Nox

A synthetic fluoroquinolone (fluoroquinolones) with broad-spectrum antibacterial activity against most gram-negative and gram-positive bacteria. Nox inhibits bacterial DNA gyrase. [PubChem]

Nox is indicated for the treatment of adults with the following infections caused by susceptible strains of the designated microorganisms:

Urinary tract infections

Uncomplicated urinary tract infections (including cystitis) due to Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus epidermidis, Staphylococcus saprophyticus, Citrobacter freundii1, Enterobacter aerogenes1, Enterobacter cloacae1, Proteus vulgaris1, Staphylococcus aureus1, or Streptococcus agalactiae1.

Complicated urinary tract infections due to Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, or Serratia marcescens1.

Sexually transmitted diseases

Uncomplicated urethral and cervical gonorrhea due to Neisseria gonorrhoeae.

Prostatitis

Prostatitis due to Escherichia coli.

Penicillinase production should have no effect on Nox activity.

Appropriate culture and susceptibility tests should be performed before treatment in order to isolate and identify organisms causing the infection and to determine their susceptibility to Nox. Therapy with Nox may be initiated before results of these tests are known; once results become available, appropriate therapy should be given. Repeat culture and susceptibility testing performed periodically during therapy will provide information not only on the therapeutic effect of the antimicrobial agents but also on the possible emergence of bacterial resistance.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Nox and other antibacterial drugs, Nox should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Nox is used to treat certain bacterial infections in many different parts of the body. Nox may mask or delay the symptoms of syphilis. It is not effective against syphilis infections.

Nox belongs to the class of medicines known as quinolone antibiotics. It works by killing bacteria or preventing their growth. However, Nox will not work for colds, flu, or other virus infections.

Nox is available only with your doctor's prescription.

Tablets Nox should be taken at least one hour before or at least two hours after a meal or ingestion of milk and/or other dairy products. Multivitamins, other products containing iron or zinc, antacids containing magnesium and aluminum, sucralfate, or Videx® (Didanosine), chewable/buffered tablets or the pediatric powder for oral solution, should not be taken within 2 hours of administration of Nox. Tablets Nox should be taken with a glass of water. Patients receiving Nox should be well hydrated.

Normal Renal Function

The recommended daily dose of Nox is as described in the following chart:

Renal Impairment

Nox may be used for the treatment of urinary tract infections in patients with renal insufficiency. In patients with a creatinine clearance rate of 30 mL/min/1.73 m² or less, the recommended dosage is one 400-mg tablet once daily for the duration given above. At this dosage, the urinary concentration exceeds the MICs for most urinary pathogens susceptible to Nox, even when the creatinine clearance is less than 10 mL/min/1.73 m².

When only the serum creatinine level is available, the following formula (based on sex, weight, and age of the patient) may be used to convert this value into creatinine clearance. The serum creatinine should represent a steady state of renal function.

Elderly

Elderly patients being treated for urinary tract infections who have a creatinine clearance of greater than 30 mL/min/1.73 m² should receive the dosages recommended under Normal Renal Function.

Elderly patients being treated for urinary tract infections who have a creatinine clearance of 30 mL/min/1.73 m² or less should receive 400 mg once daily as recommended under Renal Impairment.

How supplied

No. 8338 — Tablets Nox 400 mg are white to off-white, oval shaped, film-coated tablets, coded 705 on one side and plain on the other. They are supplied as follows:

NDC 0006-0705-20 unit of use bottles of 20. Storage

Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Keep container tightly closed.

Manufactured by: Merck Sharp & Dohme (Italia) S.p. A. Via Emilia, 21 27100 Pavia, Italy. Manufactured for: Merck Sharp & Dohme Corp., a subsidiary of MERCK & CO., INC., Whitehouse Station, NJ 08889, USA. Revised: July 2016

See also:
What is the most important information I should know about Nox?

You should not use Nox if you have a history of myasthenia gravis, or if you are allergic to Nox or similar antibiotics such as ciprofloxacin (Cipro), gemifloxacin (Factive), levofloxacin (Levaquin), moxifloxacin (Avelox), ofloxacin (Nox), and others.

You should not use this medication if you have ever had swelling or tearing of a tendon caused by taking Nox or similar antibiotics.

Before taking Nox, tell your doctor if you have a heart rhythm disorder, kidney or liver disease, muscle weakness or trouble breathing, joint problems, a condition called pseudotumor cerebri, a history of seizures, a history of head injury or brain tumor, low levels of potassium in your blood (hypokalemia), a personal or family history of Long QT syndrome, or if you have ever had an allergic reaction to an antibiotic.

Avoid taking antacids, vitamin or mineral supplements, sucralfate (Carafate), or didanosine (Videx) powder or chewable tablets within 2 hours before or after you take Nox.

