Pfizer-e - General Information
Pfizer-e is a bacteriostatic antibiotic macrolide produced by Streptomyces erythreus. Pfizer-e A is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50S ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins. [PubChem]
Pharmacology of Pfizer-e
Pfizer-e is produced by a strain of Streptomyces erythraeus and belongs to the macrolide group of antibiotics. After absorption, erythromycin diffuses readily into most body fluids. In the absence of meningeal inflammation, low concentrations are normally achieved in the spinal fluid, but the passage of the drug across the blood-brain barrier increases in meningitis. Pfizer-e is excreted in breast milk. The drug crosses the placental barrier, but fetal plasma levels are low. Pfizer-e is not removed by peritoneal dialysis or hemodialysis.
Pfizer-e for patients
Erythromycin is an antibiotic for the treatment of infection. Topical erythromycin may be used to treat acne. Take at regular intervals and complete the entire course of therapy. Notify your physician if you are pregnant or nursing. Notify your physician if you develop severe abdominal pain, yellowing of the skin or eyes, rash, dark urine, or pale stools. May cause nausea, vomiting, or diarrhea; notify your physician if these occur. Erythromycin should be taken on an empty stomach with a full glass of water; may be taken with food if GI upset occurs.
Erythromycin use in patients who are receiving high doses of theophylline may be associated with an increase in serum theophylline levels and potential theophylline toxicity. In case of theophylline toxicity and/or elevated serum theophylline levels, the dose of theophylline should be reduced while the patient is receiving concomitant erythromycin therapy.
Concomitant administration of erythromycin and digoxin has been reported to result in elevated digoxin serum levels. There have been reports of increased anticoagulant effects when erythromycin and oral anticoagulants were used concomitantly. Increased anticoagulation effects due to interactions of erythromycin with various oral anticoagulents may be more pronounced in the elderly.
Concurrent use of erythromycin and ergotamine or dihydroergotamine has been associated in some patients with acute ergot toxicity characterized by severe peripheral vasospasm and dysesthesia.
Erythromycin has been reported to decrease the clearance of triazolam and midazolam and thus may increase the pharmacologic effect of these benzodiazepines.
The use of erythromycin in patients concurrently taking drugs metabolized by the cytochrome P450 system may be associated with elevations in serum levels of these other drugs. There have been reports of interactions of erythromycin with carbamazepine, cyclosporine, tacrolimus, hexobarbital, phenytoin, alfentanil, cisapride, disopyramide, lovastatin, bromocriptine, valproate, terfenadine, and astemizole. Serum concentrations of drugs metabolized by the cytochrome P450 system should be monitored closely in patients concurrently receiving erythromycin.
Erythromycin has been reported to significantly alter the metabolism of nonsedating antihistamines terfenadine and astemizole when taken concomitantly. Rare cases of serious cardiovascular adverse events, including electrocardiographic QT/QTc interval prolongation, cardiac arrest, torsades de pointes, and other ventricular arrhythmias have been observed. In addition, deaths have been reported rarely with concomitant administration of terfenadine and erythromycin.
There have been postmarketing reports of drug interactions when erythromycin is coadministered with cisapride, resulting in QT prolongation, cardiac arrythmias, ventricular tachycardia, ventricular fibrulation, and torsades de pointes, most like due to inhibition of hepatic metabolism of cisapride by erythromycin. Fatalities have been reported.
Patients receiving concomitant lovastatin and erythromycin should be carefully monitored; cases of rhabdomyolysis have been reported in seriously ill patients.
Erythromycin is contraindicated in patients with known hypersensitivity to this antibiotic. Erythromycin is contraindicated in patients taking terfenadine, astemizole, or cisapride. Topical Ery 2% Pads are contraindicated in those individuals who have shown hypersensitivity to any of its components.
Additional information about Pfizer-e
Pfizer-e Indication: For use in the treatment of infections caused by susceptible strains of microorganisms in the following diseases: respiratory tract infections (upper and lower) of mild to moderate degree, pertussis (whooping cough), as adjunct to antitoxin in infections due to Corynebacterium diphtheriae, in the treatment of infections due to Corynebacterium minutissimum, intestinal amebiasis caused by Entamoeba histolytica, acute pelvic inflammatory disease caused by Neisseria gonorrhoeae, skin and soft tissue infections of mild to moderate severity caused by Streptococcus pyogenes and Staphylococcus aureus, primary syphilis caused by Treponema pallidum, infections caused by Chlamydia trachomatis, nongonococcal urethritis caused by Ureaplasma urealyticum, and Legionnaires' disease caused by Legionella pneumophila.
