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Streptococcal Sore Throat

Anas Bahnassi PhD

Pharmacotherapy of Infectious Diseases

Anas Bahnassi 2014

A Case-Based Approach

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hGoals of Therapy

• Provide symptomatic relief.

• Prevent suppurative complications, e.g. mastoiditis, cervical lymphadentitis.

• Prevent nonsuppurative commplications, e.g. acute rheumatic fever.

• Prevent spread of group A streptococci to contacts.

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hInvestigations

• Culturing group A streptococci is needed in a child:

– > 3 year old.

– Acute sore throat.

– Lacks signs of viral URT infection.

– Has the sore throat symptoms.

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InvestigationsClinical Diagnosis of Streptococcal Throat

• Adenitis.• Positive throat cultures.

Although not diagnostic:• Signs: tender cervical adenopathy, erythematous

pharynx and tonsils, pharyngeal exudate, excoriated nares, scarlatiniform rash.

• Symptoms: sore throat, pain on swallowing, headache, abdominal pain, nausea, vomiting, and feer.

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hLaboratory Diagnosis

• Throat culture “Gold Standard” results in 24-48 hrs.

• Repeat cultures are not necessary in asymptomatic patients.

• Antigen screening of throat secretion is fast (7-70 mins) but sensetivity (<90%). Too low to rule out streptococcal infection in children and adolescents.

• If Antigen screening is negative or unavailable:– Hold antibiotics for 48hrs

– Perform throat culture.

– This procedure does not increase the chance of rheumatic fever but avoids the unnecessary use of antibiotics.

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hSelected Pathogens of Acute Pharyngitis:

• Viruses: (Adenoviruses, cytomegalovirus, Epistein=Barr, enteroviruses, influenza, herpes simplex virus, and parainfluenza virus)

• Group A β-hemolytic streptococci (children 15-30%, Adults 5-10%)

• Group C and G β-hemolytic streptococci.• Neisseria gonorrheae (consider child abuse).• Mycoplasma pneumoniae.• Chlamydia trachomatis.• Chlamydophila pneumoniae.• Corynebacterium diphtheriae.• Archanobacterium hemolyticum.

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hManagement of Acute Pharyngitis

Anas Bahnassi 2014

Acute Sore ThroatClinical Assessment

Signs and Symptoms of Group A Streptococcal Pharyngitis

Rapid Antigen Test Throat Culture Immediate investigation not essential, but

diagnosis of streptococcal pharyngitis not ruled out

+ve -ve +ve -ve

Antibiotic and Symptomatic Treatment

Symptomatic Treatment Only

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Therapeutic ChoicesNonpharmacologic

• Strict handwashing to prevent spread of infection.

• Exclude from school or daycare for 24 hours after antimicrobial therapy is begun.

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Therapeutic ChoicesPharmacologic

• Analgesics:– APAP.

– Ibuprofen.

– Lozenges, gargles, etc…

• Antibiotics:– Antibiotic therapy for group A streptococcal pharyngitis can shorten

the course of acute illness and prevent both suppurativenonsuppurative complications if started early in the illness.

– Penicillin is the DRUG of CHOICE.

– Cephalosporins are effective but should not replace penicillin.

– Amoxicillin suspension is more palatable than penicillin for children.

– Erythromycin can be used for patients with penicillin allergies.

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Antibiotic Treatment Recommendations

Anas Bahnassi 2014

Class Drug Dose ADR Comments Cost

Cephalo-sporins

Cefadroxil Adults:1g/day as a single dose or BID X10d

Hyper-sensitivity

Use if treatment with Penicillin fails

$$$

Cefixime Adults and Children >12yrs400mg/d X10days

Children 6m-12yrs8mg/kg/d X10days

Hyper-sensitivity

Use if treatment with Penicillin fails

Available in suspension.

$$$$

Cephalexin Adults:250mg QID X10d

Children:25-50mg/kg/day divided QID X10d

Hyper-sensitivity

Use if treatment with Penicillin fails

Available in suspension.

