Moxifloxacin: (mox'' i flox' a sin)

                                                                                                         
It’s a 4th generation floroquinolons antibiotic.mostly available in oral dosage form (Avelox) but in some countries parentral and ophthalmic prepration (Vegamox) are also use.marketed in hydrochloride form.


Use of this drug is quite limited because of certain side effects;
(it is contra indicated with many drugs as well as some herbal products) it is used in last when no antibiotic is effective.
Systematic (IUPAC) name:
1-cyclopropyl-7-[(1S,6S)-2,8-diazabicyclo
[4.3.0]non-8-yl]-6-fluoro-8-methoxy-4-oxo- quinoline-3-carboxylic acid
Available form:

Oral, IV, local (eyedrops)

Mechanism of action:

Moxifloxacin is a broad-spectrum antibiotic that is active against both Gram-positive and Gram-negative bacteria. It inhibits DNA gyrase, a type II topoisomerase, and topoisomerase IV, enzymes necessary to separate bacterial DNA, thereby inhibiting cell replication.

Advantages of moxifloxacin over other floroquinolons:
The most apparent advantage of the IV generation lies in the fact that the drugs act by inhibiting topoisomerases II and IV in both +ve & -ve. (Whereas other floroquinolons were active against topoisomerase IV in gm +ve and topoisomerase II in gm -ve) 

It would therefore appear that resistance to these drugs may not occur as a spontaneous mutation at two levels at once.

Resistance: 

A possible mechanism of drug resistance development to this generation has been postulated - resistance at the bacterial cell wall by increased eflux (remains to be seen).
 
Uses:

• Respiratory tract infections
• Cellulitis, anthrax
• Intra-abdominal infections
• Endocarditis
• Meningitis
• Tuberculosis
• Conjunctivitis

FDA has approved this drug in

• Acute Exacerbations of Chronic Bronchitis (AECB) (restricted use)
• Acute Bacterial Sinusitis (ABS) (restricted use)
• Community Acquired Pneumonia (CAP)(restricted use)

Additional indications were approved by the FDA as follows:

• April 2001: Uncomplicated Skin and Skin Structure Infections (uSSSI)
• May 2004: Community Acquired Pneumonia caused by multi-drug resistant Streptococcus pneumonia.
• June 2005: Complicated Skin and Skin Structure Infections (cSSSI)
• November 2005: Complicated Intra-Abdominal Infections (cIAI).

Note:
Moxifloxacin only be prescribed when other antibiotics that have been initially recommended for treatment cannot be used or have failed.
Moxifloxacin only be prescribed when other antibiotics that have been initially recommended for treatment cannot be used or have failed.

Unnecessary use or overuse of any antibiotic can lead to its decreased effectiveness. Do not share this medication with others.This medication has been prescribed for your current condition only. Do not use it later for another infection unless told to do so by your doctor. A different medication may be necessary in that case.Laboratory and/or medical tests (e.g., liver function, complete blood count, blood glucose) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
       Donot use if you have:

• Doesn’t use in Liver complication, if necessary adjust its dose to its decreased quantity.
• If you have muscular weakness take this medicine with some supplements.
• If your body or body parts shivers (seizures) avoid it. 
• Do not use it in pregnancy it may harm the fetus.
• Don’t use if you are taking steroids.Drug interactions:

• NSAID, theophylline, warfarin (hepatic biotransformation)
• May be given after food, but not with chelating agents - upto 8 hours after taking antacids & 1-2 hours before taking antacids.
• Antacids (aluminum, calcium,or magnesium-containing)
• Laxatives (magnesium-containing, or sucralfate or Zinc)
• Ferrous sulfate and Bismuth salicylate

      Precautions:

• History of hypersensitivity to the quinolones (Steven Johnson's type syndrome may occur).
• For systemic administration - hepatic and renal impairment needs to be considered.
• Achilles tendinitis and tendon rupture reported 2-42 days after systemic administration.

• Contraindicated in pts. With history of convulsions.

• Pregnancy category C - NOT to be given to pregnant mothers, lactating mothers (Adequate animal studies, inadequate human studies).

     Pharmacokinetics:

• Approximately 52% of an oral or intravenous dose of moxifloxacin is metabolized via glucuronide and sulfate conjugation.
• The cytochrome P450 system is not involved in moxifloxacin metabolism.
• Half life is 11-15 hrs.
• Eliminate through urine and feces 45 % of the drug is excreted unchanged.

     Adverse effects:

Severe allergic reactions (rash; hives; itching)

1-Breathing problems:

 Difficulty breathing or swallowing; tightness in the chest; seizures; 

Swelling of the mouth, face, lips, or tongue; unusual hoarseness)
Bloody or tarry stools; burning,
2-Muscular problem:

Numbness, tingling, pain, or weakness of the arms, hands, legs, tiredness or weakness; or feet; cramps; seizures; decreased urination;

3-Heart problems:

Fainting; fast, slow, or irregular heartbeat;

4-Mental illness includes: hallucinations; mood or mental changes (eg, new or worsening anxiety, agitation, confusion, depression, nervousness, paranoia, restlessness); muscle pain or weakness; nightmares; suicidal thoughts or actions.

5-Liver problems:
Symptoms of liver problems (eg, dark urine; loss of appetite; pale stools; yellowing of the skin or eyes); tremor; trouble sleeping; unusual bruising or bleeding; unusual swelling or weight gain;
6-Unusual vaginal yeast infection
7-Vision changes:
Vision changes (eg, blurred vision).
8-Miscellaneous:
pain, soreness, redness, swelling, weakness, or bruising of a tendon or joint area; persistent sore throat; red, swollen, blistered, or peeling skin; severe or persistent diarrhea; severe or persistent dizziness, headache, or light-headedness; stomach pain.

9-Others:
Fever, chills, or unusual cough; inability to move or bear weight on a joint or tendon area; moderate to severe sunburn.