Mechanism Of Action: Pfizer-e acts by penetrating the bacterial cell membrane and reversibly binding to the 50 S subunit of bacterial ribosomes or near the “P” or donor site so that binding of tRNA (transfer RNA) to the donor site is blocked. Translocation of peptides from the “A” or acceptor site to the “P” or donor site is prevented, and subsequent protein synthesis is inhibited. Pfizer-e is effective only against actively dividing organisms. The exact mechanism by which erythmromycin reduces lesions of acne vulgaris is not fully known: however, the effect appears to be due in part to the antibacterial activity of the drug.
Drug Interactions: Alfentanil The macrolide increases the effect and toxicity of alfentanil
Alprazolam The macrolide increases the effect of the benzodiazepine
Aminophylline The macrolide increases the effect and toxicity of theophylline
Amiodarone Increased risk of cardiotoxicity and arrhythmias
Anisindione The macrolide increases anticoagulant effect
Aprepitant This CYP3A4 inhibitor increases effect and toxicity of aprepitant
Astemizole Increased risk of cardiotoxicity and arrhythmias
Atorvastatin The macrolide possibly increases the statin toxicity
Bretylium Increased risk of cardiotoxicity and arryhthmias
Bromocriptine Pfizer-e increases serum levels of bromocriptine
Buspirone The macrolide increases the effect and toxicity of buspirone
Cabergoline Pfizer-e increases serum levels and toxicity of cabergoline
Carbamazepine The macrolide increases the effect of carbamazepine
Cerivastatin The macrolide possibly increases the statin toxicity
Cilostazol Pfizer-e increases the effect of cilostazol
Cinacalcet This macrolide increases the serum levels and toxicity of cinacalcet
Cisapride Increased risk of cardiotoxicity and arrhythmias
Citalopram Possible serotoninergic syndrome with this combination
Clozapine Pfizer-e increases the effect of clozapine
Colchicine Severe colchicine toxicity can occur
Cyclosporine The macrolide increases the effect of cyclosporine
Diazepam The macrolide increases the effect of the benzodiazepine
Dicumarol The macrolide increases anticoagulant effect
Digoxin The macrolide increases the effect of digoxin in 10% of patients
Dihydroergotamine Possible ergotism and severe ischemia with this combination
Dihydroergotoxine Possible ergotism and severe ischemia with this combination
Dyphylline The macrolide increases the effect and toxicity of theophylline
Disopyramide Increased risk of cardiotoxicity and arrhythmias
Divalproex sodium Pfizer-e increases the effect of valproic acid
Docetaxel The agent increases the serum levels and toxicity of docetaxel
Dofetilide Increased risk of cardiotoxicity and arrhythmias
Eletriptan The macrolide increases the effect and toxicity of eletriptan
Eplerenone This CYP3A4 inhibitor increases the effect and toxicity of eplerenone
Ergotamine Possible ergotism and severe ischemia with this combination
Erlotinib This CYP3A4 inhibitor increases levels/toxicity of erlotinib
Imatinib The macrolide increases levels of imatinib
Felodipine Pfizer-e increases the effect of felodipine
Fluoxetine Possible serotoninergic syndrome with this combination
Gefitinib This CYP3A4 inhibitor increases levels/toxicity of gefitinib
Grepafloxacin Increased risk of cardiotoxicity and arrhythmias
Itraconazole The macrolide increases the effect and toxicity of itraconazole
Levofloxacin Increased risk of cardiotoxicity and arrhythmias
Mesoridazine Increased risk of cardiotoxicity and arrhythmias
Methylergonovine Possible ergotism and severe ischemia with this combination
Lovastatin The macrolide possibly increases the statin toxicity
Methylprednisolone The macrolide increases the effect of corticosteroid
Methysergide Possible ergotism and severe ischemia with this combination
Midazolam The macrolide increases the efect of the benzodiazepine
Moxifloxacin Increased risk of cardiotoxicity and arrhythmias
Oxtriphylline The macrolide increases the effect and toxicity of theophylline
Pimozide Increased risk of cardiotoxicity and arrhythmias
Quetiapine This macrolide increases the effect/toxicity of quetiapine
Quinidine Increased risk of cardiotoxicity and arrhythmias
