Chloramphenicol, Tetracycline, Erythromycin Flashcards by Iseoluwa Ojo

TETRACYCLINES

History: _________ was 1st introduced in 1948. 2 years later, _________ became available.

Chlortetracyline

oxytetracycline

How well did you know this?

Not at all

Perfectly

Sources
Chlortetracycline is from ________
Oxytetracycline is from ______

Streptomyces
Streptomyces

How well did you know this?

Not at all

Perfectly

Tetracycline is created _____________ from _________ and from a species of ________

Semi-synthetically

Chlortetracycline

Streptomyces

How well did you know this?

Not at all

Perfectly

Demeclocycline is a product of a mutant strain of ____________

Streptomyces Aureofaciens

How well did you know this?

Not at all

Perfectly

Mention 3 semi synthetic cycline derivatives

Metha

Doxy

Mino

How well did you know this?

Not at all

Perfectly

Tetracyclines are usually drugs of choice for bacterial infections.

T/F

They are not

How well did you know this?

Not at all

Perfectly

Tetracyclines

The more lipo____ drugs, ______ and ______ usually are the most active by weight, followed by _______.

Philic

minocycline and doxycycline

tetracycline

How well did you know this?

Not at all

Perfectly

Resistance of a bacterial strain to any one member of the class usually results in __________ to other tetracyclines.

cross resistance

How well did you know this?

Not at all

Perfectly

Tetracyclines are bacteri_____agents.

Ostatic

How well did you know this?

Not at all

Perfectly

Tetracyclines

Rapidly multiplying micro-organisms are least affected.

T/F

Most

How well did you know this?

Not at all

Perfectly

Tetracyclines

Order of activity : ??

Minocycline

Doxycycline

Tetracycline

Oxytetracycline

How well did you know this?

Not at all

Perfectly

In general gram- _____ micro organisms are affected by lower conc. of tetracycline than are grain –______ special agents.

positive

negative

How well did you know this?

Not at all

Perfectly

Neisseria gonorrhoea and many strains of N.meningititis are still inhibited by tetracyclines

Neisseria gonorrhoea and many strains of N.meningititis were initially inhibited by tetracyclines though sensitivity patterns changed over the
years.

How well did you know this?

Not at all

Perfectly

Tetracyclines

Mechanism of Action: Site of action is the ___________, inhibiting ______

bacterial ribosome 30S

protein synthesis.

How well did you know this?

Not at all

Perfectly

Absorption, distribution, and Excretion

Most tetracyclines are (adequately or inadequately?) but (completely or incompletely?) absorbed from the GIT.

Most absorption takes place from ________________ and is greater in the ________ state, though more recent studies show that ______ is well absorbed after food and this _______________

adequately

incompletely

stomach and upper small intestine

fasting; doxycycline

even prevents or ameliorates the GIT disturbance initially associated with its administration.

How well did you know this?

Not at all

Perfectly

Doxycycline

The drug accumulates with resultant high concentrations in the GIT following repetitive dosing such that many aerobic and anaerobic coliform micro-organisms and gram-positive _______ bacteria are _____.

Consequently, the _______ is altered, the stools become ______,______ and acquire a ____,_____ colour.

Diarrhea can also occur and
ocassionally, pseudomembranous colitis may occur.

Spore-forming

suppressed

intestinal flora

softer, odourless

yellow-green

How well did you know this?

Not at all

Perfectly

Tetracycline

Absorption is impaired by ___ products, _______ gels, Nabicarbonate, ____ salts, ____ preparations.

There is irregularity of absorption from GIT hence a wide range of plasma conc in different individuals ff oral administration.

milk

aluminium hydroxide

calcium; iron

How well did you know this?

Not at all

Perfectly

They can be divided into 3 groups based on the dosage and frequency of oral administration required to produce effective plasma concentration.

Oxytetracycline and Tetracycline – Adults ___mg 6 hly

methacycline – ___mg 6 hly.

Deoxycycloine and minocycline – ____mg every 12 hours in 1st 24 hours ff by 100mg once a day or twice daily when infection is severe.

250

150

100

How well did you know this?

Not at all

Perfectly

Food does not interfare with the absorption of doxycycline and minocycline.

T/F

How well did you know this?

Not at all

Perfectly

The volume of distribution of many of the tetracycline is relatively larger than that of the body water.

T/F

How well did you know this?

