Cheap Zithromax

What is Zithromax?

* Zithromax is in a group of drugs called macrolide antibiotics. Zithromax fights bacteria in the body.
* Zithromax is used to treat many different types of infections caused by bacteria, such as respiratory infections, skin infections, ear infections, and sexually transmitted diseases.
* Zithromax may also be used for purposes other than those listed in this medication guide.

Zithromax is used for:

Treating infections caused by certain bacteria. Zithromax will not work for colds, flu, or other viral infections. It may also be used for other conditions as determined by your doctor.

Zithromax is a macrolide antibiotic. It slows the growth of, or sometimes kills, sensitive bacteria by reducing the production of important proteins needed by the bacteria to survive.

Mechanism of Action

Zithromax acts by binding to the 50S ribosomal subunit of susceptible microorganisms and, thus, interfering with microbial protein synthesis. Nucleic acid synthesis is not affected.

Zithromax concentrates in phagocytes and fibroblasts as demonstrated by in vitro incubation techniques. Using such methodology, the ratio of intracellular to extracellular concentration was >30 after one hour incubation. In vivo studies suggest that concentration in phagocytes may contribute to drug distribution to inflamed tissues.

How should I take Zithromax?

* Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. The dose and length of treatment with Zithromax may not be the same for every type of infection.
* Zithromax capsules must be taken on an empty stomach with a full glass (8 ounces) of water. Take the capsule at least 1 hour before or 2 hours after eating a meal.
* Zithromax tablets or powder oral suspension may be taken with or without food. Take the tablet or oral suspension with food if the medicine upsets your stomach.
* Do not take Zithromax at the same time as taking an antacid that contains aluminum or magnesium. This includes Rolaids, Maalox, Mylanta, Milk of Magnesia, Pepcid Complete, and others. These antacids can make Zithromax less effective when taken at the same time.
* It is important to take Zithromax regularly to get the most benefit.
* Store this medication at room temperature away from moisture and heat. Throw away any unused liquid medicine after 10 days.

Drug Interactions

Aluminum- and magnesium-containing antacids reduce the peak serum levels (rate) but not the AUC (extent) of Zithromax (500 mg) absorption.

Administration of cimetidine (800 mg) two hours prior to Zithromax had no effect on Zithromax (500 mg) absorption.

A single oral dose of 1200 mg Zithromax (2 × 600 mg Zithromax tablets) did not alter the pharmacokinetics of a single 800 mg oral dose of fluconazole in healthy adult subjects.

Total exposure (AUC) and half-life of Zithromax following the single oral tablet dose of 1200 mg were unchanged and the reduction in Cmax was not significant (mean decrease of 18%) by coadministration with 800 mg fluconazole.

A single oral dose of 1200 mg Zithromax (2 × 600 mg Zithromax tablets) had no significant effect on the pharmacokinetics of indinavir (800 mg indinavir tid for 5 days) in healthy adult subjects.

Coadministration of a single oral dose of 1200 mg Zithromax (2 × 600 mg Zithromax tablets) with steady-state nelfinavir (750 mg tid) to healthy adult subjects produced a decrease of approximately 15% in mean AUC0–8 of nelfinavir and its M8 metabolite. Mean Cmax of nelfinavir and its M8 metabolite were not significantly affected. No dosage adjustment of nelfinavir is required when nelfinavir is coadministered with Zithromax.

Coadministration of nelfinavir (750 mg tid) at steady state with a single oral dose of 1200 mg Zithromax increased the mean AUC0–∞ of Zithromax by approximately a factor of 2-times (range of up to 4 times) of that when Zithromax was given alone. The mean Cmax of Zithromax was also increased by approximately a factor of 2-times (range of up to 5 times) of that when Zithromax was given alone. Dose adjustment of Zithromax is not recommended. However, when administered in conjunction with nelfinavir, close monitoring for known side effects of Zithromax, such as liver enzyme abnormalities and hearing impairment, is warranted. (See ADVERSE REACTIONS.)

Following administration of trimethoprim/sulfamethoxazole DS (160 mg/800 mg) for 7 days to healthy adult subjects, coadministration of 1200 mg Zithromax (2 × 600 mg Zithromax tablets) on the 7th day had no significant effects on peak concentrations (Cmax), total exposure (AUC), and the urinary excretion of either trimethoprim or sulfamethoxazole.

Coadministration of trimethoprim/sulfamethoxazole DS for 7 days had no significant effect on the peak concentration (Cmax) and total exposure (AUC) of Zithromax following administration of the single 1200 mg tablet dose to healthy adult subjects.

