Clarithromycin

clarithromycin

(klar ith' ro my sin)

Biaxin, Biaxin XL

Pregnancy Category C

Drug class

Macrolide antibiotic

Therapeutic actions

Inhibits protein synthesis in susceptible bacteria, causing cell death.

Indications

·        Treatment of URIs caused by Streptococcus pyogenes, S. pneumoniae

·        Treatment of lower respiratory infections caused by Mycoplasma pneumoniae, S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis

·        Treatment of skin and skin-structure infections caused by Staphylococcus aureus, S. pyogenes

·        Treatment of disseminated mycobacterial infections due to Myobacterium avium and M. intracellular

·        Treatment of active duodenal ulcer associated with Helicobacter pylori in combination with proton pump inhibitor

·        Treatment of acute otitis media, acute maxillary sinusitis due to H. influenzae, M. cararrhalis, S. pneumoniae

·        Treatment of mild to moderate community-acquired pneumonia in adults

Contraindications and cautions

·        Contraindicated with hypersensitivity to clarithromycin, erythromycin, or any macrolide antibiotic.

·        Use cautiously with colitis, hepatic or renal impairment, pregnancy, lactation.

Available forms

Tablets—250, 500 mg; granules for suspension—125, 250 mg/5 mL; ER tablets–500 mg

Dosages

ADULTS

·        Pharyngitis, tonsillitis; pneumonia due to S. pneumoniae, M. pneumoniae; skin or skin-structure infections; lower respiratory infections due to S. pneumoniae, M. catarrhalis: 250 mg PO q 12 hr for 7–14 days.

·        Acute maxillary sinusitis, lower respiratory infections caused by H. influenzae: 500 mg PO q 12 hr for 7–14 days.

·        Mycobacterial infections: 500 mg PO bid.

·        Treatment of duodenal ulcers: 500 mg PO tid plus omeprazole 40 mg PO q AM for 14 days, then omeprazole 20 mg PO q morning for 14 days.

·        Treatment of community-acquired pneumonia: 250 mg PO q 12 hr for 7–14 days or 1,000 mg PO of ER tablet q 24 hr for 7 days.

PEDIATRIC PATIENTS

Usual dosage, 15 mg/kg/day PO q 12 hr for 10 days.

·        Mycobacterial infections: 7.5 mg/kg PO bid.

GERIATRIC PATIENTS OR PATIENTS WITH IMPAIRED RENAL FUNCTION

Decrease dosage or prolong dosing intervals as appropriate.

Pharmacokinetics

Route	Onset	Peak
Oral	Varies	2 hr

Metabolism: Hepatic; T_1/2: 3–7 hr

Distribution: Crosses placenta; enters breast milk

Excretion: Urine

Adverse effects

·        CNS: Dizziness, headache, vertigo, somnolence, fatigue

·        GI: Diarrhea, abdominal pain, nausea, dyspepsia, flatulence, vomiting, melena, pseudomembranous colitis

·        Other: Superinfections, increased PT, decreased WBC

Interactions

Drug-drug

·        Increased serum levels and effects of carbamazepine, theophylline, lovastatin, phenytoin

Drug-food

·        Food decreases the rate of absorption of clarithromycin but does not alter effectiveness

·        Decreased metabolism and risk of toxic effects if combined with grapefruit juice; avoid this combination.

Nursing considerations

Assessment

·        History: Hypersensitivity to clarithromycin, erythromycin, or any macrolide antibiotic; pseudomembranous colitis, hepatic or renal impairment, lactation, pregnancy

·        Physical: Site of infection; skin color, lesions; orientation, GI output, bowel sounds, liver evaluation; culture and sensitivity tests of infection, urinalysis, LFTs, renal function tests

Interventions

·        Culture infection before therapy.

·        Do not cut or crush, and ensure that patient does not chew ER tablets.

·        Monitor patient for anticipated response.

·        Administer without regard to meals; administer with food if GI effects occur.

Teaching points

·        Take drug with food if GI effects occur. Take the full course of therapy. Do not drink grapefruit juice while taking this drug.

·        Shake suspension before use; do not refrigerate; do not cut, crush, or chew extended-release tablets; swallow them whole.

·        You may experience these side effects: Stomach cramping, discomfort, diarrhea; fatigue, headache (medication may be ordered); additional infections in the mouth or vagina (consult with care provider for treatment).

·        Report severe or watery diarrhea, severe nausea or vomiting, rash or itching, mouth sores, vaginal sores.