Reals Pharmaceuticals Limited
Plot 1 Junaid Dosunmu Street,Central Business District, Alausa, P.0. Box 3560 Ikeja, Lagos, Nigeria.
Tel: + 234-1-774-1205
Fax: +234-1-263-0919

Brand Name



Fredun Pharmaceuticals Ltd, 26, Manoj Industrial Premises, G.D. Ambekar Marg. Wadala, Mumbai-400 031, India.

Therapeutic Class

Antibacterial, Macrolides

Dosage Form, Composition & NAFDAC Registration Number (NRN)

Tablet (NRN: 04-7696): Clarithromycin 500 mg.

Pack Size:


Clarithromycin is a semi-synthetic macrolide antibiotic. Like other macrolides, clarithromycin binds to the 50 S subunit of the 70 S ribosome, thereby blocking RNA-mediated bacterial protein synthesis. Clarithromycin can be bacteriostatic or bactericidal in action, depending on the concentration as well as the particular organism and its inoculum. The minimum inhibitory concentrations (MICs) of clarithromycin are generally two-fold lower than the MICs of erythromycin.

Pharmacokinetics: Clarithromycin is rapidly and well absorbed from the gastro-intestinal tract after oral administration of clarithromycin. The microbiological active metabolite 14-hydroxyclarithromycin is formed by first pass metabolism. Clarithromycin may be given without regard to meals as food does not affect the extent of bioavailability of clarithromycin. Food does slightly delay the onset of absorption of clarithromycin and formation of the 14-hydroxymetabolite.

The pharmacokinetics of clarithromycin are non linear, however, steady state is attained within 2 days of dosing. At 250 mg b.i.d. 15-20% of unchanged drug is excreted in the urine. With 500 mg b.i.d daily dosing urinary excretion is greater (approximately 36%). The 14-hydroxyclarithromycin is the major urinary metabolite and accounts for 10-15% of the dose. Most of the remainder of the dose is eliminated in the faeces, primary via the bile. 5-10% of the parent drug is recovered form the faeces. When clarithromycin 500 mg is given three times daily, the clarithromycin plasma concentrations are increased with respect to the 500 mg twice daily dosage.

Clarithromycin provides tissue concentrations that are several times higher than the circulating drug levels. Increased levels have been found in both tonsillar and lung tissue. Clarithromycin is 80% bound to plasma proteins at therapeutic levels.

Clarithromycin also penetrates the gastric mucus. Levels of clarithromycin in gastric mucus and gastric tissue are higher when clarithromycin is co-administered with omeprazole than when clarithromycin is administered alone. Clarithromycin penetrates into the middle ear fluid at concentrations greater than in the serum.


Highly potent against a wide variety of aerobic and anaerobic gram-positive and gram-negative organisms.

Respiratory tract infections; Ear, nose and throat infections; Community acquired pneumonia; Disseminated mycobacterial infections due to Mycobacterium avium or Mycobacterium intracellulae; Prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.

Treatment of H. pylori infections in combination with other drugs such as lansoprazole, omeprazole, rantidine, bismuth, amoxycillin etc.


Clarithromycin is contra-indicated in patients with a known hypersensitivity to clarithromycin, erythromycin, or any of the macrolide antibiotics. It is also contraindicated in pregnancy. Concomitant administration of clarithromycin with cisapride, pimozide, or terfenadine is contraindicated.

Clarithromycin and ergot derivatives should not be co-administred.clarithromycin may potentiate the effects of carbamazephine due to a reduction in the rate of excretion.



Adverse Effects

The majority of side effects observed in clinical trials were of a mild and transient nature. Fewer than 3% of adult patients without mycobacterial infections and few than 2% of pediatric patients without mycobacterial infections discontinued therapy because of drug-related side effects.

The most frequently reported events in adults were diarrhoea, nausea, abnormal taste, dyspepsia, abdominal pain/discomfort and headache.

In paediatric patients, the most frequently reported events were diarrhoea, vomiting, abdominal pain, rash and headache. Most of these events were described as mild or moderate in severity.

H. pylori organisms may develop resistance to Clarithromycin in a small number of patients.

Dosage & Administration

The usual dosage of clarithromycin is 250 mg twice daily. Although this may be increased to 500 mg twice daily for up to 14 days in severe infections.

The recommended dose of clarithromycin for the prevention of disseminated Mycobacterium avium disease is 500 mg bid.

Clarithromycin is recommended as the primary agent for the treatment of disemminated infection due to Mycobacterium avium complex. In the treatment of Mycobacterium avium complex, clarithromycin should be used in combination with other antimycobacterial drugs. The recommended dose for mycobacterial infections in adults is 500 mg bid.

In children, the dose is 7.5 mg to 15 mg/kg 12 hourly.

Clarithromycin may be administered without dosage adjustment in the presence of hepatic impairment if there is normal renal function. However, in the presence of severe renal impairment (creatinine clearance

Effects on ability to drive the use of machines: The medicine is unlikely to produce an effect.

Storage/Handling Recommendations

Clarithromycin tablets have a shelf life of 24 months when stored in Alu\PVC\PVDC blisters in a cool dry place.

Do not store above 30oC.

Protect from sun light.

Review Date

2015-11-19 07:12:57