97 Questions
Which type of antibiotics are tetracyclines classified as?
Broad-spectrum
How do tetracyclines primarily inhibit bacterial growth?
Inhibit protein synthesis
What is the main difference between aminoglycosides and tetracyclines in terms of bactericidal action?
Aminoglycosides are bacteriostatic, tetracyclines are bactericidal
Why are all seven tetracyclines discussed as a group rather than individually?
The similarities among them outweigh their differences
At what concentrations are tetracyclines typically bacteriostatic?
Low concentrations
What is the primary mechanism through which tetracyclines inhibit bacterial growth?
Preventing amino acid addition to the growing peptide chain
Which of the following is NOT a common adverse effect associated with tetracyclines?
QT prolongation
What is the primary mechanism of action of macrolides?
Inhibition of protein synthesis
Which organism is tetracycline a first-line drug for?
Mycoplasma pneumoniae
What is the primary reason for the decline in the use of tetracyclines as antibiotics?
Increased bacterial resistance
Which of the following infections is clindamycin NOT indicated for?
Central nervous system infections
Which antibiotic class is Telithromycin a part of?
Ketolides
Why should tetracyclines not be administered with metal ions like calcium or iron?
To minimize interference with absorption
What is the principal indication for Dalfopristin?
Vancomycin-resistant enterococcus
Which gram-negative bacteria are macrolides generally active against?
Some gram-negative bacteria
Which antibiotic has a black box warning related to muscle weakness in patients with myasthenia gravis?
Telithromycin
What is a significant difference between tetracyclines and macrolides in terms of elimination from the body?
'Tetracyclines predominantly undergo renal elimination, whereas macrolides undergo hepatic elimination'
What is the common target organism for Aminoglycosides?
Pseudomonas aeruginosa
What is a significant adverse effect of Chloramphenicol?
Liver injury
Which antibiotic inhibits bacteria protein synthesis and requires parenteral administration for systemic infections?
Tigecycline
In which situation are Aminoglycosides like gentamicin, tobramycin, and amikacin typically used together with penicillins?
To enhance bacterial kill
Which antibiotic is specifically indicated for impetigo?
Mupirocin
'Ozenoxacin' belongs to which class of antibiotics?
Fluoroquinolones
Which antibiotic class has the drug interactions include MAOIs and SSRIs?
Oxazolidinones
Which antibiotic is primarily employed for anaerobic infections outside the CNS?
Clindamycin
Why is clindamycin considered the drug of choice for severe group A streptococcal infection?
Because it suppresses the synthesis of bacterial toxins
Which antibiotic has activity against multidrug-resistant gram-positive pathogens such as VRE and MRSA?
Linezolid
What is a significant risk associated with prolonged linezolid therapy?
Reversible myelosuppression
Which antibiotic is specifically used to treat skin and soft tissue infections caused by MRSA and other bacterial species?
Tedizolid
Which antibiotic should generally be reserved for infections caused by VRE or MRSA?
Linezolid
Which antibiotic is not active against gram-negative bacteria?
Linezolid
What is the most common side effect associated with linezolid?
Diarrhea
What drug interaction should be considered when prescribing linezolid?
MAOIs
What condition should patients with phenylketonuria avoid taking linezolid oral suspension due to the presence of phenylalanine?
Pneumonia
Why should aminoglycosides not be given with other ototoxic or renal toxic drugs?
They may increase the risk of inner ear and kidney damage
Why is once-daily dosing preferred over divided doses for aminoglycosides?
It is more convenient for patients
When are peak levels measured for patients receiving aminoglycosides in divided doses?
30 minutes after giving an IM injection
Which bacteria are the primary targets for gentamicin?
Pseudomonas aeruginosa and Enterobacteriaceae
Why is gentamicin often preferred in hospitals where resistance is not a problem?
It is cost-effective compared to alternatives
What should be avoided when giving tobramycin to patients?
'Concurrent therapy with other ototoxic or nephrotoxic drugs'
'Amikacin is active against the broadest spectrum of gram-negative bacilli' - Why is this considered an outstanding feature of amikacin?
'It has less bacterial resistance'
'Why must gentamicin not be mixed with penicillins in the same parenteral solution?' What could be the possible outcome when they are mixed?
'It can cause inactivation of gentamicin'
'What is the advantage of amikacin being the least vulnerable to inactivation by bacterial enzymes?' How does this affect its efficacy?
'It reduces bacterial resistance'
'What infections is amikacin usually effective against?' Why might it be chosen over gentamicin or tobramycin?
'Infections that are resistant to gentamicin and tobramycin'
'What precautions should be taken when using gentamicin with other drugs?' How might these precautions impact treatment plans?
'Monitoring kidney function regularly'
Why are sulfonamide antibiotics still considered important despite being largely replaced by other agents?
They are the top choice for treating urinary tract infections
What is the key reason sulfonamides do not harm mammalian cells?
Mammalian cells have a different mechanism of folate synthesis than bacteria
What is the primary effect of sulfonamides on bacterial cells?
Disruption of folate synthesis
Why are bacteria more susceptible than mammalian cells to the effects of sulfonamides?
Bacteria cannot take up folate from the environment
How do sulfonamides affect the ability of bacteria to synthesize DNA, RNA, and proteins?
