Quinolones, including moxifloxacin have the risk of exacerbation of symptoms of myasthenia gravis, and patients with myasthenia gravis should avoid using the product.
In some instances, the hypersensitivity and allergic reactions already occurred after the first administration and the doctor should be informed immediately.
Anaphylactic reactions in very rare instances can progress to a life-threatening shock, in some instances after the first administration. In these cases the treatment with moxifloxacin has to be discontinued, medical treatment (e.g. treatment for shock) is required.
Moxifloxacin has been shown to prolong the QT interval of the electrocardiogram in some patients. As women tend to have a longer baseline QTc interval compared with men, they may be more sensitive to QTc-prolongation medications. Elderly patients may also be more susceptible to drug-associated effects on the QT interval.
As the magnitude of QT prolongation may increase with increasing concentrations of the drug, the recommended dose and the infusion rate (400 mg within 60 minutes) should not be exceeded. However, in patients suffering from pneumonia no correlation between plasma concentrations of moxifloxacin and QTc prolongation was observed. QT prolongation may lead to an increased risk for ventricular arrhythmias including torsades de pointes.
No cardiovascular morbidity or mortality attributable to QTc prolongation occurred with Moxifloxacin treatment in clinical studies with more than 9,000 patients; however certain predisposing conditions may increase the risk for ventricular arrhythmias.
Therefore, treatment with Moxifloxacin should be avoided due to the lack of clinical experience with the drug in these patient populations: in patients with known prolongation of the QTc interval; in patients with uncorrected hypokalemia; in patients receiving class IA (e.g. quinidine, procainamide) or class III (e.g. amiodarone, sotalol) antiarrhythmic agents.
Moxifloxacin should be used with caution as an additive effect of moxifloxacin on the QTc interval cannot be excluded for the following conditions: in patients treated concomitantly with drugs that prolong the QTc interval such as cisapride, erythromycin, antipsychotics, and tricyclic antidepressants; in patients with ongoing proarrhythmic conditions, such as clinically significant bradycardia, acute myocardial ischemia; in patients with liver cirrhosis as pre-existing QTc prolongation in these patients cannot be excluded; in women and elderly patients who, both, may be more susceptible to QTc-prolonging drugs.
Cases of fulminant hepatitis potentially leading to liver failure (including fatal cases) have been reported with Moxifloxacin (see Adverse Reactions). Patients should be advised to contact their doctor immediately prior to continuing treatment if symptoms related to liver failure occur.
Cases of bullous skin reactions like Stevens-Johnson syndrome or toxic epidermal necrolysis have been reported with Moxifloxacin (see Adverse Reactions). Patients should be advised to contact their doctor immediately prior to continuing treatment if skin and/or mucosal reactions occur.
Seizures may occur with quinolone therapy. It should be used with caution in patients with known or suspected CNS disorders which may predispose to seizures or lower the seizure threshold.
Antibiotics associated colitis has been reported with the use of broad-spectrum antibiotics including moxifloxacin, therefore it is important to consider this diagnosis in patients who develop serious diarrhea in association with the use of moxifloxacin. In this clinical situation adequate therapeutic measures should be initiated immediately. Drugs-induced inhibition of peristalsis are contraindicated in patients who develop serious diarrhea.
Moxifloxacin should be used with caution in patients with myasthenia gravis because the symptoms can be exacerbated.
Tendon inflammation and rupture may occur with quinolone therapy including moxifloxacin, particularly in elderly patients and in those treated concurrently with corticosteroids; cases occurring up to several months after completion of therapy have been reported. At the first sign of pain or inflammation, patients should discontinue treatment and rest the affected limb(s).
For patients with complicated pelvic inflammatory disease (e.g. associated with a tubo-ovarian or pelvic abscess), for whom an intravenous treatment is considered necessary, treatment with Moxifloxacin 400 mg film-coated tablets is not recommended.
Moxifloxacin is not recommended for the treatment of MRSA infections. In case of a suspected or confirmed infection due to MRSA, treatment with an appropriate antibacterial agent should be started (see Pharmacology: Pharmacodynamics under Actions).
Moxifloxacin in vitro activity may interfere with the Mycobacterium spp. culture test by suppression of mycobacterial growth, causing false negative results in specimens from patients currently taking Moxifloxacin.
Cases of sensory or sensorimotor polyneuropathy resulting in paraesthesias, hypoaesthesias, dysaesthesias, or weakness have been reported in patients receiving quinolones including Moxifloxacin. Patients under treatment with Moxifloxacin should be advised to inform their doctor prior to continuing treatment if symptoms of neuropathy such as pain, burning, tingling,numbness, or weakness develop (see Adverse Reactions).
Psychiatric reactions may occur even after the first administration of fluoroquinolones, including moxifloxacin. In very rare cases depression or psychotic reactions have progressed to suicidal thoughts and self-injurious behavior such as suicide attempts (see Adverse Reactions).
In the event that the patient develops these reactions, Moxifloxacin should be discontinued and appropriate measures instituted. Caution is recommended if Moxifloxacin is to be used in psychotic patients or in patients with a history of psychiatric disease.
Because of the widespread and rising prevalence of fluoroquinolone resistant Neisseria gonorrhoeae infections, monotherapy with moxifloxacin should be avoided in patients with pelvic inflammatory disease, unless fluoroquinolone-resistant N. gonorrhoeae can be excluded.
If fluoroquinolone-resistant N. gonorrhoeae cannot be excluded, the addition of an appropriate antibiotic which is regularly active against N. gonorrhoeae (e.g., a cephalosporin) to empirical moxifloxacin therapy, should be considered.
Information about excipients: In patients for whom sodium intake is of medical concern (patients with congestive heart failure, renal failure, nephrotic syndrome, etc.) the additional sodium load of the solution for infusion should be taken into account. For sodium chloride content of the solution for infusion see Description.
Effects on Ability to Drive and Use Machines: Fluoroquinolones including moxifloxacin may result in an impairment of the patient's ability to drive or operate machinery due to CNS reactions (see Adverse Reactions).