Roxithromycin
Encyclopedia
Roxithromycin is a semi-synthetic macrolide
antibiotic
. It is used to treat respiratory tract, urinary and soft tissue infections. Roxithromycin is derived from erythromycin
, containing the same 14-membered lactone ring. However, an N-oxime side chain
is attached to the lactone ring. It is also currently undergoing clinical trials for the treatment of male-pattern hair loss.
Roxithromycin is available under several brandnames, for example, Xthrocin, Roxl-150, Roxo, Surlid, Rulide, Biaxsig, Roxar, Roximycin, Roxomycin, Rulid, Tirabicin and Coroxin. Roxithromycin is not available in the United States. Roxithromycin has also been tested to possess antimalarial activity.
brought out roxithromycin in 1987.
, and thus inhibits the translocation of peptide
s. Roxithromycin has similar antimicrobial spectrum as erythromycin, but is more effective against certain gram-negative bacteria, particularly Legionella pneumophila
.
s. Due to the high concentration in phagocytes, roxithromycin is actively transported to the site of infection. During active phagocytosis, large concentrations of roxithromycin are released.
as it has a lower affinity for cytochrome P450.
Roxithromycin does not interact with hormonal contraceptives
, prednisolone
, carbamazepine
, ranitidine
or antacids.
When roxithromycin is administered with theophylline
, some studies have shown an increase in the plasma
concentration of theophylline
. A change in dosage is usually not required but patients with high levels of theophylline
at the start of the treatment
should have their plasma levels monitored.
Roxithromycin appears to interact with warfarin
. This is shown by an increase in prothrombin time (international normalised ratio [INR]) in patients taking roxithromycin and warfarin
concurrently. As a consequence, severe bleeding episodes have occurred.
Mode of Administration- Oral.
Macrolide
The macrolides are a group of drugs whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered...
antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
. It is used to treat respiratory tract, urinary and soft tissue infections. Roxithromycin is derived from erythromycin
Erythromycin
Erythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...
, containing the same 14-membered lactone ring. However, an N-oxime side chain
Side chain
In organic chemistry and biochemistry, a side chain is a chemical group that is attached to a core part of the molecule called "main chain" or backbone. The placeholder R is often used as a generic placeholder for alkyl group side chains in chemical structure diagrams. To indicate other non-carbon...
is attached to the lactone ring. It is also currently undergoing clinical trials for the treatment of male-pattern hair loss.
Roxithromycin is available under several brandnames, for example, Xthrocin, Roxl-150, Roxo, Surlid, Rulide, Biaxsig, Roxar, Roximycin, Roxomycin, Rulid, Tirabicin and Coroxin. Roxithromycin is not available in the United States. Roxithromycin has also been tested to possess antimalarial activity.
History
German pharmaceutical company Hoechst UclafHoechst AG
Hoechst AG was a German chemicals then life-sciences company that became Aventis Deutschland after its merger with France's Rhône-Poulenc S.A. in 1999...
brought out roxithromycin in 1987.
Mechanism of action
Roxithromycin prevents bacteria from growing, by interfering with their protein synthesis. Roxithromycin binds to the subunit 50S of the bacterial ribosomeRibosome
A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....
, and thus inhibits the translocation of peptide
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
s. Roxithromycin has similar antimicrobial spectrum as erythromycin, but is more effective against certain gram-negative bacteria, particularly Legionella pneumophila
Legionella pneumophila
Legionella pneumophila is a thin, ærobic, pleomorphic, flagellated, non-spore forming, Gram-negative bacterium of the genus Legionella. L. pneumophila is the primary human pathogenic bacterium in this group and is the causative agent of legionellosis or Legionnaires' disease.-Characterization:L...
.
Pharmacokinetics
When taken before a meal, roxithromycin is very rapidly absorbed, and diffused into most tissues and phagocytePhagocyte
Phagocytes are the white blood cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells. Their name comes from the Greek phagein, "to eat" or "devour", and "-cyte", the suffix in biology denoting "cell", from the Greek kutos, "hollow vessel". They are...
s. Due to the high concentration in phagocytes, roxithromycin is actively transported to the site of infection. During active phagocytosis, large concentrations of roxithromycin are released.
Metabolism
Only a small portion of roxithromycin is metabolised. Most of roxithromycin is secreted unchanged into the bile and some in expired air. Under 10% is excreted into the urine. Roxithromycin's half-life is 12 hours.Side effects
Most common side effects are gastrointestinal; diarrhoea, nausea, abdominal pain and vomiting. Less common side effects include central or peripheral nervous system events such as headaches, dizziness, vertigo, and also the rarely seen rashes, abnormal liver function values and alteration in senses of smell and taste.Drug interactions
Roxithromycin has fewer interactions than erythromycinErythromycin
Erythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...
as it has a lower affinity for cytochrome P450.
Roxithromycin does not interact with hormonal contraceptives
Hormonal contraception
Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive...
, prednisolone
Prednisolone
Prednisolone is the active metabolite of prednisone, which is also used as a drug.-Uses:Prednisolone is a corticosteroid drug with predominant glucocorticoid and low mineralocorticoid activity, making it useful for the treatment of a wide range of inflammatory and auto-immune conditions such as...
, carbamazepine
Carbamazepine
Carbamazepine is an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder, as well as trigeminal neuralgia...
, ranitidine
Ranitidine
Ranitidine is a histamine H2-receptor antagonist that inhibits stomach acid production. It is commonly used in treatment of peptic ulcer disease and gastroesophageal reflux disease . Ranitidine is also used alongside fexofenadine and other antihistamines for the treatment of skin conditions...
or antacids.
When roxithromycin is administered with theophylline
Theophylline
Theophylline, also known as dimethylxanthine, is a methylxanthine drug used in therapy for respiratory diseases such as COPD and asthma under a variety of brand names. Because of its numerous side-effects, the drug is now rarely administered for clinical use. As a member of the xanthine family, it...
, some studies have shown an increase in the plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
concentration of theophylline
Theophylline
Theophylline, also known as dimethylxanthine, is a methylxanthine drug used in therapy for respiratory diseases such as COPD and asthma under a variety of brand names. Because of its numerous side-effects, the drug is now rarely administered for clinical use. As a member of the xanthine family, it...
. A change in dosage is usually not required but patients with high levels of theophylline
Theophylline
Theophylline, also known as dimethylxanthine, is a methylxanthine drug used in therapy for respiratory diseases such as COPD and asthma under a variety of brand names. Because of its numerous side-effects, the drug is now rarely administered for clinical use. As a member of the xanthine family, it...
at the start of the treatment
Pharmacotherapy
Pharmacotherapy is the treatment of disease through the administration of drugs. As such, it is considered part of the larger category of therapy....
should have their plasma levels monitored.
Roxithromycin appears to interact with warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
. This is shown by an increase in prothrombin time (international normalised ratio [INR]) in patients taking roxithromycin and warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
concurrently. As a consequence, severe bleeding episodes have occurred.
Drug Dosage
Adults: 150mg twice in a day, 1-2 hours before meals. For children, it is 2.5 - 5.0mg/kg of body weight, given in two divided doses per day.Mode of Administration- Oral.