Not at all

Perfectly

Tetracycline

They are all concentrated in the ____ and
excreted by way of the ____ into the intestine from which they are ___________

liver

bile; partially reabsorbed.

How well did you know this?

Not at all

Perfectly

Minocycline reaches a sufficient conc in ______ and _____ to eradicate the meningococcal carrier state.

tears and saline

How well did you know this?

Not at all

Perfectly

High conc of tetracycline is found in fetal circulation and breast milk.

T/F

How well did you know this?

Not at all

Perfectly

Tetracycline

They are stored in _____ cells of the liver, spleen, and bone marrow and in bone and the __________________

main route of excretion is the _____, also in ____.

reticuloendothelial

dentine and enamel of unerupted teeth.

kidney; faeces

How well did you know this?

Not at all

Perfectly

Tetracycline Preps, Routes – usually _____ and some by _______. Topical administration restricted to use on ______ because of a high risk of _____. Never inject _______ and rarely given ________.

oral capsules I.V injection the eye; sensitization intrathecally intramuscularly

Tetracycline UNTOWARD EFFECTS ____ irritation, ______ burning and stress, ______ discomfort, nausea, and vomiting. The larger the dose the greater the likelyhood of an irritative reaction. __________, ______ toxicity, ______ toxicity.

GIT Epigastric abdominal Photocoxicity; hepatic; Renal

Tetracycline UNTOWARD EFFECTS _______ then _______ discolouration of teeth if administered up to ___ years, however, generally most authorities agree that it should not be administered to children up to ____ years of age. The deciduous teeth are at the greatest danger affected if given from ___________ to _______ of the postnatal period, while the greatest danger to the permanent teeth coloration occurs if given between the ages of ______ and _______ . Super infection.

Yellowish then Brownish; 8 12 mid- pregnancy to 4/6 months 2 months and 5 years

CHLORAMPHENICOL History: produced by _________

streptomyces venezuelae

Mechanism of action: Chloramphenicol inhibits ______ in bacteria by binding (reversibly or irreversibly?) to the ___S ribosomal subunit near the site of action of the _______ antibiotics and _______, which it inhibits (competitively or non competitively?) . It also inhibits _______ protein synthesis in _______ cells

protein synthesis reversibly 50 macrolide; clindamycin Competitively ; mitochondrial; mammalian

Chloramphenicol Resistance has been growing, in the case of gram negative bacteria it is due to the presence of a specific _____ acquired, a specific _______ inactivates the drug.

plasmid acetyl transferase

Absorption, Distribution, Fate and Excretion Two forms are available for oral administration (1) the _________ and (2) the ___________ Hydrolysis of (2) occurs rapidly and almost completely by __________ in the ___________.

active drug prodrug chloramphenicol palmitate pancreatic lipases duodenum

Chloramphenicol Bioavailability is greater for the proactive drug than active drug

F Active is more than proactive

Chloramphenicol Absorption of I.M. is usually not ________, however, I.V. of the parenteral form succinate is as suitable as P.O. or I.M., Clearance is by the _____ hence ____ insufficiency, poor ______ function in neonates lead to conc. In plasma. This is well distributed in body fluids and readily reaches therapettic conc in CSF (____% of plasma) in the presence or absence of meningitis.

predicable kidney; renal; renal 60

Chloramphenicol Doesn’t readily traverse the placental barrier and is not secreted in milk. T/F

The major route of elimination of chloramphenicol is _____ metabolism to the inactive _______. This metabolite as well as cholamphenicol is excreted in ______.

hepatic; glucoromide Urine

THERAPUTIC USES of chloramphenicol ____________ when the strains causing the organism are susceptible though the use of other newer drugs which usually do not possess serious untoward effects and can be administered for shorter periods has overtaken chloramphenicol in this regard.

Typhoid fever

Chloramphenicol therapeutic uses It was very valuable against ______ infection especially ______ and ________, but it is now rarely indicated because of the ___________

bacterial anaerobic intra-abdominal and brain abscesses availability of numerous equally effective and less toxic alternative.

Chloramphenicol Used in _______ diseases when tetracycline cannot be used.