Quinidine barbiturate Increased risk of cardiotoxicity and arrhythmias
Quinupristin This combination presents an increased risk of toxicity
Ranolazine Increased levels of ranolazine - risk of toxicity
Repaglinide This macrolide increases effect of repaglinide
Rifabutin The rifamycin decreases the effect of the macrolide
Rifampin The rifamycin decreases the effect of the macrolide
Ritonavir Increased toxicity of both agents
Sertraline Possible serotoninergic syndrome with this combination
Sibutramine Pfizer-e increases the effect and toxicity of sibutramine
Sildenafil The macrolide increases the effect and toxicity of sildenafil
Simvastatin The macrolide possibly increases the statin toxicity
Sirolimus The macrolide increases sirolimus levels
Sotalol Increased risk of cardiotoxicity and arrhythmias
Sparfloxacin Increased risk of cardiotoxicity and arrhythmias
Tacrolimus Pfizer-e increases the effect and toxicity of tacrolimus
Terfenadine Increased risk of cardiotoxicity and arrhythmias
Theophylline The macrolide increases the effect and toxicity of theophylline
Thioridazine Increased risk of cardiotoxicity and arrhythmias
Verapamil Increased risk of cardiotoxicity and arrhythmias
Triazolam The macrolide increases the effect of the benzodiazepine
Vardenafil The macrolide increases the effect and toxicity of vardenafil
Vinblastine Pfizer-e increases vinblastine toxicity
Warfarin The macrolide increases anticoagulant effect
Zafirlukast Pfizer-e decreases the effect of zafirlukast
Ergonovine Possible ergotism and severe ischemia with this combination
Everolimus The macrolide increases everolimus levels/toxicity
Lincomycin Possible antagonism of action with this combination
Acenocoumarol The macrolide increases anticoagulant effect
Food Interactions: Avoid alcohol.
Take on empty stomach: 1 hour before or 2 hours after meals.
Take with a full glass of water Avoid taking with grapefruit juice.
Generic Name: Erythromycin
Synonyms: Erythromycin estolate; Erythromycin ethylsuccinate; Erythromycin glucoheptonate; Erythromycin lactobionate; Erythromycin oxime; Erythromycin Stearate; Erythrocin Stearate; Erythrocin; EM
Drug Category: Anti-Bacterial Agents
Drug Type: Small Molecule; Approved
Other Brand Names containing Erythromycin: Abboticin; Abomacetin; Ak-mycin; Akne-Mycin; Aknin; Benzamycin; Benzamycin Pak; Bristamycin; Dotycin; Dumotrycin; E-Base; E-Glades; E-Mycin; E-Solve 2; EMU; ETS; Emgel; Eritrocina; Ermycin; Ery-Sol; Ery-Tab; Eryc; Eryc 125; Eryc Sprinkles; Erycen; Erycette; Erycin; Erycinum; Eryderm; Erygel; Erymax; Erypar; Erythra-Derm; Erythro; Erythro-Statin; Erythrogran; Erythroguent; Erythromast 36; Erythromid; Erythromycin A; Erythromycin B; Ethril 250; Ilocaps; Ilosone; Ilotycin; Ilotycin Gluceptate; IndermRetcin; Kesso-Mycin; Mephamycin; Pantomicina; Pce; Pfizer-e; Propiocine; R-P Mycin; Robimycin; Sansac; Serp-AFD; Stiemycin; Taimoxin-F; Theramycin Z; Torlamicina; Wemid; Wyamycin S;
Absorption: Orally administered erythromycin base and its salts are readily absorbed in the microbiologically active form. Topical application of the ophthalmic ointment to the eye may result in absorption into the cornea and aqueous humor.
Toxicity (Overdose): Symptoms of overdose include diarrhea, nausea, stomach cramps, and vomiting.
Protein Binding: Erythromycin is largely bound to plasma proteins, and the freely dissociating bound fraction after administration of erythromycin base represents 90% of the total erythromycin absorbed.
Biotransformation: Hepatic. Extensively metabolized - after oral administration, less than 5% of the administered dose can be recovered in the active form in the urine.
Half Life: 1.5 hours
Dosage Forms of Pfizer-e: Powder, for solution Oral
Powder, for suspension Oral
Powder, for solution Intravenous
Capsule, coated Oral
Chemical IUPAC Name: (3R,4S,5S,6R,7R,9R,11R,12R,13S,14R)-6-[(2S,3R,4S,6R)-4-dimethylamino-3-hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-7,12,13-trihydroxy-4-[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-3,5,7,9,11,13-hexamethyl-1-oxacyclotetradecane-2,10-dione
Chemical Formula: C37H67NO13
Erythromycin on Wikipedia: https://en.wikipedia.org/wiki/Erythromycin
Organisms Affected: Enteric bacteria and other eubacteria