amoxicillin/clarithromycin/omeprazole

Adult Dosing

Helicobacter pylori infection with active duodenal ulcer

Amoxicillin 1000 mg plus clarithromycin 500 mg plus omeprazole 20 mg PO, each given twice daily x10 days before meal

Notes:

In patients with an active duodenal ulcer at the time of treatment initiation, an additional 18 days of omeprazole 20 mg qd should be taken for ulcer healing and symptom relief
Amoxicillin, clarithromycin and omeprazole should not be chewed or crushed, but should be swallowed whole

Pediatric Dosing

Safety and effectiveness in pediatric patients have not been established

[Outline]

Adult Dosing
Pediatric Dosing

Indications ⬆ ⬇

Eradication of Helicobacter pylori in patients with active duodenal ulcer or history of duodenal ulcer disease

Contraindications ⬆ ⬇

Hypersensitivity to any of the ingredients of the product
Patients taking ergotamine or dihydroergotamine and pimozide

Black Box Warnings ⬆ ⬇

Dosing Adjustment ⬆ ⬇

Renal Dose Adjustment

Severe renal impairment: Prolonged dosing intervals for the clarithromycin component is recommended

Hepatic Dose Adjustment

Hepatic impairment: Avoid use

Warnings/Precautions ⬆ ⬇

See Supplemental Patient Information

Avoid use in pregnant women except in clinical circumstances where there is no alternate therapy and when the potential benefit to the patient outweighs the potential risk to the fetus. If pregnancy occurs during therapy, patients should be cautioned about the potential hazard to the fetus
Clostridium difficile associated diarrhea (CDAD), ranging in severity from mild diarrhea to fatal colitis, may occur; treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C.difficile
If CDAD is suspected/confirmed, discontinue treatment and provide fluid, electrolyte, and protein supplementation along with antibiotics for C. difficile and institute surgical evaluation as clinically indicated
Prescribing antibiotics in the absence of proven or strongly suspected bacterial infection or a prophylactic indication increases the risk of development of drug-resistant bacteria
New onset or exacerbation of symptoms of myasthenia gravis has been reported in patients receiving clarithromycin therapy
Concomitant use of clarithromycin and colchicine may cause colchicine toxicity, especially in elderly patients
Symptomatic response to therapy with omeprazole does not preclude the presence of gastric malignancy
Administration of ampicillin-class antibiotics is not recommended in patients with mononucleosis
Superinfections with mycotic or bacterial pathogens may occur during therapy; if superinfections occur, discontinue treatment and institute appropriate therapy

Cautions: Use cautiously in

Severe renal impairment
Risk of QT prolongation
History of diarrhea

Supplemental Patient Information

Advise patients to promptly report their physicians if they develop severe diarrhea with watery and bloody stools

Pregnancy/Breast Feeding ⬆ ⬇

Pregnancy Category:C

Breastfeeding: Amoxicillin is compatible and considered safe with breastfeeding based upon data from AAP Policy Guidelines (available at http://aappolicy.aappublications.org/cgi/content/full/pediatrics;108/3/776 ). As clarithromycin is excreted in breastmilk in low levels and administered directly to infants, it is acceptable in nursing women. Low levels in milk are unlikely to cause adverse effects in breastfed infants. Monitor infants for diarrhea, candidiasis or colitis. Unconfirmed epidemiologic evidence indicates that maternal use of macrolide antibiotics during breastfeeding might increase the risk of hypertrophic pyloric stenosis in infants. Omeprazole would not be expected to cause any adverse effects in breastfed infants. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 3 August 2011). Manufacturer advises caution.

Adverse Reactions ⬆ ⬇

CNS: Headache, dizziness
RESP: Upper respiratory infection, cough
NEURO: Myasthenia gravis, asthenia
GI: CDAD, abdominal pain/discomfort, nausea, diarrhea, vomiting, flatulence, acid regurgitation, constipation, abnormal taste, dyspepsia
DERM: Rash
MUSC: Back pain
HYPERSENSITIVITY: Hypersensitivity reactions

Clinical Pharmacology ⬆ ⬇

Amoxicillin

Bactericidal; inhibits biosynthesis of the cell wall mucopeptide
Extensively metabolized by liver; CYP450: unknown
Primarily excreted in urine (60% excreted unchanged within 6-8 hrs)
Half-life: 61.3 min

Clarithromycin

Macrolide antibiotic; binds to the 50S ribosomal subunit of the bacteria inhibiting the RNA-mediated bacterial protein synthesis
Metabolized in the liver to 14-OH clarithromycin; CYP450: 3A4 substrate
Excreted in urine (20-40% unchanged), feces
Half-life:

Clarithromycin : 3-4 hrs (250 mg), 5-7 hrs (500 mg)
14-OH clarithromycin: 250 mg (5-6 hrs), 500 mg (7-9 hrs)

Omeprazole

Proton pump inhibitor; decreases gastric acid secretion and increases gastric mucus and bicarbonate production, creating protective coating on gastric mucosa and easing discomfort from excess gastric acid
Extensively metabolized in the liver by the cytochrome P450 enzyme
Absolute bioavailability (compared with IV administration): 30-40% at doses of 20-40 mg
Approximately 77% of the drug is eliminated in urine; the remainder is eliminated in the feces
Half-life: 0.5-1 hr (increased in hepatic impairment)

Brands and Availability ⬆ ⬇