CLARITHROMYCIN

MACROLIDES

Cross and Allergic Reactions

Usage

Amoxicillin should not be taken if one has- Mononucleosis, Colitis, Diabetes, Renal Dysfunction, Pku (Phenylketonuria), Hemodialysis--Dose needs to be decreased when in pregnancy

Type

This is the class of antibiotics which is often prescribed for patients who are allergic to beta lactams. They have a good coverage of aerobics both gram positive and gram negative as mentioned below. The first antibiotic in this group was Erythromycin. Roxithromycin, azithromycin and clarithromycin are other antibiotics in this group.

Oral and intravenous forms are available.

Clarithromycin acts as bacteriostatic* at low and bactericidal* at higher concentrations. Clarithromycin exerts its antibacterial action by binding to the 50s ribosomal subunit of susceptible bacteria and suppresses protein synthesis.

It is a first line drug in combination regimens for MAC infection in AIDS patients and a second line drug for other atypical mycobacterial diseases as well as leprosy.

History

Clarithromycin was invented by researchers at the Japanese drug company Taisho Pharmaceutical in 1980.

Usage

They are most commonly prescribed macrolides, used for upper and lower respirator tract infections and prevention of bacterial endocarditic. They can also be used for sinusitis, otitis media, atypical pneumonia.

Should not be taken if

Should not taken in pregnancy and during lactation

Should not be taken if allergic to other macrolides or the ingredients in the tablets which include microcrystalline cellulose, croscarmellose sodium, magnesium stearate and povidone

Should not be used in people with a history of cholestatic jaundice and/or liver dysfunction associated with prior clarithromycin use

In people with hypokalaemia (low blood potassium)

Use of clarithromycin with the following medications: cisapride, pimozide, astemizole, terfenadine, ergotamine, ticagrelor, ranolazine or dihydroergotamine is not recommended

It should not be used with colchicine in people with kidney or liver impairment

Concomitant use with cholesterol medications such as lovastatin or simvastatin

Hypersensitivity to clarithromycin or any component of the product, erythromycin, or any macrolide antibiotics

Should not be used in patients with QT prolongation or ventricular cardiac arrhythmias, including torsade de pointes

Cross and Allergic Reactions

Clarithromycin cross reacts with other macrolides Clindamycin and Chloramphenicol

It causes allergic reactions such as rash and fever

Reacts with

Theophylline

Carbamazepine
Valproate
Ergotamine
Warfarin
Terfenadine
Astemizole
Cisapride

Drugs strictly contraindicated for use with clarithromycin are-

Cisapride, pimozide, astemizole and terfenadine
Ergotamine/dihydroergotamine
HMG-CoA reductase inhibitors (statins)

Side Effects

The most common side effects are gastrointestinal: diarrhea (3%), nausea (3%), abdominal pain (3%), and vomiting (6%).

Few cases of pseudomembranous enterocolitis have been reported

It also can cause headaches, insomnia, and abnormal liver function tests.

Allergic reactions include rashes and anaphylaxis.

Less common side effects (<1%) include extreme irritability, hallucinations (auditory and visual), dizziness/motion sickness, and alteration in senses of smell and taste, including a metallic taste.

Dry mouth, panic attacks, and nightmares have also been reported, albeit less frequently

Few cases of rhabdomyolysis and hepatic dysfunction reported.

It can cause QT prolongation on ECG, ventricular arrhythmias and rarely death

Rarely, it can cause ototoxicity, delirium and mania

Oral yeast infections have been reported.

Shelf Life

Shelf Life:- 3 years from manufacturing date, more than that can cause less effectiveness