$

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Antibiotic Treatment Recommendations

Anas Bahnassi 2014

Class Drug Dose ADR Comments Cost

Cephalo-sporins

Cefprozil Adults and Children>12yrs500mg/d X10days

Children 6m-12yrs15mg/kg/d divided

BID

Hyper-sensitivity

Use if treatment with Penicillin fails

Available in suspension.

$$$$

Cefuroxime Adults and Children>12yrs250mg BID X10days

Children 3m-12yrs20mg/kg/d divided BIDX10days

Hyper-sensitivity

Use if treatment with Penicillin fails

Available in suspension.

Add milk or juice prior to dose.

$$

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Antibiotic Treatment Recommendations

Anas Bahnassi 2014

Class Drug Dose ADR Comments Cost

Ketolides Telithromycin Adults 800mg/day once X5days

Diarrhea Use if treatment with β-lactam fails

Telithromycin: Atorvastatin,Lovastatin, Simvastatin, Itraconazole, Ketoconazole.

Digoxin levels.

Contraindicated with ergot, pimozide and disopyramide.

$$$$

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Antibiotic Treatment Recommendations

Anas Bahnassi 2014

Class Drug Dose ADR Comments Cost

Linco-semides

Clindamycin Adults 600mg/day BID-QID X10 days

Children20-30mg/kg/dayDivided TID X10 days

Diarrhea

C.Difficile

Alternative to Erythomycin

Maybe used in symptomatic patients with multiple pharyngitis

Available in suspension.

$$$$

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Antibiotic Treatment Recommendations

Anas Bahnassi 2014

Class Drug Dose ADR Comments Cost

Macro-lides

Azithromycin Adults 500mg on day 1then 250 on days 2-5

Children12mg/kg/dayX 5 days.

Lower GI effects than Eryth.

Available in susp.

Less likely to interact with other meds.

$$

Clarithromycin Adults 250mg BID X10d days

Children15mg/kg/dayDivided Bid X 10 days.

Lower GI effects than Eryth.

Available in susp.

Clarithromycin: Atorvastatin,Lovastatin, Simvastatin, prednisone, theophylline.

$$

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Antibiotic Treatment Recommendations

Anas Bahnassi 2014

Class Drug Dose ADR Comments Cost

Macro-lides

Erythromycin Adults 1g/d divided BID-QID X10d1hr prior meals to prevent interactions.

Nausea, vomiting, epigastricdistress, diarrhea, elevated liver enzymes, cholestaticjaundice.

Alternative to penicillin.

Clarithromycin: Atorvastatin,Lovastatin, Simvastatin, prednisone, theophylline.

$$

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Antibiotic Treatment Recommendations

Anas Bahnassi 2014

Class Drug Dose ADR Comments Cost

Penicillin Amoxicillin 40mg/kg/d divided BID-TID X10days

Well tolerated

Available in chewable andsuspension

$$

Penicillin Adults: 330mg TID or 600mg BID X 10 days.Children: 25-50mg/kg/d divided BID

AnaphylaxisGI distressDiarrhea.

DRUG of Choice $

Amox/Clav Adults: 500mg BID X10 daysChildren: 40mg/kg/d divided TID

GI distressDiarrhea.

Maybe used in symptomatic patients with multiple pharyngitis

Available in suspension.

$$

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hTherapeutic Tips

• Early institution of antibiotic therapy shortens the duration of fever, cervical adenitis, pharyngeal infections, and hastens the overall clinical improvement.

• Early treatment can hasten the return of children to school and reduce the number of days out of work.

• Since there is no efficient way to differentiate acutely infected child and carrier of group A streptococci, all systemic patients with positive culture should be treated.

• Unfortunately Penicillin (Drug of Choice of Acute pharangitis) often fails to eradicate pharyngeal streptococcal carriage, Some advocate the use of clindamycin (20mg/kg/d TID X10d max 600mg/d) or the addition of rifampin (20mg/kg/d TID X10d max 600mg/d) for the final 4 days of penicillin therapy.

Anas Bahnassi 2014

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Pharmacotherapy:Infectious Diseases:

Anas Bahnassi PhD

abahnassi@gmail.com

http://www.twitter.com/abpharm

http://www.facebook.com/pharmaprof

http://www.linkedin.com/in/abahnassiAnas Bahnassi 2014