And Clarithromycin

Uses

This is used for the eradication of H. pylori in active chronic gastric, duodenal and gastric ulcers.

And Clarithromycin is also used to associated treatment for these conditions: Acute Bacterial Sinusitis (ABS), Acute Otitis Media, Acute Otitis Media (AOM), Bacterial Infections, Community Acquired Pneumonia (CAP), Duodenal ulcer caused by helicobacter pylori, Genitourinary infections, Helicobacter Pylori Infection, Lower Respiratory Tract Infection (LRTI), Peptic Ulcer With H. Pylori Infection, Sinusitis, Skin and Subcutaneous Tissue Bacterial Infections, Urinary Tract Infection, Acute, uncomplicated Gonorrhea, Ear, nose, and throat infectionsAcute Bacterial Exacerbation of Chronic Bronchitis (ABECB), Acute maxillary sinusitis, Bacterial Infections, Bartonellosis, Community Acquired Pneumonia (CAP), Duodenal ulcer caused by helicobacter pylori, Infective Endocarditis, Lyme Disease, Mycobacterial Infections, Otitis Media (OM), Pertussis, Streptococcal Pharyngitis, Streptococcal tonsillitis, Uncomplicated skin and subcutaneous tissue bacterial infectionsGastro-esophageal Reflux Disease (GERD), Gastrointestinal Bleeding, Helicobacter Pylori Infection, Peptic Ulcer Disease, Hypersecretory conditions

How And Clarithromycin works

Amoxicillin competitively inhibits penicillin-binding protein 1 and other high molecular weight penicillin binding proteins. Penicillin bind proteins are responsible for glycosyltransferase and transpeptidase reactions that lead to cross-linking of D-alanine and D-aspartic acid in bacterial cell walls. Without the action of penicillin binding proteins, bacteria upregulate autolytic enzymes and are unable to build and repair the cell wall, leading to bacteriocidal action.

Clarithromycin is first metabolized to 14-OH clarithromycin, which is active and works synergistically with its parent compound. Like other macrolides, it then penetrates bacteria cell wall and reversibly binds to domain V of the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome, blocking translocation of aminoacyl transfer-RNA and polypeptide synthesis. