Pertussis in Emergency Medicine Medication

The goals of pharmacotherapy are to eradicate the infection, to reduce morbidity, and to prevent complications.

Erythromycin is the antibiotic treatment of pertussis. If the patient is allergic to erythromycin, use trimethoprim sulfamethoxazole (TMP-SMZ).

Class Summary

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.

Erythromycin base (Ilosone, EES)

Erythromycin estolate is antibiotic of choice to prevent interpersonal transfer, because of enhanced absorption, particularly in young infants. Effectiveness of prophylaxis for exposed and susceptible persons not determined; recommended for household and close contacts (50 mg/kg/d PO qid for 14 d). Effective in reducing course and symptoms if started within the first 10-14 d but not proven beyond this period. Inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes, arresting RNA-dependent protein synthesis. For treatment of staphylococcal and streptococcal infections.

Azithromycin (Zithromax)

Acts by binding to 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.

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.

Treats mild-to-moderate microbial infections.

Plasma concentrations are very low, but tissue concentrations are much higher, giving it value in treating intracellular organisms. Has a long tissue half-life.

Shown to be effective for pertussis in several small studies.

Clarithromycin (Biaxin)

Semisynthetic macrolide antibiotic that reversibly binds to P site of 50S ribosomal subunit of susceptible organisms and may inhibit RNA-dependent protein synthesis by stimulating dissociation of peptidyl tRNA from ribosomes, causing bacterial growth inhibition.

Trimethoprim and sulfamethoxazole (TMP-SMZ, Bactrim DS, Septra)

Second-line antibiotic (for erythromycin allergy or intolerability). Inhibits bacterial growth by inhibiting synthesis of dihydrofolic acid. Combination blocks 2 consecutive steps in bacterial biosynthesis of essential nucleic acids and proteins. In vitro, bacterial resistance develops more slowly with combination than with either drug alone.

Class Summary

Active immunization increases resistance to infection. Vaccines consist of microorganisms or cellular components that act as antigens. Administration of the vaccine stimulates the production of antibodies with specific protective properties.

The need for prevention of pertussis through immunization cannot be overemphasized. Children of parents who refuse pertussis immunizations are at high risk for pertussis infection relative to vaccinated children. A case-control study identified 156 laboratory-confirmed pertussis cases over an 11-year period (matched controls n=595).^[5] Among the cases, 18 (12%) were pertussis vaccine refusers and among the controls 3 (0.5%) were vaccine refusers. Children of parents who refused pertussis immunizations were at an increased risk for pertussis compared with children of parents who accepted vaccinations. A secondary case-control analysis confirmed these results. The study was performed within the Kaiser Permanente of Colorado, where 11% of all pertussis cases within the Colorado Kaiser Permanente system were attributed to parental vaccine refusal. Herd immunity does not seem to completely protect unvaccinated children from pertussis.

All children younger than 7 years should receive the pertussis vaccine. In the United States, acellular pertussis vaccine is recommended and usually is combined with diphtheria and tetanus toxoids (DTaP). When possible, the same DTaP vaccine product should be used for the first 5 doses of the pertussis immunization series. Tdap is recommended as a one-time adolescent booster or for adults requiring tetanus immunization who did not have an adolescent booster. Reduced-volume dosing is not recommended. Measurable antibody wanes after 3-5 years and is not measurable 12 years after vaccination has been completed. Vaccine may not prevent the illness entirely, but it has been shown to lessen disease severity and duration.

Adolescents and adults have been identified as the source of pertussis transmission to infants, from household contact studies and outbreak investigations. In February 2012, the CDC Advisory Committee on Immunization Practices (ACIP) recommended the tetanus, diphtheria, and acellular pertussis (Tdap) vaccine for all adults, including those aged 65 years or older, and pregnant women.

In December 2005, the American Academy of Pediatrics approved recommendations from the Committee on Infectious Diseases (COID) for universal vaccination of adolescents at the 11- or 12-year visit to boost protection against pertussis. The Food and Drug Administration (FDA) has licensed 2 tetanus toxoids (Td), reduced diphtheria toxoid and acellular pertussis vaccine (Tdap) products, for use in children aged 10-18 years (Boostrix; GlaxoSmithKline Biologicals, Rixensart, Belgium) and in those aged 11-64 years (Adacel; Sanofi Pasteur, Toronto, Canada).

The latest vaccine recommendations can be found at the CDC Immunization Schedule Website.^[6]

Diphtheria, tetanus and acellular pertussis (DTaP) vaccine (Tripedia, Certiva, Infanrix)

Promotes active immunity to diphtheria, tetanus, and pertussis by inducing production of specific antibodies and antitoxins.

In children and adults, may administer into deltoid or midlateral thigh muscles. In infants, preferred site of administration is the mid thigh laterally.

Tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Adacel, Boostrix)

Tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine. Promotes active immunity to diphtheria, tetanus, and pertussis by inducing production of specific neutralizing antibodies and antitoxins. Indicated for active booster immunization for tetanus, diphtheria, and pertussis prevention for persons aged 10-64 y (Adacel approved for 11-64 y, Boostrix approved for 10-18 y). Preferred vaccine for adolescents scheduled for booster.