They interfere with the synthesis of essential cellular components in bacteria
What is the significance of sulfamethoxazole in combination with trimethoprim?
It has broad-spectrum antimicrobial properties
What is the principal indication for sulfonamides today?
Treatment of UTIs
Which adverse effect is most commonly associated with sulfonamides?
Hypersensitivity reactions
In which patients is hemolytic anemia a risk when using sulfonamides?
Those with G6PD deficiency
What disorder in newborns can be caused by sulfonamides due to bilirubin deposition in the brain?
Kernicterus
How can the risk for renal damage from crystalluria be reduced when using sulfamethoxazole?
By maintaining adequate hydration
Which antibiotic should NOT be administered to infants younger than 2 months?
Sulfamethoxazole
Why are long-acting sulfonamides banned due to hypersensitivity concerns?
They induce Stevens-Johnson syndrome
Which medication should not be used in patients with a history of severe hypersensitivity to sulfonamides, sulfonylureas, or diuretics?
Sulfacetamide
What is the primary mechanism through which sulfonamides can intensify the effects of warfarin, phenytoin, and oral hypoglycemics?
Inhibition of hepatic metabolism
Why should sulfonamides not be administered to pregnant patients after 32 weeks of gestation or to breastfeeding mothers?
To prevent kernicterus in newborns
How do the bacteriostatic and bactericidal effects of Nitrofurantoin differ?
Bacteriostatic at low concentrations and bactericidal at high concentrations
What is the main reason Nitrofurantoin is not recommended for upper urinary tract infections?
It is ineffective against upper tract infections
Why is Methenamine considered devoid of systemic toxicity?
It breaks down into ammonia and formaldehyde in acidic urine only
What adverse effect is specifically associated with Methenamine use in patients with renal and liver failure?
Renal toxicity
Why is Trimethoprim/sulfamethoxazole preferred over Methenamine for chronic lower urinary tract infections?
Methenamine lacks efficacy against chronic infections
Which drug interaction should be considered when prescribing Methenamine?
Urinary alkalinizers
What is the drug of first choice for uncomplicated cystitis?
Nitrofurantoin
Which antibiotic requires just one dose and is a good choice when adherence is a concern?
Fosfomycin
Which of the following is a common pathogen responsible for complicated UTIs?
Proteus
What is the recommended duration of treatment for pyelonephritis or UTIs with systemic involvement?
7-14 days
Which antibiotic is commonly used for long-term prophylaxis in recurrent UTIs?
Nitrofurantoin
What is a common causative organism in acute bacterial prostatitis cases?
E.coli
Which of the following is NOT a common symptom of acute bacterial prostatitis?
Tremors
'Most recurrent UTIs in females are due to' what?
'Reinfection'
'Prophylaxis should continue for at least 6 months' for what type of recurring infections?
'Recurrent UTIs'
'Acute bacterial prostatitis' is frequently associated with which of the following?
Indwelling urethral catheter
What is a potential adverse effect associated with TMP/SMZ therapy?
Kernicterus in neonates
Which population is unusually susceptible to TMP/SMZ toxicity?
Patients suffering from AIDS
What is the estimated prevalence of UTIs among women in their lifetimes?
60% - 80%
Which organism is responsible for over 80% of uncomplicated, community-associated UTIs?
Escherichia coli
What distinguishes complicated UTIs from uncomplicated UTIs?
Association with predisposing factors
In which type of infections is short-course therapy (3 days) recommended?
Uncomplicated, community-associated infections in women not pregnant
What is the primary target organism for single-dose therapy for UTIs?
Escherichia coli
'Suprapubic discomfort' is a common clinical manifestation of which type of UTI?
Upper urinary tract infection
Which bacterium is responsible for most hospital-associated UTIs?
Proteus species
What symptom differentiates asymptomatic upper UTI from acute cystitis?
Pyuria
What is the primary mechanism of action of mafenide?
Suppresses bacterial synthesis of DNA, RNA, and proteins
Why should mafenide be discontinued if severe acidosis occurs?
To prevent further metabolic acidosis
What is the main reason for avoiding facial application of silver sulfadiazine?
It causes skin discoloration
Which condition can be exacerbated by the application of mafenide?
Acidosis
What is a distinguishing feature of trimethoprim in terms of its antibacterial activity?
Primarily bacteriostatic against most gram-negative bacilli
Why is caution advised when administering trimethoprim to patients with preexisting folate deficiency?
To prevent megaloblastic anemia and neutropenia
What is the main concern with giving trimethoprim to patients with renal insufficiency?
Promotion of hyperkalemia
'What is the preferred or alternative medication for UTIs' based on the text?
'Trimethoprim-sulfamethoxazole (TMP/SMZ)'
'TMP/SMZ inhibits sequential steps in' what process?
'Tetrahydrofolate synthesis'
'What is a key adverse effect that might occur with routine use of TMP/SMZ?'
'Nausea and vomiting'
Test your knowledge on clindamycin and its effectiveness in treating anaerobic infections caused by organisms such as Bacteroides fragilis, Fusobacterium species, and Clostridium perfringens. Explore its bacteriostatic and occasionally bactericidal nature, as well as issues related to resistance and its use as an alternative to penicillin.
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