Nox may cause swelling or tearing of a tendon (the fiber that connects bones to muscles in the body), especially in the Achilles' tendon of the heel. These effects may be more likely to occur if you are over 60, if you take steroid medication, or if you have had a kidney, heart, or lung transplant. Stop taking Nox and call your doctor at once if you have sudden pain, swelling, tenderness, stiffness, or movement problems in any of your joints. Rest the joint until you receive medical care or instructions.

Use Nox as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Nox comes with an extra patient information sheet called a Medication Guide. Read it carefully. Read it again each time you get Nox refilled.
• Take Nox by mouth on an empty stomach at least 1 hour before or 2 hours after a meal or eating or drinking milk or other dairy products.
• Take Nox with a full glass of water (8 oz/240 mL).
• Drinking extra fluids while you are taking Nox is recommended. Check with your doctor for instructions.
• Do not take any products containing magnesium, aluminum, calcium, iron, or zinc (eg, antacids, quinapril, vitamins/minerals); didanosine; sucralfate; or bismuth subsalicylate within 2 hours before or 2 hours after taking Nox.
• To clear up your infection completely, take Nox for the full course of treatment. Keep taking it even if you feel better in a few days.
• Do not miss any doses. If you miss a dose of Nox, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Nox.

Use: Labeled Indications

Uncomplicated and complicated urinary tract infections caused by susceptible gram-negative and gram-positive bacteria; sexually transmitted disease (eg, uncomplicated urethral and cervical gonorrhea) caused by N. gonorrhoeae; prostatitis due to E. coli

Note: As of April 2007, the CDC no longer recommends the use of fluoroquinolones for the treatment of gonococcal disease.

Limitations of use: Because fluoroquinolones have been associated with disabling and potentially irreversible serious adverse reactions (eg, tendinitis and tendon rupture, peripheral neuropathy, CNS effects), reserve Nox for use in patients who have no alternative treatment options for acute uncomplicated urinary tract infections.

Off Label Uses

Infectious Diarrhea

Based on the Infectious Diseases Society of American (IDSA) Practice Guidelines for the Management of Infectious Diarrhea, Nox given for infectious diarrhea is effective and recommended in the management of this condition.

Spontaneous bacterial peritonitis (prevention)

Data from controlled trials support use of Nox as primary long-term prophylaxis in cirrhotic patients with low protein ascites, or as secondary long-term prophylaxis in patients who have experienced a prior SBP episode. In cirrhotic patients with an active GI bleed, short-term prophylaxis with twice-daily Nox may be used as monotherapy or following initial ceftriaxone therapy. According to AASLD and EASL guidelines, long-term prophylaxis with daily Nox should be considered as secondary prophylaxis in patients who have experienced a prior SBP episode, and as primary prophylaxis in cirrhotic patients with low protein ascites. Twice-daily Nox for short-term prophylaxis (7 days) can be used in cirrhotic patients with GI hemorrhage. Increasing bacterial resistance rates to antibiotics used in the treatment and prevention of SBP have been documented; therefore, local epidemiological patterns should be considered, and use of antibiotic prophylaxis should be restricted to patients at high risk of SBP.

See also:
What other drugs will affect Nox?

Quinolones, including Nox, have been shown in vitro to inhibit CYP1A2. Concomitant use with drugs metabolized by CYP1A2 (e.g., caffeine, clozapine, ropinirole, tacrine, theophylline, tizanidine) may result in increased substrate drug concentrations when given in usual doses. Patients taking any of these drugs concomitantly with Nox should be carefully monitored.

Elevated plasma levels of theophylline have been reported with concomitant quinolone use. There have been reports of theophylline-related side effects in patients on concomitant therapy with Nox and theophylline. Therefore, monitoring of theophylline plasma levels should be considered and dosage of theophylline adjusted as required.

Elevated serum levels of cyclosporine have been reported with concomitant use of cyclosporine with Nox. Therefore, cyclosporine serum levels should be monitored and appropriate cyclosporine dosage adjustments made when these drugs are used concomitantly.

Quinolones, including Nox, may enhance the effects of oral anticoagulants, including warfarin or its derivatives or similar agents. When these products are administered concomitantly, prothrombin time or other suitable coagulation tests should be closely monitored.

The concomitant administration of quinolones including Nox with glyburide (a sulfonylurea agent) has, on rare occasions, resulted in severe hypoglycemia. Therefore, monitoring of blood glucose is recommended when these agents are co-administered.

Diminished urinary excretion of Nox has been reported during the concomitant administration of probenecid and Nox.

The concomitant use of nitrofurantoin is not recommended since nitrofurantoin may antagonize the antibacterial effect of Nox in the urinary tract.

Multivitamins, or other products containing iron or zinc, antacids or sucralfate, should not be administered concomitantly with, or within 2 hours of, the administration of Nox, because they may interfere with absorption resulting in lower serum and urine levels of Nox.

