Intravenous Respiratory tract infections, Skin and soft tissue infections
Adult: Usual dose: 500 mg 12 hourly given via infusion over 60 minutes for 2-5 days, then switch to oral clarithromycin therapy whenever possible.
Oral Respiratory tract infections, Skin and soft tissue infections
Adult: Usual dose: As conventional tab: 250 mg bid, may be increased to 500 mg bid for severe infections. As modified-release tab: 500 mg once daily, may be increased to 1,000 mg daily for severe infections. Usual treatment duration: 7-14 days. Child: <12 years As oral susp: Recommended dose: 7.5 mg/kg bid, up to Max 500 mg bid. Usual treatment duration: 5-10 days, depending on the pathogen involved and severity of infection. Dosage requirements may vary based on patient age and weight (refer to detailed product guideline). ≥12 years Same as adult dose.
Oral Mycobacterium avium complex infections
Adult: Treatment of disseminated cases in patients with advanced HIV infection in combination with other antimycobacterial agents: As conventional tab or oral susp: 500 mg 12 hourly, may continue therapy if clinical response is observed. May discontinue therapy if the patient is at low risk of disseminated infection. Child: Treatment of disseminated cases in patients with advanced HIV infection in combination with other antimycobacterial agents: As conventional tab or oral susp: 7.5 mg/kg 12 hourly, up to 500 mg 12 hourly.
Oral Eradication of Helicobacter pylori associated with peptic ulcer disease
Adult: As conventional tab: Triple therapy regimen in combination with another antibiotic (e.g. metronidazole, amoxicillin) and a PPI (e.g. omeprazole, lansoprazole): 500 mg bid for 7-14 days. Dual therapy regimen in combination with omeprazole: 500 mg tid for 14 days, followed by omeprazole for an additional 14 days.
Special Patient Group
Patients with renal impairment concurrently taking atazanavir, or ritonavir-containing regimens:
CrCl (mL/min)
Dosage
30-60
Reduce dose by 50%. Max: 1,000 mg/day.
<30
Reduce dose by 75%. Max: 1,000 mg/day.
Renal Impairment
Oral: Respiratory tract infections; Skin and soft tissue infections:
CrCl (mL/min)
Dosage
<30
As conventional tab: Reduce to half of the usual dose. As modified-release tab: Contraindicated.
Eradication of H. pylori associated with peptic ulcer disease; Mycobacterium avium complex infections:
CrCl (mL/min)
Dosage
<30
Reduce to half of the usual dose.
Intravenous:
CrCl (mL/min)
Dosage
<30
Reduce to half of the usual dose.
Administration
standard release tab & oral susp: May be taken with or without food. XL & MR tab: Should be taken with food. Swallow whole, do not chew/crush.
Reconstitution
Powder for oral susp: Reconstitute with the appropriate volume of water as indicated on the label. Shake well until suspended. Powder for IV infusion: Reconstitute a vial labelled as 500 mg with 10 mL of sterile water for inj. Further add the reconstituted solution to at least 250 mL of compatible diluent (e.g. 5% dextrose in Lactated Ringer’s solution, 5% dextrose, 0.9% NaCl, Lactated Ringer’s, 5% dextrose in 0.3% NaCl, 5% dextrose in 0.45% NaCl) to make a final concentration of approx 2 mg/mL.
Contraindications
Hypersensitivity to clarithromycin or any macrolide antibiotics. History of cholestatic jaundice/hepatic dysfunction associated with previous clarithromycin use; hypokalaemia, history of QT prolongation (congenital or documented acquired), ventricular cardiac arrhythmia including torsades de pointes; severe hepatic failure in combination with renal impairment. Concomitant use with ergot alkaloids (e.g. ergotamine, dihydroergotamine), oral midazolam, astemizole, cisapride, domperidone, pimozide, terfenadine, ticagrelor, ranolazine, lovastatin, simvastatin, colchicine, lomitapide. Modified-release tab: Significant renal impairment (CrCl <30 mL/min).
Special Precautions
Patient with coronary artery disease, severe cardiac insufficiency, clinically relevant bradycardia or conduction disturbances; electrolyte disturbances (e.g. hypomagnesaemia), myasthenia gravis. Patient taking other drugs known to prolong QT interval (e.g. class IA or III antiarrhythmics, antipsychotic agents, antidepressants, fluoroquinolones). Patient with renal impairment concurrently taking atazanavir or ritonavir-containing regimens. Hepatic and moderate to severe renal impairment. Children. Pregnancy and lactation.
