Azithromycin (Zithromax)
Zithromax is a macrolide antibacterial drug indicated for the treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions. Zithromax (azithromycin tablets and oral suspension) contains the active ingredient azithromycin, a macrolide antibacterial drug, for oral administration. Zithromax tablets contain azithromycin dihydrate equivalent to 500mg azithromycin. They also contain the following inactive ingredients: dibasic calcium phosphate anhydrous, pregelatinized starch, sodium croscarmellose, magnesium stearate, sodium lauryl sulfate, and an aqueous film coat consisting of hypromellose, titanium dioxide, lactose, and triacetin. Zithromax for oral suspension is supplied in a single-dose packet containing azithromycin dihydrate equivalent to 1 g azithromycin. It also contains the following inactive ingredients: colloidal silicon dioxide, sodium phosphate tribasic, anhydrous; spray dried artificial banana flavor, spray dried artificial cherry flavor, and sucrose. To reduce the development of drug-resistant bacteria and maintain the effectiveness of Zithromax and other antibacterial drugs, Zithromax 600mg should be used only to treat 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.
Zithromax is one of the world's best-selling antibiotics. Buying Azithromycin you can use it to treat or prevent certain bacterial infections, most often those causing middle ear infections, strep throat, pneumonia, typhoid, bronchitis and sinusitis. In recent years, it has been used primarily to prevent bacterial infections in infants and those with weaker immune systems.
The invention of Zithromax, the active pharmaceutical ingredient of this antibiotic belongs among the great achievements in the history of science. From the viewpoint of commercialization of research results, it may have been one of the greatest.
Zithromax can be considered as the first and foremost example of successful knowledge and technology transfer ever.
Zithromax Dosage And Administration
Zithromax can be taken with or without food after constitution. However, increased tolerability has been observed when tablets are taken with food.
Sexually Transmitted Diseases
If a chlamydia infection goes unnoticed, it can spread and cause complications. Most commonly, it spreads from the cervix to the fallopian tubes, resulting in bleeding or pain during sex. Further possible symptoms include unusual bleeding and spotting, nausea and fever as well as abdominal and lower back pain. The recommended dose of Zithromax for the treatment of non-gonococcal urethritis and cervicitis due to C. trachomatis is a single 1 gram (1000 mg) dose of Zithromax. This dose can be administered as one single dose.
Mycobacterial Infections
The recommended dose of Zithromax for the prevention of disseminated Mycobacterium avium complex (MAC) disease is: 1200 mg taken once weekly.
Treatment of Disseminated MAC Infections
Zithromax should be taken at a daily dose of generic 500mg or brand 600mg, in combination with ethambutol at the recommended daily dose of 15 mg/kg. Other antimycobacterial drugs may be added to the regimen of azithromycin at the discretion of the physician or health care provider.
If you want to order delivery of Zithromax pills cheaper, but it is very expensive at local drugstores, you can buy it on any of trusted online pharmacies.
What the difference between Sumamed and Zithromax?
The difference between Sumamed and Zithromax is different manufacturers. You can buy generic zithromax tablets online and get a discount if you order a large package of pills or when placing your second and following orders. Online pharmacies also offer free shipping for large orders and bonus pills, some of them have an overnight delivery option as well. When buying online you often can get a discount. This will compensate your postal expenses.
Other facts
Azithromycin demonstrates cross-resistance with erythromycin-resistant Gram-positive strains, including Streptococcus faecalis (Enterococcus) and to most strains of methicillin-resistant Staphylococci. The invention was due to the scientists from the Research Institute of the pharmaceutical company PLIVA. Azithromycin became the first representative of the new class of 15-membered macrolides known as azalides after the introduction of nitrogen in the macrocycle of erythromycin A. Its synthesis involved several steps: oximation of erithromycin A, Beckmann rearrangement of erythromycin A oxime with aromatic sulphochlorides, reduction of the produced erithromycin A iminoether, and final methylation of the nitrogen introduced in the macrocycle of erythromycin A. Because of inadequate analytical support in the late 1970s and early 1980s, the precise structure of the LD product in the Beckmann rearrangement step of azithromycin synthesis was confirmed only later as 7 and not 6 as assumed.
Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to azithromycin. Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of infection after you finish the azithromycin, call your doctor. It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Interaction with other medical products
Antacids: In a pharmacokinetic study investigating the effects of simultaneous administration of antacid with azithromycin, no effect on overall bioavailability was seen, although peak serum concentrations were reduced by approximately 24%. In patients receiving both azithromycin and antacids, the drugs should not be taken simultaneously.
Cetirizine: In healthy volunteers, co-administration of a 5-day regimen of azithromycin with 20 mg cetirizine at steady-state resulted in no pharmacokinetic interaction and no significant changes in the QT interval.
Didanosine (Dideoxyinosine): Co-administration of 1200 mg/day azithromycin with 400 mg/day didanosine in six HIV-positive subjects did not appear to affect the steady-state pharmacokinetics of didanosine as compared to placebo.
Digoxin and colchicine: concomitant administration of macrolide antibiotics, including azithromycin, with P-glycoprotein substrates such as digoxin and colchicine, has been reported to result in increased serum levels of the P-glycoprotein substrate. Therefore, if azithromycin and P-glycoprotein substrates such as digoxin are administered concomitantly, the possibility of elevated serum digoxin concentrations should be considered. Clinical monitoring, and possibly serum digoxin levels, during treatment with azithromycin and after its discontinuation are necessary.
Zidovudine: Single 1000 mg doses and multiple 1200 mg or 600 mg doses of azithromycin had little effect on the plasma pharmacokinetics or urinary excretion of zidovudine or its glucuronide metabolite. However, administration of azithromycin increased the concentrations of phosphorylated zidovudine, the clinically active metabolite, in peripheral blood mononuclear cells. The clinical significance of this finding is unclear, but it may be of benefit to patients.
Azithromycin does not interact significantly with the hepatic cytochrome P450 system. It is not believed to undergo the pharmacokinetic drug interactions as seen with erythromycin and other macrolides. Hepatic cytochrome P450 induction or inactivation via cytochrome-metabolite complex does not occur with azithromycin.
Ergot derivatives: Due to the theoretical possibility of ergotism, the concurrent use of azithromycin with ergot derivatives is not recommended.
Pharmacokinetic studies have been conducted between azithromycin and the following drugs known to undergo significant cytochrome P450 mediated metabolism.
Atorvastatin: Co-administration of atorvastatin (10 mg daily) and azithromycin (500 mg daily) did not alter the plasma concentrations of atorvastatin (based on a HMG CoA-reductase inhibition assay).
Carbamazepine: In a pharmacokinetic interaction study in healthy volunteers, no significant effect was observed on the plasma levels of carbamazepine or its active metabolite in patients receiving concomitant azithromycin.
Cimetidine: In a pharmacokinetic study investigating the effects of a single dose of cimetidine, given 2 hours before azithromycin, on the pharmacokinetics of azithromycin, no alteration of azithromycin pharmacokinetics was seen.
Coumarin-type oral anticoagulants: In a pharmacokinetic interaction study, azithromycin did not alter the anticoagulant effect of a single dose of 15 mg warfarin administered to healthy volunteers. There have been reports received in the post-marketing period of potentiated anticoagulation subsequent to co-administration of azithromycin and coumarin-type oral anticoagulants. Although a causal relationship has not been established, consideration should be given to the frequency of monitoring prothrombin time when azithromycin is used in patients receiving coumarin-type oral anticoagulants.
Efavirenz: Co-administration of a single dose of 600 mg azithromycin and 400 mg efavirenz daily for 7 days did not result in any clinically significant pharmacokinetic interactions.
Fluconazole: Co-administration of a single dose of 1200 mg azithromycin did not alter the pharmacokinetics of a single dose of 800 mg fluconazole. Total exposure and half-life of azithromycin were unchanged by the co-administration of fluconazole, however, a clinically insignificant decrease in (18%) of azithromycin was observed.
Indinavir: Co-administration of a single dose of 1200 mg azithromycin had no statistically significant effect on the pharmacokinetics of indinavir administered as 800 mg three times daily for 5 days.
Methylprednisolone: In a pharmacokinetic interaction study in healthy volunteers, azithromycin had no significant effect on the pharmacokinetics of methylprednisolone.
Midazolam: In healthy volunteers, co-administration of 500mg/day azithromycin for 3 days did not cause clinically significant changes in the pharmacokinetics and pharmacodynamics of a single dose of 15mg midazolam.
Nelfinavir: Co-administration of azithromycin (1200 mg) and nelfinavir at steady state (750 mg three times daily) resulted in increased azithromycin concentrations. No clinically significant adverse effects were observed and no dose adjustment was required.
Rifabutin: Co-administration of azithromycin and rifabutin did not affect the serum concentrations of either drug. Neutropenia was observed in subjects receiving concomitant treatment of azithromycin and rifabutin. Although neutropenia has been associated with the use of rifabutin, a causal relationship to combination with azithromycin has not been established.
Terfenadine: Pharmacokinetic studies have reported no evidence of an interaction between azithromycin and terfenadine. There have been rare cases reported where the possibility of such an interaction could not be entirely excluded; however there was no specific evidence that such an interaction had occurred.
Theophylline: There is no evidence of a clinically significant pharmacokinetic interaction when azithromycin and theophylline are co-administered to healthy volunteers.
Triazolam: In 14 healthy volunteers, co-administration of 500mg azithromycin on Day 1 and 250 mg on Day 2 with 0.125 mg triazolam on Day 2 had no significant effect on any of the pharmacokinetic variables for triazolam compared to triazolam and placebo.
Trimethoprim/sulfamethoxazole: Co-administration of trimethoprim/sulfamethoxazole DS (160 mg/800 mg) for 7 days with 1200mg azithromycin on Day 7 had no significant effect on peak concentrations, total exposure or urinary excretion of either trimethoprim or sulfamethoxazole. Azithromycin serum concentrations were similar to those seen in other studies.
Side Effects
Zithromax is used to treat many different types of infections caused by bacteria, such as respiratory infections, skin infections, ear infections. Side effects, drug interactions, and warnings and precautions should be reviewed prior to taking this medication.
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In clinical trials, most of the reported adverse reactions were mild to moderate in severity and were reversible upon discontinuation of the drug. Approximately 0.7% of the patients from the multiple-dose clinical trials discontinued Zithromax (azithromycin) therapy because of treatment-related adverse reactions. Serious adverse reactions included angioedema and cholestatic jaundice. Most of the adverse reactions leading to discontinuation were related to the gastrointestinal tract, e.g., nausea, vomiting, diarrhea, or abdominal pain.
Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, stop taking this medicine and call your doctor. Other drugs may interact with azithromycin, including prescription and over-the-counter medicines, vitamins, and herbal products.
How to use
Do not take Zithromax if you are allergic to:
- Azithromycin or any other macrolide or ketolide antibiotics (e.g. clarithromycin, erythromycin, roxithromycin, telithromycin)
- Any of the ingredients listed here.
Symptoms of an allergic reaction may include shortness of breath, wheezing or difficulty breathing swelling of the face, lips, tongue or other parts of the body rash, itching or hives on the skin.
Do not take this medicine if the expiry date (EXP) printed on the packaging has passed or if the packaging is torn or shows signs of tampering. If it has expired or is damaged, return it to your pharmacist for disposal.
If you are not sure whether you should start taking this medicine, talk to your doctor.
Tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin, Jantoven); colchicine (Colcrys, Gloperba); cyclosporine (Neoral, Sandimmune); digoxin (Lanoxin); dihydroergotamine (D.H.E. 45, Migranal); ergotamine (Ergomar); medications for irregular heartbeat such as amiodarone (Cordarone, Pacerone), dofetilide (Tikosyn), procainamide (Procanbid), quinidine, and sotalol (Betapace, Sorine); nelfinavir (Viracept); phenytoin (Dilantin); and terfenadine (not available in the U.S.). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. If you are taking antacids containing aluminum hydroxide or magnesium hydroxide (Maalox, Mylanta, Tums, others), you will need to allow some time to pass between when you take a dose of these antacids and when you take a dose of azithromycin tablets or liquid. Ask your doctor or pharmacist how many hours before or after you take azithromycin you may take these medications. The extended-release suspension may be taken at any time with antacids. Tell your pharmacist if you have ever had jaundice (yellowing of the skin or eyes) or other liver problems while taking azithromycin. Your doctor will probably tell you not to take azithromycin. Tell your pharmacist if you or anyone in your family has or has ever had a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death) or a fast, slow, or irregular heartbeat, and if you have low levels of magnesium or potassium in your blood; if you have a blood infection; heart failure; cystic fibrosis; myasthenia gravis (a condition of muscles and the nerves that control them); or if you have kidney or liver disease. Tell your pharmacist if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking azithromycin, call your doctor.
Tell your doctor if you have allergies to any other medicines, foods, preservatives or dyes before you start to take it. Tell your doctor if you have any other health problems, including:
- Any liver problems
- Any kidney problems
- Any heart problems, including abnormalities of the rhythm
- Diabetes, hereditary fructose intolerance, glucose-galactose malabsorption or sacchariseisomaltase deficiency
- Cystic fibrosis
- Muscle weakness
- Low levels of potassium or magnesium in your blood
- If you are pregnant or if you plan to become pregnant or are breastfeeding. Your doctor can discuss with you the risks and benefits involved.
If you have not told your doctor about any of the above, tell them before you start taking Zithromax.
How to store
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. Keep Zithromax in the container it came in, tightly closed, and out of reach of children. Store azithromycin tablets, suspension, and extended-release suspension at room temperature and away from excess heat and moisture. Unneeded Zithromax pills should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage or recycling department to learn about take-back programs in your community.