Dosing & Uses
Dosing Form & Strengths
tablet
- 250mg
- 500mg
General Dosing Recommendations
250 mg PO q6hr, OR
500 mg PO q12hr (if daily dose does not exceed 1 g)
May increase up to 4 g/day depending on infection severity
Amebiasis
500 mg PO q6hr for 10-14 days
Legionnaires Disease
1-4 g/day PO in divided doses for 21 days
Urethritis
Urethritis caused by C trachomatis or U urealyticum
500 mg PO q6hr for 7 days; alternatively 333 mg PO q8hr for 7 days
Syphilis
30-40 g PO in divided doses for 10-15 days
Renal Impairment
Dose adjustment not necessary
Hepatic Impairment
Use caution
Other Indications & Uses
Group A beta-hemolytic strep, Actinobacillus actinomycetemcomitans, Actinomyces israelii, Actinomyces naeslundii, Actinomyces odontolyticus, Afipia felis, Arachnia propionica, Arcanobacterium (Corynebacterium) haemolyticum, Bacillus anthracis, Bartonella henselae, Bartonella quintana, Bordetella pertussis, Borrelia burgdorferi, Borrelia recurrentis, C. diphtheriae, C. trachomatis, Klebsiella granulomatis, Campylobacter jejuni, Capnocytophaga ochracea, Chlamydia pneumonia (TWAR agent), Chlamydia psittaci, Chlamydia trachomatis, Chryseobacterium meningosepticum, Corynebacterium jeikeium (CDC group JK), Corynebacterium minutissimum, Corynebacterium ulcerans, Coxiella burnetii, E. histolytica, Erysipelothrix rhusiopathiae, H. ducreyi, H. influenzae, Kingella sp., Lactobacillus sp, Legionella pneumophilia, Leptospira interrogans, Leptotrichia buccalis, Leuconostoc species, Listeria, Mycobacterium chelonae, Mycobacterium fortuitum, M. catarrhalis, Mycoplasma pneumoniae, N. gonorrhoeae, Rhodococcus equi, S. aureus, S. pyogenes (group A beta-hemolytic streptococci), S. pneumoniae, Spirillum minus, Streptobacillus moniliformis, Streptococcus (Group C, G), Streptococcus agalactiae (Group B), Streptococcus bovis (Group D), Streptococcus intermedius group (S. anginosus, S intermedius, S. constellatus), Streptococcus pneumoniae (PCN sensitive, MIC <0.1 mcg/mL), Streptococcus pyogenes (Group A), Treponema pallidum, U. urealyticum, Ureaplasma urealyticum, Vibrio cholerae, Viridans streptococci
Off-label: Campylobacter jejuni, Calymmatobacterium granulomatis, Haemophilus ducreyi, prophylaxis in colorectal surgery, anthrax, tetanus, Lyme disease
First line: Afipia felis, Arcanobacterium (Corynebacterium) haemolyticum, Bartonella henselae, Bartonella quintana, Campylobacter jejuni, Capnocytophaga ochracea, Chlamydia pneumonia, Corynebacterium minutissimum, Corynebacterium ulcerans, Haemophilus ducreyi, Mycobacterium fortuitum, Ureaplasma urealyticum (others eg, Haemophilus ducreyi not unanimous)
Dosing Form & Strengths
tablet
- 250mg
- 500mg
General Dosing Recommendations
Mild-to-moderate infections: 30-50 mg/kg/day PO divided q6-8hr
Severe infection: 60-100 mg/kg/day PO divided q6-8hr
Not to exceed 4 g/day
Intestinal Amebiasis
30-50 mg/kg/day PO in divided doses for 10-14 days
Pneumonia of Infancy
50 mg/kg/day PO divided q6hr for at least 3 weeks
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Adverse Effects
1-10%
Abdominal pain (8%)
Headache (8%)
Nausea (8%)
Diarrhea (7%)
Rash (3%)
Vomiting (3%)
Dyspepsia (2%)
Flatulence (2%)
Pain (2%)
Pruritus (1%)
Pseudomembranous colitis
Hypertrophic pyloric stenosis
Anaphylaxis
Fever
Mild allergic reactions
Urticaria
Skin eruptions
Tinnitus
<1%
Cholestatic hepatitis
Confusion
Hallucinations
Hearing loss
Hypotension
Nervous system effects including seizures
Torsade de pointes
Ventricular tachycardia
Vertigo
Postmarketing reports
Interstitial nephritis
Warnings
Contraindications
Documented hypersensitivity
History of hepatitis caused by macrolide, cholestatic hepatitis, or hepatic impairment
Coadministration with cisapride or pimozide
Coadministration with ergotamine or dihydroergotamine (postmarketing reports of acute ergot toxicity characterized by vasospasm and ischemia of the extremities and other tissues including the central nervous system)
Coadministration with HMG CoA reductase inhibitors (statins) that are extensively metabolized by CYP3A4 (lovastatin or simvastatin), owing to the increased risk of myopathy, including rhabdomyolysis
Cautions
Risk of sudden death due to cardiac causes w/ concomitant use of oral erythromycin w/ drugs that inhibit CYP3A4
Erythromycin is considered a moderate inhibitor of CYP3A4; may increase toxicity of CYP3A4 substrates
Colchicine is a substrate for both CYP3A4 and the efflux transporter P-glycoprotein (P-gp); significant increase in colchicine plasma concentration is anticipated when coadministered with moderate CYP3A4 inhibitors; reduce the starting dose of colchicine and lower maximum colchicine dose
Caution in liver disease; estolate formulation may cause cholestatic jaundice; GI side effects are common (give doses pc); discontinue use if nausea, vomiting, malaise, abdominal colic, or fever occur
Ventricular arrhythmias
Associated with QT prolongation and infrequent cases of arrhythmia
May increase LFTs in pregnant women
GI effects: Abdominal pain and cramping; diarrhea; nausea and vomiting Hepatic impairment
Overgrowth of nonsusceptible bacteria or fungi
Pregnancy & Lactation
Pregnancy Category: B
Lactation: distributed in breast milk, use with caution; AAP categorizes as compatible with breastfeeding
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest
Absorption
Oral: variable but better with salt forms than with base form
Peak Plasma Time: 4 hr (base)
Distribution
Protein Bound: 75-80%
Crosses placenta; enters breast milk
Relative diffusion from blood into CSF: minimal even with inflammation
Metabolism
Via P450 enzyme CYP3A4
Enzymes inhibited: CYP1A2, CYP3A4
Elimination
Half-Life: 1.4 hr
Excretion: Primarily feces; urine (2-15% as unchanged drug)
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Patient Handout
Formulary
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