|
‘Flouoroquinolones’ are specialized
antimicrobials which should be used only for specific conditions. Due to
misuses of 2nd and 3rd line antimicrobials for treating ordinary
infections, the bacterial population has developed resistance and we are
loosing cost-effective useful antimicrobials. Recently there is hardly
any addition of new antimicrobials and if there is anyone that is too
expensive. We lost streptomycin, very cost effective first line anti TB
drug, due to its misuse in treating ordinary infections. The other amino
glycosides amikacin and kanamycin are too expansive and have a lot of
toxicity and are reserved to treat resistant tuberculosis.
Enteric group of fever are a very prevalent and serious problem in
Pakistan. The causative salmonella organisms became resistant to
cost-effective and relatively safe first line antimicrobials like
ampicilin, amoxicillin, cotrimoxazole, chloramphenicol and furazolidine
due to their wide spread misuse. Now the salmonella and the related
organisms are becoming resistant to Flouoroquinolones due to their
enormous misuse in treating simple infections which should be treated
with first-line antimicrobials. They are even misused for treating viral
infections and even non-infections diseases like dietetic diarrhoea,
allergic disorder involving eyes, throat etc. One of the important role
in the misuse is the aggressive irrational promotional material which
recommends their use for every type of infection. Unfortunately there is
no control over disinformation by the Ministry of Health which is duty
bound to protect the vital interest of the citizen.
Flouoroquinolones should not be used to treat ordinary infections of
skin and related structures, ordinary respiratory tract, urinary tract
and abdominal infections. For ordinary urinary tract infections, many of
which are self-limiting, simple drugs like nitrofurantoin, syraprim
should be used. Unfortunately the cost-effective essential drug
nitrofurantoin is not available in Pakistan. The non-availability of
essential drugs is one of the major causes of misuse of drugs in
Pakistan. For ordinary respiratory and abdominal infections first line
antimicrobials like erythromycin, amoxicillin, tetracycline, first
generation cephalosporins, imidazoles etc should be used. For moderate
and serve chest and abdominal infections amoxiclav, 2nd and third
generation cephalosporin’s may be used. Second and third generation
Flouoroquinolones may be used to treat these infections when the
organisms are not sensitive to the other antimicrobials.
Flouoroquinolones should be reserved as far as possible to treat enteric
group of fevers and resistant tuberculosis.
Second generation Flouoroquinolones like ciprofloxacin and ofloxacin are
quite effective against gram-negative organisms, in fact more effective
against P. pyocyaneus than the 3rd generation Flouoroquinolones but less
effective against gram-positive organisms than the 3rd generation
Flouoroquinolones. However 3rd generation Flouoroquinolones are not
effective against MRS organisms. Regarding the third generation
Flouoroquinolones levofloxacin is the most cost-effective drug.
Moxifloxacin is very expensive and also has no advantage over
levofloxacin. With regards to efficacy and side effects Moxifloxacin has
far more toxic effects. It increases the risk of ventricular arrhythmias
when used with amiodarone, disopyramide, procainamide, parenteral
erythromycin, tricyclics, antihistaminic misolastine, chloroquine,
hydroxychlorquine, mefloquine, quinine, haloperidol, phenothiazine,
pimozide, serpindole, artomexetine, pentamidine, (BNF.55, Appendix 1
Page 749)
Due to serious interactions their use is contraindicated in combination
with these drugs. It should be noted that the drugs mentioned in the
above-cited list are very much in common use. Moxifloxacin use is
contraindicated in patients with history of QT interval prolongation,
bradycardia, history of symptomatic arrhythmia, heart failure with
reduced left ventricular ejection fraction, electrolytes disturbances, (BNF
55, page 318). It is only licensed in the UK as a second line drug for
community acquired pneumonia, exacerbations of chronic bronchitis and
sinusitis. While levofloxacin is licensed for use in other disorders as
well like urinary tract infections, prostatitis, and complicated soft
tissue infections. Second generation quinolones are also licensed for
use in surgical prophylaxis, meningococcal disease prophylaxis,
pseudomonal infections, gonorrhea, anthrax etc.
In conclusion, Flouoroquinolones should be used very discreetly. Already
there are signs of development of bacterial resistance to
Flouoroquinolones due to their misuse. Enteric fever is a serious
problem in Pakistan. If Flouoroquinolones become ineffective like
earlier drugs then there will be no effective drug to tackle enteric
infections. Flouoroquinolones should be used for serious infections
preferably based on culture and sensitively studies and where other
antimicrobials can not be used. For gram negative bacterial infections
second generation Flouoroquinolones ciprofloxacin, ofloxacin should be
used. Third generation Flouoroquinolones can be used for infections when
there is also infection with gram positive organisms. It should be kept
in mind that the third generation Flouoroquinolones is not effective
against MRS organism. It should also be noted that the 3rd generation
Flouoroquinolones are not included in the WHO Essential Drug list.
Amongst the 3rd generation Flouoroquinolones, levofloxacin is cost
effective; one can treat a patient with levofloxacin at a cost of a
fraction of Moxifloxacin. Moxifloxacin also has high toxicity on the
cardiovascular system and has serious interactions with many drugs
including the ones in common use. Its general use should be avoided
keeping in mind also that it is licensed for use only for limited
conditions and that too as a second line drug. |
