta-lactamase inhibitors:

Answer 8

Drugs added to beta-lactam antibiotics to make the drug more powerful against beta-lactamase-producing bacterial strains
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