Moxifloxacin Hydrochloride (Page 7 of 14)

7 DRUG INTERACTIONS

7.1 Antacids, Sucralfate, Multivitamins and other Products Containing Multivalent Cations

Fluoroquinolones, including Moxifloxacin Tablets, form chelates with alkaline earth and transition metal cations. Oral administration of Moxifloxacin Tablets with antacids containing aluminum or magnesium, with sucralfate, with metal cations such as iron, or with multivitamins containing iron or zinc, or with formulations containing divalent and trivalent cations such as didanosine buffered tablets for oral suspension or the pediatric powder for oral solution, may substantially interfere with the absorption of moxifloxacin, resulting in systemic concentrations considerably lower than desired. Therefore, Moxifloxacin Tablets should be taken at least 4 hours before or 8 hours after these agents [see Dosage and Administration (2.2) and Clinical Pharmacology (12.3)].

7.2 Warfarin

Fluoroquinolones, including Moxifloxacin Tablets, have been reported to enhance the anticoagulant effects of warfarin or its derivatives in the patient population. In addition, infectious disease and its accompanying inflammatory process, age, and general status of the patient are risk factors for increased anticoagulant activity. Therefore the prothrombin time, International Normalized Ratio (INR), or other suitable anticoagulation tests should be closely monitored if Moxifloxacin Tablets are administered concomitantly with warfarin or its derivatives [see Adverse Reactions (6.2) and Clinical Pharmacology (12.3)].

7.3 Antidiabetic Agents

Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with fluoroquinolones, including moxifloxacin, and an antidiabetic agent. Therefore, careful monitoring of blood glucose is recommended when these agents are co-administered. If a hypoglycemic reaction occurs, Moxifloxacin Tablets should be discontinued and appropriate therapy should be initiated immediately [see Warnings and Precautions (5.12) and Adverse Reactions (6.1)].

7.4 Nonsteroidal Anti-Inflammatory Drugs

The concomitant administration of a nonsteroidal anti-inflammatory drug (NSAID) with a fluoroquinolone, including Moxifloxacin Tablets, may increase the risks of CNS stimulation and convulsions [see Warnings and Precautions (5.4)].

7.5 Drugs that Prolong QT

There is limited information available on the potential for a pharmacodynamic interaction in humans between moxifloxacin and other drugs that prolong the QTc interval of the electrocardiogram. Sotalol, a Class III antiarrhythmic, has been shown to further increase the QTc interval when combined with high doses of intravenous moxifloxacin in dogs. Therefore, Moxifloxacin Tablets should be avoided with Class IA and Class III antiarrhythmics [see Warnings and Precautions, (5.6) and Nonclinical Toxicology (13.2)].

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Risk Summary

There are no available human data establishing a drug associated risk with the use of moxifloxacin.

Based on animal studies with moxifloxacin, Moxifloxacin Tablets may cause fetal harm. Moxifloxacin did not cause fetal malformations when administered to pregnant rats (IV and oral), rabbits (IV), and monkeys (oral) at exposures that were 0.24–2.5 times of those at the human clinical dose (400 mg/day moxifloxacin). However, when moxifloxacin was administered to rats and rabbits during pregnancy and throughout lactation (rats only) at doses associated with maternal toxicity, decreased neonatal body weights, increased incidence of skeletal variations (rib and vertebra combined), and increased fetal loss were observed ( see Data). Advise pregnant women of the potential risk to the fetus.

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Data

Animal Data

Animal reproductive and development studies were done in rats, rabbits and cynomolgus macaques. Moxifloxacin did not cause fetal malformations when administered to pregnant rats during organogenesis (gestation days 6 to 17) at oral doses as high as 500 mg/kg/day or 0.24 times the maximum recommended human dose based on systemic exposure (AUC), but decreased fetal body weights and slightly delayed fetal skeletal development were observed. Intravenous administration of 80 mg/kg/day (approximately 2 times the maximum recommended human dose based on body surface area) to pregnant rats resulted in maternal toxicity and a marginal effect on fetal and placental weights and the appearance of the placenta (Gestation days 6 to 17). Fetal malformations were not observed at intravenous doses as high as 80 mg/kg/day (approximately 2 times the maximum recommended human dose based on body surface area) in litters of pregnant rats that received moxifloxacin during organogenesis (Gestation days 6 to 17). Intravenous administration of 20 mg/kg/day (approximately equal to the maximum recommended human oral dose based upon systemic exposure) to pregnant rabbits during organogenesis (gestation days 6 to 20) resulted in decreased fetal body weights and delayed fetal skeletal ossification. When rib and vertebral malformations were combined, there was an increased fetal and litter incidence of these effects in rabbits. Signs of maternal toxicity in rabbits at this dose included mortality, abortions, marked reduction of food consumption, decreased water intake, body weight loss and hypoactivity. Fetal malformations were not observed when pregnant cynomolgus macaques were given oral doses as high as 100 mg/kg/day (2.5 times the maximum recommended human dose based upon systemic exposure) during organogenesis (gestation days 20 to 50). An increased incidence of smaller fetuses was observed at 100 mg/kg/day in macaques. In a pre-and postnatal development study conducted in rats given oral doses from Gestation day 6, throughout gestation and rearing to Postpartum day 21, effects observed at 500 mg/kg/day (0.24 times the maximum recommended human dose based on systemic exposure (AUC)) included slight increases in duration of pregnancy and prenatal loss, reduced pup birth weight and decreased neonatal survival. Treatment-related maternal mortality occurred during gestation at 500 mg/kg/day in this study.

8.2 Lactation

Risk Summary

It is not known if moxifloxacin is present in human milk. Based on animal studies in rats, moxifloxacin may be excreted in human milk ( see Data). When a drug is present in animal milk, it is likely that the drug will be present in human milk.

The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Moxifloxacin Tablets and any potential adverse effects on the breastfed child from Moxifloxacin Tablets or from the underlying maternal condition.

Data

In lactating rats given a single oral dose of 4.59 mg/kg moxifloxacin (approximately 9 times less than the recommended human dose based on body surface area) 8 days postpartum, there was very low excretion of substance-related radioactivity into the milk, amounting to approximately 0.03% of the dose.