Adverse Reactions
Significant: Hepatic dysfunction (e.g. increased liver enzymes, hepatocellular and/or cholestatic hepatitis with or without jaundice); exacerbation or new onset of myasthenia gravis. Gastrointestinal disorders: Abdominal pain, diarrhoea, nausea, vomiting, dysgeusia, dyspepsia. General disorders and administration site conditions: Inj site reactions (e.g. phlebitis, pain, inflammation). Infections and infestations: Candidiasis. Investigations: Prolonged prothrombin time, increased BUN. Nervous system disorders: Headache. Psychiatric disorders: Insomnia. Skin and subcutaneous tissue disorders: Rash, hyperhidrosis. Vascular disorders: Vasodilation (IV). Potentially Fatal: Hepatic failure, pseudomembranous colitis or C. difficile-associated diarrhoea (CDAD); QT prolongation, arrhythmias including torsades de pointes; anaphylaxis, severe cutaneous adverse reactions (e.g. acute generalised exanthematous pustulosis, Stevens-Johnson syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms, Henoch-Schonlein purpura or IgA vasculitis).
Perform culture and susceptibility tests; consult local institutional recommendations before treatment initiation due to antibiotic resistance risks. Monitor BUN and serum creatinine; CBC with differential.
Overdosage
Symptoms: Abdominal pain, vomiting, nausea, and diarrhoea. Management: Supportive treatment. Initiate prompt elimination of unabsorbed drugs.
Drug Interactions
May result in significant hypoglycaemia with oral hypoglycaemics (e.g. sulfonylureas, repaglinide, nateglinide) and insulin. Increased risk of haemorrhage and elevated INR and prothrombin time with warfarin. May induce metabolism and decrease efficacy with CYP3A inducers (e.g. rifampicin, phenytoin, carbamazepine, phenobarbital). May reduce the plasma levels with strong CYP450 inducers (e.g. efavirenz, nevirapine, rifabutin, rifapentine). Decreased exposure with etravirine. Increased plasma concentration and exposure with fluconazole. May elevate the serum concentrations of digoxin and CYP450 substrates (e.g. alprazolam, carbamazepine, cilostazol, ciclosporin, methylprednisolone, omeprazole, quetiapine, sildenafil, sirolimus, tacrolimus, vinblastine, theophylline, valproate, tolterodine). May increase the risk of torsades de pointes with quinidine or disopyramide. May decrease the plasma concentrations of zidovudine. Ritonavir significantly inhibits the metabolism of clarithromycin. Concomitant use with atazanavir, itraconazole, saquinavir, or certain Ca channel blockers (e.g. verapamil, amlodipine, diltiazem) may result in bi-directional drug interactions. Increased or prolongation of sedation with triazolam. Potentially Fatal: Concomitant use with cisapride, pimozide, domperidone, terfenadine, and astemizole may cause QT prolongation or cardiac arrhythmias including ventricular tachycardia or fibrillation, and torsades de pointes. Increased serum concentrations and risk of acute toxicity of ergotamine or dihydroergotamine. Markedly elevated plasma concentrations of oral midazolam. Significantly increased transaminases with lomitapide. Increased risk of myopathy and rhabdomyolysis with lovastatin or simvastatin. Increased serum levels and risk of toxicity of colchicine. May increase serum concentrations of ranolazine; decrease serum concentrations of the active metabolite of ticagrelor.
Food Interaction
May reduce the efficacy with St. John’s wort.
Action
Description: Mechanism of Action: Clarithromycin is a macrolide antibiotic that selectively binds to the 50S ribosomal subunit of susceptible bacteria and prevents the activated amino acids translocation, resulting in inhibition of intracellular protein synthesis. Pharmacokinetics: Absorption: Rapidly and well absorbed from the gastrointestinal tract. Bioavailability: Approx 50%. Time to peak plasma concentration: 2-3 hours (immediate-release); 5-8 hours (modified-release). Distribution: Widely and readily distributed into most body tissues and fluids. Crosses the placenta and enters breast milk. Plasma protein binding: 80%. Metabolism: Partially metabolised in the liver by CYP3A4 isoenzyme and undergoes extensive first-pass metabolism into 14-hydroxyclarithromycin (active). Excretion: Via urine (approx 20-40% as unchanged drug; 10-15% as metabolites); faeces (5-10% as unchanged drug). Elimination half-life: Immediate-release: 3-7 hours (clarithromycin); 5-9 hours (14-hydroxyclarithromycin).
Chemical Structure
Clarithromycin Source: National Center for Biotechnology Information. PubChem Database. Clarithromycin, CID=84029, https://pubchem.ncbi.nlm.nih.gov/compound/Clarithromycin (accessed on Jan. 21, 2020)
Storage
Conventional/modified-release tab: Store between 15-30°C. Protect from light. Oral susp: Store at 25°C prior to and after reconstitution. Do not refrigerate. Once reconstituted, use within 14 days. Powder for IV infusion: Store below 30°C.
Sign Out
