Arcanobacterium Haemolyticum Medication

Updated: Mar 14, 2022
  • Author: Nicole Ufkes; Chief Editor: William D James, MD  more...
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Medication Summary

No controlled trials of antimicrobial therapy have been conducted for pharyngitis caused by A. haemolyticum. Many patients with pharyngitis have been treated with 1 dose of intramuscular penicillin or 7-10 days of erythromycin or oral penicillin. [5] Antibiotic sensitivity testing reveals that most strains are resistant to trimethoprim-sulfamethoxazole; tetracycline resistance has been observed in 30% of strains tested. [22, 71] An isolate reported in 2006 was also resistant to ciprofloxacin. [45] Virtually all strains of A. haemolyticum studied so far are sensitive to erythromycin, azithromycin, gentamicin, and clindamycin. [22, 72] The majority of isolates are susceptible to penicillin, although tolerance has been reported. Accordingly, macrolides are now considered the drugs of choice. [5, 6, 58]

Penicillin treatment failures also may be related to the ability of A. haemolyticum to invade HEp-2 cells (immortalized upper respiratory epithelial cells) and survive there for 4 days, thus creating an intracellular reservoir of bacteria. [59] Macrolides achieve much higher intracellular concentrations than penicillin. [59, 73, 74]

More serious systemic infections have been treated successfully with high-dose intravenous beta-lactams (eg, penicillin, ampicillin, amoxicillin, cefuroxime, cefotaxime). Vancomycin is also an acceptable choice for serious infections; however, 1 strain carries the vanA gene, which is resistant to vancomycin. [75] Antibiotic selection should be based on antibiotic sensitivity testing because no clinical trials of treatment of systemic infections have been conducted.



Class Summary

Although antibiotic therapy decreases the duration of symptoms, whether it prevents sequelae of pharyngeal infection is not known.

Erythromycin ethylsuccinate (E.E.S., EryPed)

Erythromycin inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, arresting RNA-dependent protein synthesis. It is for the treatment of staphylococcal and streptococcal infections.

In children, age, weight, and severity of infection determine proper dosage. When twice-daily dosing is desired, half of the total daily dose may be taken every 12 hours. For more severe infections, double the dose. While no controlled studies have been performed, erythromycin has been effective in case series and most strains are susceptible.

Azithromycin (Zithromax)

Azithromycin acts by binding to the 50S ribosomal subunit of susceptible microorganisms and blocks dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Nucleic acid synthesis is not affected. It concentrates in phagocytes and fibroblasts as demonstrated by in vitro incubation techniques. In vivo studies suggest that concentration in phagocytes may contribute to drug distribution to inflamed tissues. Azithromycin treats mild-to-moderate microbial infections. A shorter course and daily dosing make this a good alternative for patients who are sensitive to penicillin.

Clindamycin (Cleocin)

Clindamycin is a semisynthetic antibiotic produced by the 7(S)-chloro-substitution of 7(R)-hydroxyl group of the parent compound lincomycin. It inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. It widely distributes in the body without penetration of the CNS. Clindamycin is protein bound and is excreted by the liver and kidneys.

It is an oral or parenteral antibiotic for anaerobic or susceptible streptococcal, pneumococcal, or staphylococcal species. It is considered to have good absorption into the bloodstream in both oral and parental forms.