Administration of a 600 mg single oral dose of Zithromax had no effect on the pharmacokinetics of efavirenz given at 400 mg doses for 7 days to healthy adult subjects.

Efavirenz, when administered at a dose of 400 mg for seven days produced a 22% increase in the Cmax of Zithromax administered as a 600 mg single oral dose, while the AUC of Zithromax was not affected.

Zithromax (500 mg Day 1, 250 mg Days 2–5) did not affect the plasma levels or pharmacokinetics of theophylline administered as a single intravenous dose. The effect of Zithromax on the plasma levels or pharmacokinetics of theophylline administered in multiple doses resulting in therapeutic steady-state levels of theophylline is not known. However, concurrent use of macrolides and theophylline has been associated with increases in the serum concentrations of theophylline. Therefore, until further data are available, prudent medical practice dictates careful monitoring of plasma theophylline levels in patients receiving Zithromax and theophylline concomitantly.

Zithromax (500 mg Day 1, 250 mg Days 2–5) did not affect the prothrombin time response to a single dose of warfarin. However, prudent medical practice dictates careful monitoring of prothrombin time in all patients treated with Zithromax and warfarin concomitantly. Concurrent use of macrolides and warfarin in clinical practice has been associated with increased anticoagulant effects.

Dose adjustments are not indicated when Zithromax and zidovudine are coadministered. When zidovudine (100 mg q3h ×5) was coadministered with daily Zithromax (600 mg, n=5 or 1200 mg, n=7), mean Cmax, AUC and Clr increased by 26% (CV 54%), 10% (CV 26%) and 38% (CV 114%), respectively. The mean AUC of phosphorylated zidovudine increased by 75% (CV 95%), while zidovudine glucuronide Cmax and AUC increased by less than 10%. In another study, addition of 1 gram Zithromax per week to a regimen of 10 mg/kg daily zidovudine resulted in 25% (CV 70%) and 13% (CV 37%) increases in zidovudine Cmax and AUC, respectively. Zidovudine glucuronide mean Cmax and AUC increased by 16% (CV 61%) and 8.0% (CV 32%), respectively.

Doses of 1200 mg/day Zithromax for 14 days in 6 subjects increased Cmax of concurrently administered didanosine (200 mg q.12h) by 44% (54% CV) and AUC by 14% (23% CV). However, none of these changes were significantly different from those produced in a parallel placebo control group of subjects.

Preliminary data suggest that coadministration of Zithromax and rifabutin did not markedly affect the mean serum concentrations of either drug. Administration of 250 mg Zithromax daily for 10 days (500 mg on the first day) produced mean concentrations of Zithromax 1 day after the last dose of 53 ng/mL when coadministered with 300 mg daily rifabutin and 49 mg/mL when coadministered with placebo. Mean concentrations 5 days after the last dose were 23 ng/mL and 21 ng/mL in the two groups of subjects. Administration of 300 mg rifabutin for 10 days produced mean concentrations of rifabutin one half day after the last dose of 60 mg/ml when coadministered with daily 250 mg Zithromax and 71 ng/mL when coadministered with placebo. Mean concentrations 5 days after the last dose were 8.1 ng/mL and 9.2 ng/mL in the two groups of subjects.

The following drug interactions have not been reported in clinical trials with Zithromax; however, no specific drug interaction studies have been performed to evaluate potential drug-drug interaction. Nonetheless, they have been observed with macrolide products. Until further data are developed regarding drug interactions when Zithromax and these drugs are used concomitantly, careful monitoring of patients is advised:

Digoxin–elevated digoxin levels.

Ergotamine or dihydroergotamine–acute ergot toxicity characterized by severe peripheral vasospasm and dysesthesia.

Triazolam–decrease the clearance of triazolam and thus may increase the pharmacologic effect of triazolam.

Drugs metabolized by the cytochrome P450 system–elevations of serum carbamazepine, cyclosporine, hexobarbital, and phenytoin levels.

What are the possible side effects of Zithromax?

* Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
* Stop using Zithromax and call your doctor at once if you have any of these serious side effects:
o diarrhea that is watery or bloody;
o chest pain, uneven heartbeats; or
o nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
* Continue using Zithromax and talk with your doctor if you have any of these less serious side effects:
o mild nausea, vomiting, diarrhea, constipation, or stomach pain;
o dizziness, tired feeling, or headache;
o vaginal itching or discharge; or
o mild itching or skin rash.
* Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.