Videx® (Didanosine) chewable/buffered tablets or the pediatric powder for oral solution should not be administered concomitantly with, or within 2 hours of, the administration of Nox, because these products may interfere with absorption resulting in lower serum and urine levels of Nox.

Some quinolones have also been shown to interfere with the metabolism of caffeine. This may lead to reduced clearance of caffeine and a prolongation of the plasma half-life that may lead to accumulation of caffeine in plasma when products containing caffeine are consumed while taking Nox.

The concomitant administration of a non-steroidal anti-inflammatory drug (NSAID) with a quinolone, including Nox, may increase the risk of CNS stimulation and convulsive seizures. Therefore, Nox should be used with caution in individuals receiving NSAIDS concomitantly.

See also:
What are the possible side effects of Nox?

Applies to Nox: oral tablet

As well as its needed effects, Nox (the active ingredient contained in Nox) may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking Nox, check with your doctor immediately:

Rare

• Chest pain or discomfort
• chills
• diarrhea
• discouragement
• fast, irregular, pounding, or racing heartbeat or pulse
• feeling sad or empty
• fever
• flushing or redness of the skin
• hives or welts
• increased sweating
• irritability
• irritation or soreness of the mouth
• itching of the rectal area
• itching skin
• lack of appetite
• loss of interest or pleasure
• nausea
• pain and inflammation at the joints
• pain or discomfort in the arms, jaw, back, or neck
• redness of the skin
• shortness of breath
• skin rash
• sweating
• swelling of the foot or hand
• swelling of the stomach
• tingling of the fingers
• tiredness
• trouble with concentrating
• trouble with sleeping
• unusually warm skin
• vomiting

• Abdominal or stomach cramps or tenderness
• anxiety
• back, leg, or stomach pains
• black, tarry stools
• bleeding gums
• blistering, peeling, or loosening of the skin
• bloating
• blood in the urine or stools
• blurred vision
• bone pain
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• clay-colored stools
• cold sweats
• constipation
• cool, pale skin
• cough or hoarseness
• cracks in the skin
• dark-colored urine
• decreased frequency or amount of urine
• diarrhea, watery and severe, which may also be bloody
• difficulty with breathing, chewing, swallowing, or talking
• difficulty with moving
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• double vision
• drooping eyelids
• dry mouth
• dry skin
• false sense of well-being
• fever with or without chills
• fruit-like breath odor
• general body swelling
• general feeling of tiredness or weakness
• greatly decreased frequency of urination or amount of urine
• headache
• inability to move the arms and legs
• increased blood pressure
• increased hunger
• increased sensitivity of the skin to sunlight
• increased thirst
• increased urination
• indigestion
• irregular or slow heart rate
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• light-colored stools
• loss of heat from the body
• lower back or side pain
• mood or mental changes
• mood swings
• muscle aching or cramping
• muscle pain or stiffness
• muscle weakness
• nervousness
• nightmares
• nosebleeds
• numbness or tingling in the hands, feet, or lips
• pain or burning while urinating
• pain, inflammation, or swelling in the calves, shoulders, or hands
• pain, swelling, or redness in the joints
• painful or difficult urination
• pains in the stomach, side, or abdomen, possibly radiating to the back
• personality changes
• pinpoint red spots on the skin
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• red skin lesions, often with a purple center
• red, irritated eyes
• red, swollen skin
• scaly skin
• seizures
• severe sunburn
• severe tiredness
• shakiness and unsteady walk
• skin rash
• slurred speech
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• sores, welting, or blisters
• stomach pain, continuing
• sudden decrease in the amount of urine
• sudden numbness and weakness in the arms and legs
• swelling of the face, fingers, or lower legs
• swelling or inflammation of the mouth
• swollen glands
• tightness in the chest
• unexplained weight loss
• unpleasant breath odor
• unsteadiness, awkwardness, trembling, or other problems with muscle control or coordination
• unusual behavior, such as disorientation to time or place, failure to recognize people, hyperactivity, or restlessness
• unusual bleeding or bruising
• unusual tiredness or weakness
• unusual weight loss
• vomiting of blood
• weakness in the arms, hands, legs, or feet
• weight gain
• wheezing
• yellowing of the eyes or skin

Minor Side Effects

Some Nox side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

Less common:

• Lack or loss of strength

• Acid or sour stomach
• belching
• bitter taste
• cramps
• excess air or gas in the stomach or intestines
• full feeling
• heartburn
• heavy bleeding
• pain
• passing gas
• sleepiness or unusual drowsiness
• sleeplessness
• stomach discomfort, upset, or pain
• unable to sleep
• weight loss

• Change in taste
• continuing ringing or buzzing or other unexplained noise in the ears
• hearing loss
• itching of the vagina or outside genitals
• loss of taste
• pain during sexual intercourse
• seeing double
• thick, white curd-like vaginal discharge without odor or with mild odor
• uncontrolled eye movements