Azithromycin (Zithromax) 250mg, 500mg, 1000mg

Azithromycin [Zithromax 250mg, 500mg, 1000mg] Z-pack

Drug Nomenclature

International Nonproprietary Names (INNs) in main languages (French, Latin, Russian, and Spanish):

Pharmacopoeias. In China, and Japan. Europe includes the anhydrous form. US includes the monohydrate and the dihydrate. European Pharmacopoeia, 6th ed., 2008 and Supplements 6.1 and 6.2 (Azithromycin). A white or almost white powder. Practically insoluble in water; freely soluble in dehydrated alcohol and in dichloromethane. A 0.2% solution in a mixture of methyl alcohol and water (1:1) has apH of 9.0 to 11.0. Store in airtight containers. The United States Pharmacopeia 31, 2008 (Azithromycin). It is anhydrous or contains one or two molecules of water of hydration. pH of a 0.2% solution in a mixture of methyl alcohol and water (1:1) is between 9.0 and 11.0. Store in airtight containers.

Adverse Effects and Precautions

As for Erythromycin

Gastrointestinal disturbances are the most frequent adverse effect of azithromycin but are usually mild and less frequent than with erythromycin. Headache, somnolence, and taste disturbances may occur. Severe hypersensitivity reactions occur rarely but may be prolonged. Thrombocytopenia and mild transient neutropenia have been rarely reported in patients receiving azithromycin. Pain and inflammation may occur at the site of intravenous infusions particularly at high concentrations. Licensed product information states that azithromycin should be used with caution in patients with hepatic or renal impairment. It should not be given to those with severe hepatic impairment as safety has not been established. Although plasma concentrations may be increased in renal impairment dosage adjustment is not usually required.

Incidence of adverse effects

In patients receiving azithromycin daily long-term for mycobacterial infections, gastrointestinal disorders occurred in 32 of 39 patients (82%), hearing impairment in 10 patients (26%), tinnitus in 18 patients (46%), and poor balance or dizziness in 11 patients (28%). In general, adverse effects were associated with higher serum-azithromycin concentrations.

Effects on the ears

Reversible sensorineural hearing loss was reported in 3 patients given oral azithromycin 500 mg daily with clofazimine and ethambutol for the treatment of disseminated Mycobacterium avium complex infection. Irreversible hearing loss has also been reported after low-dose exposure to oral azithromycin. A patient who had had 8 days of treatment with intravenous azithromycin 500 mg daily for pneumonia reported complete deafness, which had resolved 20 days after stopping the drug. See also Incidence of Adverse Effects, above.

Effects on fluid and electrolyte homoeostasis

The syndrome of inappropriate antidiuretic hormone secretion was associated with azithromycin treatment in a patient.

Effects on the kidneys

Acute interstitial nephritis leading to irreversible renal failure has been reported in a patient who received azithromycin for 9 days. A later report described a patient who developed recurrent acute interstitial nephritis after courses of azithromycin. Repeated exposure resulted in persistent renal damage; leucocytosis and eosinophilia were still present 1 year later.

Eosinophilia

A syndrome characterised by eosinophilia, arthralgia, fever, and rash was associated with azithromycin or roxifhromycin treatment in a patient on separate occasions. The original authors believed the condition represented the Churg-Strauss syndrome, although this was disputed in correspondence and attributed to the eosinophilia-myalgia syndrome.

Overdosage

Bradycardia with complete heart block was reported in a 9-month-old infant who had been inadvertently given about 50 mg/kg of azithromycin intravenously.

Interactions

For a discussion of drug interactions of macrolide antibacterials, see Erythromycin. Giving azithromycin with antacids containing aluminium or magnesium salts can reduce the rate, but not the extent, of its absorption; azithromycin should be given at least 1 hour before or 2 hours after the antacid.

Nelfinavir

Azithromycin serum concentrations are markedly increased when it is given with nelfinavir, but the clinical significance of this is uncertain. US licensed product information for azithromycin states that dosage adjustment is not required although the patient should be closely monitored for adverse effects.

Antimicrobial Action

As for Erythromycin. Azithromycin is less active than erythromycin against streptococci and staphylococci, but has greater activity than erythromycin in vitro against some Gram-negative organisms such as Haemophilus influenzae and Moraxella catarrhalis (Branhamella catarrhalis), as well as having activity against some of the Enterobacteriaceae such as Escherichia coli and Salmonella and Shigella spp. Azithromycin is also more active than erythromycin against Chlamydia trachomatis and Ureaplasma urealyticum, and some opportunistic mycobacteria, including Mycobacterium avium complex. It has activity against the protozoa Toxoplasma gondii and Plasmodium falciparum.

Resistance

The pattern of resistance to azithromycin is similar to that seen with clarifhromycin.

Pharmacokinetics

Azithromycin given orally is rapidly absorbed and about 40% bioavailable. Absorption from capsules, but not tablets or suspension, is reduced by food. Peak plasma concentrations occur 2 to 3 hours after an oral dose and 1 to 2 hours after intravenous dosage. However, azithromycin is extensively distributed into the tissues, and tissue concentrations subsequently remain much higher than those in the blood; in contrast to most other antibacterials, plasma concentrations are therefore of little value as a guide to efficacy. High concentrations are taken up into white blood cells. There is little diffusion into the CSF when the meninges are not inflamed. Data from animal studies indicate that azithromycin crosses the placenta. Small amounts of azithromycin are demethylated in the liver, and it is excreted in bile mainly as unchanged drug and a number of inactive metabolites have also been detected. About 6% of an oral dose (representing about 20% of the amount in the systemic circulation) is excreted in the urine. The terminal elimination half-life is about 68 hours.

Uses and Administration

Azithromycin is a nitrogen-containing macrolide (azalide) with actions and uses similar to those of erythromycin. It is given in the treatment of respiratory-tract infections (including otitis media), in skin and soft-tissue infections, and in uncomplicated genital infections. Azithromycin may also be used for the prophylaxis, and as a component of regimens in the treatment, of Mycobacterium avium complex (MAC) infections. It is used in some countries for the prophylaxis of endocarditis in atrisk patients unable to take penicillin. It is also used in the management of trachoma and typhoid. For details of all these infections and their treatment, see under Choice of Antibacterial. Azithromycin has been tried in protozoal infections such as babesiosis (below), crytosporidiosis, and toxoplasmosis. It is given orally or by intravenous infusion usually as the dihydrate; doses are expressed in terms of the anhydrous substance. Azithromycin dihydrate 524 mg is equivalent to about 500 mg of anhydrous azithromycin. The capsule formulation should be given at least 1 hour before, or 2 hours after, meals. The usual oral adult dose of azithromycin is 500 mg as a single dose daily for 3 days. Alternatively, an initial dose of 500 mg may be followed by 250 mg daily for a further 4 days. For uncomplicated genital infections caused by Chlamydia trachomatis and for chancroid, 1 g of azithromycin is given as a single dose. A single dose of 2 g has been given for uncomplicated gonorrhoea. For the treatment of granuloma inguinale, an initial dose of 1 g followed by 500 mg daily may be given, or 1 g may be given once a week for at least 3 weeks, until all lesions have completely healed. In the USA, a modified-release preparation given as an oral suspension is available. The product delivers a single dose of 2 g and should also be taken on an empty stomach. It is licensed for the treatment of acute bacterial sinusitis or community-acquired pneumonia in adults. For prophylaxis of disseminated MAC infections, azithromycin 1.2 g may be given once weekly. For treatment or secondary prophylaxis, 500 mg once daily should be given with other antimycobacterials. For mild or moderate typhoid caused by mumdrug-resistant strains, 500 mg once daily may be given for 7 days. For details of doses in infants and children, see below. Azithromycin dihydrate may also be given initially by intravenous infusion to adults in doses equivalent to 500 mg of azithromycin as a single daily dose in the treatment of community-acquired pneumonia and pelvic inflammatory disease; treatment should be changed to the oral route after at least 2 days in pneumonia and after 1 or 2 days in pelvic inflammatory disease. It may be given either in a solution containing 1 mg/mL over 3 hours or in a solution containing 2 mg/mL over 1 hour. In the USA, azithromycin is available as 1% eye drops for the topical treatment of conjunctivitis caused by susceptible strains of bacteria.

Administration in children

Azithromycin is licensed for use in infants and children and the usual oral dose in those over 6 months of age is 10 mg/kg once daily for 3 days, or an initial dose of 10 mg/kg may be followed by 5 mg/kg daily for a further 4 days; those who weigh over 45 kg may be given the usual adult dose (see above). A single dose of 30 mg/kg may also be given for acute otitis media. For pharyngitis or tonsillitis in children aged over 2 years, 12 mg/kg once daily for 5 days may be given. US official guidelines suggest that for prophylaxis of disseminated Mycobacterium avium complex infections, azithromycin 20 mg/kg (to a maximum of 1.2 g) once weekly or 5 mg/kg (to a maximum of 250 mg) once daily may be given. For treatment, 10 to 12 mg/kg (to a maximum of 500 mg) once daily should be given with other antimycobacterials. In the UK, the BNFC suggests that azithromycin may be used in penicillin allergic children for the prevention of secondary cases of group A streptococcal infection; those 6 months and older may be given an oral dose of 12 mg/kg (to a maximum of 500 mg) once daily for 5 days. The BNFC also suggests giving azithromycin 10 mg/kg once daily for 7 days in the treatment of mild to moderate typhoid caused by multidrug-resistant strains in those aged 6 months and over.

Babesiosis

In a prospective, randomised study involving 58 patients with babesiosis, azithromycin with atovaquone was found to be as effective as, and associated with fewer adverse effects than, standard therapy with quinine and clindamy-cin. Azithromycin 600 mg once daily, or 500 to 1000 mg on day 1 followed by 250 mg once daily thereafter, with atovaquone 750 mg twice daily, both orally for 7 to 10 days, has been recommended by some experts in the USA for the treatment of Babesia microti infections. Immunocompromised patients may be given higher doses of azithromycin (600 to 1000 mg daily). Children may be given azithromycin 12 mg/kg once daily, or 10 mg/kg on day 1 followed by 5 mg/kg once daily thereafter, with atovaquone 20 mg/kg twice daily, both orally for 7 to 10 days. Azithromycin with quinine was reported to be effective in 2 patients who had not responded to quinine plus clindamycin.

Cholera

Azithromycin has been tried in the treatment of cholera. A single dose of 10 or 20 mg/kg was found to be effective in children and 1 g in adults.

Hyperplasia

For reference to the use of azithromycin to control ciclosporin-induced gingival hyperplasia.

Ischaemic heart disease

Macrolide antibacterials, including azithromycin, clarithromycin, and roxithromycin, have been investigated in the prevention of ischaemic heart disease, based on a suggested link between atherosclerosis and infection with Chlamydophila pneumoniae (Chlamydia pneumoniae). Although preliminary results from some pilot studies were promising, longer-term studies in large numbers of patients were disappointing and none of the three macrolides decreased ischaemic events or provided clinical benefit; indeed, in one study an unexpected increase in cardiovascular mortality was seen in those taking clarithromycin.

Malaria

Azithromycin has been studied in the management of malaria. Studies have shown that an initial loading dose of 750 mg of azithromycin on the first day followed by 250 mg daily thereafter for 20 weeks was effective in the prophylaxis of Plasmodium vivax malaria; the drug was well tolerated and the most frequently reported adverse effects were heartburn, paraes-thesia, and itching. In the treatment of Plasmodium vivax malaria, a study found that azithromycin 1 g daily for 3 days resulted in an 88% clinical response rate by day 7, but with a slower onset of action, when compared with chloroquine 600 mg daily for 2 days then 300 mg on day 3 which resulted in a rate of 99%. Azithromycin in a dose of 0.5 g once daily up to 1.5 g daily in divided doses together with other antimalarials, such as artesuna-te 200 mg daily or quinine 10 mg/kg 3 times daily, given for 3 days was found to be effective in the treatment of uncomplicated multi drug-resistant Plasmodium falciparum malaria. However, further studies are warranted, especially in children and pregnant women.

Respiratory disorders

For reference to the use of azithromycin in the management of respiratory disorders, see under Erythromycin.

Preparations

The United States Pharmacopeia 31, 2008: Azithromycin Capsules.

Single-ingredient Preparations

Argentina: Arzomicin; Azitral; Azitrona; Clearsing; Cronopen; Doyle; Fabramicina; Finatres; Macromax; Misultina; Naxocina; Neblic; Nifostin; Novozitron; Orobiotic; Sitrox; Sumir; Tanezox; Triamid; Tritab; Vectocilina; Zitromax; Australia: Zithromax; Austria: Zithromax; Belgium: Zitromax; Brazil: Atromicin; Azatill; Azi; Azidromic; Azimax; Azimix; Azitrax; Azitrin; Azitrocin; Azitromicil; Azitromin; Azitron; Azitronax; Azitroxil; Biozitrom; Clindal; Clindaz; Ems-Max; Mac Azi; Mazitrom; Novatrex; Selimax; Siftromin; Triazi; Tromix; Trozyman; Zimicina; Zitril; Zitromax; Zitromil; Zitroneo; Canada: Z-Pak; Zithromax; Chile: Abacten; Asipral; Atizor; Azitrom; Ricilina; Trex; Zithromax; Czech Republic: Azitrox; Sumamed; Denmark: Zitromax; Finland: Zithromax; France: Azadose; Zithromax; Germany: Ultreon; Zithromax; Greece: Zithromax; Hong Kong: Zithromax; Hungary: Sumamed; India: Azee; Azibact; Azifast; Azithral; Aziwok; Zithrocin; Zycin; Ireland: Zithromax; Israel: Azenil; Zeto; Zithromax; Italy: Azitrocin; Ribotrex; Trozocina; Zitromax; Malaysia: Zithromax; Mexico: Aziphar; Azitrocin; Azo-Max; Koptin; Macrozit; Medatz; Truxa; Zertalin; Zitroken; Netherlands: Azitromerck; Merckazitro; Zithromax; Norway: Azitromax; New Zealand: Zithromax; Portugal: 3Z; Arzomicina; Azitrix; Farmiz; Gigatrom; Neofarmiz; Unizitro; Zithromax; Zitrozina; Russia: Aziwok (Азивок); Hemomycin (Хемомицин); Sumamed (Сумамед); ZI-Factor (ЗИ-фактор); South Africa: Zithromax; Singapore: Zithromax; Spain: Altezym; Goxil; Toraseptol; Vinzam; Zentavion; Zitromax; Sweden: Azitromax; Switzerland: Zithromax; Thailand: Zithromax; United Arab Emirates: Azomycin; United Kingdom: Zithromax; United States: Zithromax; Zmax; Venezuela: Aruzilina; Arzomidol; Atromizin; Azigram; Azimakrol; Azitromin; Saver; Zitromax; Zival;

Multi-ingredient Preparations

India: Orflaz Kit; Safkit

Is Zithromax a derivative or 3rd generation E-mycin and what are side effects?

Yes. Azithromycin (Zithromax) is chemically a “macrolide antibiotic” like erythromycin (E-Mycin), but has extended antibacterial coverage. Side effects are similar to E-Mycin, but usually milder.

Synonyms of Azithromycin:

Aritromicina [Spanish], Azithramycine, Azithromycin Dihydrate, Azithromycine [French], Azithromycinum [Latin]

How can i get Azithromycin online over the counter?

You can buy Azithromycin OTC in online drugstore with low cost.

Therapeutic classes of Azithromycin:

Anti-Bacterial Agents, Macrolides, Other Macrolides

Delivery

Australia, Canada, Mexico, New Zealand, USA, Europe [Belgium, France, Norway, Holland, Ireland, Spain, Switzerland, Great Britain (UK), Italy] and etc.