indication

For the treatment of acute bacterial exacerbations of chronic bronchitis

pharmacology

Methacycline is a tetracycline antibiotic. Similar to other tetracyclines, it has a wide spectrum of antimicrobial action. It is active against most Gram-positive bacteria (pneumococci, streptococci, staphylococci) and Gram-negative bacteria (E. coli, salmonella, shigella, etc.), and towards agents causing onithosis, psittacosis, trachoma, and some Protozoa. Like other tetracyclines, the general usefulness of methacycline has been reduced with the onset of bacterial resistance.

mechanism of action

Methacycline, a tetracycline antibiotic, is a protein synthesis inhibitors, inhibiting the binding of aminoacyl-tRNA to the mRNA-ribosome complex. Methacycline inhibits cell growth by inhibiting translation. It binds to the 16S part of the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. The binding is reversible in nature. Tetracyclines also have been found to inhibit matrix metalloproteinases. This mechanism does not add to their antibiotic effects, but has led to extensive research on chemically modified tetracyclines or CMTs (like incyclinide) for the treatmet of rosacea, acne, and various types of neoplasms.

absorption

58% absorbed

half life

14 hours

drug interactions

Acitretin: Increased risk of intracranial hypertension

Amoxicillin: Possible antagonism of action

Ampicillin: Possible antagonism of action

Calcium: Formation of non-absorbable complexes

Carbenicillin: Possible antagonism of action

Clavulanate: Possible antagonism of action

Cloxacillin: Possible antagonism of action

Dicloxacillin: Possible antagonism of action

Ethinyl Estradiol: This anti-infectious agent could decrease the effect of the oral contraceptive

Etretinate: Increased risk of intracranial hypertension

Flucloxacillin: Possible antagonism of action

Iron Dextran: Formation of non-absorbable complexes

Isotretinoin: Increased risk of intracranial hypertension

Magnesium: Formation of non-absorbable complexes

Penicillin G: Possible antagonism of action

Penicillin V: Possible antagonism of action

Piperacillin: Possible antagonism of action

Pivampicillin: Possible antagonism of action

Pivmecillinam: Possible antagonism of action