Rickettsial

Chloramphenicol Hematological Toxicity: Type A ADVERSE DRUG REACTION presenting as _________ Type B ADVERSE DRUG REACTION presenting as _______ Type C ADVERSE DRUG REACTION presenting as ________ Type D ADVERSE DRUG REACTION presenting as _______. This occurs sometime after the patient has taken the drug.

dose related anaemia. aplastic anemia anemia after chronic administration aplastic anaemia

Chloramphenicol In Type B ADVERSE DRUG REACTION These patients present in ______ fashion. Who develops anemia cannot be predetermined, the duration of drug use may not be commensurate with _________ or _______

an unpredictable develop of anemia or depth of anemia

Gray baby syndrome can occur in adults T/F

Chronic administration of ____ or acute administration of ______ shortens the t1/2 of chloramphnicol leading to sub-theraputic concentrations of the drug

phenobarbital rifampin

Erythromycin is produced by a strain of ______________(formerly _________ ) and belongs to the ________ group of antibiotics.

Saccharopolyspora erythraea Streptomyces erythraeus macrolide

Erythromycin is (acidic or basic?) and readily forms salts with acids.

Basic

Erythromycin is a white to off-white powder, _______ in water, and _______ in alcohol, chloroform, and ether

slightly soluble soluble

The passage of the erythromycin across the blood-brain barrier _____eases in meningitis.

Incr

Erythromycin crosses the placental barrier fetal plasma levels of erythromycin are high. Erythromycin is excreted in human milk. Erythromycin is removed by peritoneal dialysis or hemodialysis. T/F

T F(low) T F(it’s not)

In the presence of normal hepatic function, erythromycin is concentrated in the _____ and is excreted in the _____

liver; bile

the effect of hepatic dysfunction on biliary excretion of erythromycin is known. Mention it

It’s not known

After oral administration, less than ___% of the administered dose can be recovered in the active form in the urine.

Optimal blood levels are obtained when Erythromycin Base Filmtab tablets are given in the _____ state (at least ____________________).

fasting 1⁄2 hour and preferably 2 hours before meals

Erythromycin acts by inhibition of protein synthesis by binding ___ S ribosomal subunits of susceptible organisms.

Erythromycin does not affect nucleic acid synthesis. T/F

Many strains of ___________ are resistant to erythromycin alone but are susceptible to erythromycin and _____ used concomitantly.

Haemophilus influenzae sulfonamides

Tetracycline is effective against ____,______,______,______

Ricketssiae Chlamydia Mycoplasma Atypical Mycobacteria

Chloramphenicol can be exerted through the breast milk Tetracycline can be excreted through the breast milk Erythromycin can be excreted through the Breast milk T/F

T T T

Chloramphenicol is mainly used to treat ________ But can also be used to treat _____ when ———- isn’t available

Typhoid fever Ricketssiae; tetracycline

Tetracycline- acidic or basic? Erythromycin- acidic or basic?

Acidic Basic

Mention 2 other drug classified with erythromycin?

Clarithromycin Azithromycin

Chloramphenicol is effective against anerobic organisms T/F

Chloramphenicol can inhibit clindamycin competitively because both have similar mechanism of action T/F

Chloramphenicol may cause hepatotoxicity T/F

Aminoglycosides = only against gram ____,_____ ; ____- spectrum Chloramphenicol: ____ spectrum; preferred for ______

neg aerobes; narrow broad; anaerobes

Tetracyclines = _____ spectrum; preferred for _______

broad intracellular microbes

Chloramphenicol: by ____,___,______ (Poorly or well ?) absorbed; relatively fairly distributed . Loves the ____,____,_____ ; metabolized in the liver; excreted in kidney and breast milk

oral, IV, topical Well placenta, cns, breast.

Tetracycline: by mainly ____ but also ____; good absorption ; poorly distributed, loves the _____, and _______ ; kidney and liver excretes them

oral; IV bones and teeth

Macrolide administration: ____ and ——— ; (complete or incomplete?) absorption ; well distribution; well found in placenta; excreted through the kidney

oral and IV Incomplete

Aminoglycosides = inhibit ____ stage Chloramphenicol = inhibits _____ Tetracycline = inhibits _____ Macrolide= inhibits _____

initiation transpeptidation elongation translocation

Chemistry Aminoglycosides = ______________ Chemistry of chloramphenicol =_________ Chemistry of tetracycline = —————— Chemistry of macrolide=_______ + ________

2amino sugar + 2 deoxystreptamin nitrobenzene ring 4 naphthalene carboxamide lactose ring+ sugar

Bacterio____ - Aminoglycosides Bacterio_____-tetracycline Bacterio______- chloramphenicol

cidal static Static