Drug information of Roxithromycin

Mechanism of effect

Roxithromycin prevents bacterial growth by interfering with their protein synthesis. It binds to the 50S subunit of bacterial ribosomes and inhibits the translocation of peptides

Pharmacodynamic

Roxithromycin has the following antibacterial spectrum in vitro: Streptococcus agalactiae, Streptococcus pneumoniae (Pneumococcus), Neisseria meningitides (Meningococcus), Listeria monocytogenes, Mycoplasma pneumoniae, Chlamydia trachomatis, Ureaplasma urealyticum, Legionella pneumophila, Helicobacter (Campylobacter), Gardnerella vaginalis, Bordetella pertussis, Moraxella catarrhalis (Branhamella Catarrhalis), and Haemophilus ducreyi.

Roxithromycin is highly concentrated in polymorphonuclear leukocytes and macrophages, achieving intracellular concentrations greater than those outside the cell. Roxithromycin enhances the adhesive and chemotactic functions of these cells which in the presence of infection produce phagocytosis and bacterial lysis. Roxithromycin also possesses intracellular bactericidal activity.

Pharmacokinetics

Absorption

Very rapidly absorbed and diffused into most tissues and phagocytes

Protein binding

96%, mainly to alpha1-acid glycoproteins

Metabolism

Hepatic. Roxithromycin is only partially metabolised, more than half the parent compound being excreted unchanged. Three metabolites have been identified in urine and faeces: the major metabolite is descladinose roxithromycin, with N-mono and N-di-demethyl roxithromycin as minor metabolites. The respective percentage of roxithromycin and these three metabolites is similar in urine and faeces.

Drug indications

Used to treat respiratory tract, urinary and soft tissue infections

• acute pharyngitis (sore throat and discomfort when swallowing)
• tonsillitis
• sinusitis
• acute bronchitis (infection of the bronchi causing coughing)
• exacerbation of chronic bronchitis
• pneumonia (lung infection characterised by fever, malaise, headache)
• skin and soft tissue infections
• non gonococcal urethritis
• impetigo (bacterial infection causing sores on the skin).

Dosage

You may take this according to one of the following dosage regimens:

• one 300mg tablet once a day, or
• one 150mg tablet twice a day, or
• two 150 mg tablets once a day.

• The recommended dose for children weighing 40kg and more is 150mg twice a day.

Roxithromycin Sandoz should not be used for children less than 40kg in weight

Drug contraindications

known hypersensitivity to macrolides, including erythromycin • severely impaired hepatic function) • concomitant therapy with vasoconstrictive ergot alkaloids

Side effects

• oral thrush with a white, furry, sore tongue and mouth
• vaginal thrush with a sore and itchy vagina and/or discharge
• nausea, vomiting, stomach pain, diarrhoea, , loss of appetite
• red and/or itchy skin, skin rash
• headache, tiredness, dizziness, ringing in the ears
• hallucinations
• altered taste and/or smell.
• Blurred vision and /or visual impairment
• severe abdominal or stomach cramps
• watery and severe diarrhoea, which may even be bloody
• fever, in combination with one or both of the above

Interactions

Protamine sulfat , Methylergonovin , Dalteparin , Tinzaparin , Pimozide , Theophyline , Dihydroergotamine , Disopyramide , Digoxin , Cisapride , Cyclosporine , Midazolam , Warfarin , astemizole , Terfenadine , Calcium pantothenate , Typhoid vaccine (live), oral , Vernakalant

• theophylline, some medicines for migraine headache such as ergotamine or dihydroergotamine, disopyramide, terfenadine and astemizole, warfarin, digoxin, midazolam, cyclosporine, cisapride, pimozide

Alerts

Prolonged or repeated use of antibiotics including roxithromycin may result in superinfection by resistant organisms. In the event of superinfection, roxithromycin should be discontinued and appropriate therapy instituted.

 

Prolongation of the QT Interval

 Ventricular arrhythmias associated with prolonged QT interval, including ventricular tachycardia and torsades de pointes have been reported with macrolide antibiotics including roxithromycin. Prescribers should consider the risk of QT prolongation (which can be fatal) when weighing the risks and benefits of roxithromycin for at-risk groups including: • Patients predisposed to QT interval prolongation such as those with a history of torsades de pointes or congenital long QT syndrome. • Patients taking other medication known to prolong the QT interval such as antiarrhythmics of classes IA and III; antipsychotic agents; antidepressants; and fluoroquinolones. • Patients with electrolyte disturbance, particularly in cases of hypokalaemia and hypomagnesaemia. • Patients with clinically relevant bradycardia, cardiac arrhythmia or cardiac insufficiency

 

Impaired hepatic function

 Caution should be exercised if roxithromycin is administered to patients with impaired hepatic function, as its serum half life is increased in patients with hepatic failure. If administered to patients with severe hepatic insufficiency (e.g. hepatic cirrhosis with jaundice and/or ascites), the dose should be reduced by half to 150 mg once daily

 

Points of recommendation

Tell your doctor if you have or have had any of the following medical conditions:

• impaired kidney function
• problems with your liver (hepatic cirrhosis with jaundice and/or ascites).

Tell your doctor if you are pregnant or plan to become pregnant. This medicine is not recommended for use during pregnancy.

Tell your doctor if you are breastfeeding or planning to breastfeed.

Tell your doctor or pharmacist if you plan to have surgery.

Pregnancy level

Pregnancy: B1(Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have not shown evidence of an increased occurrence of fetal damage)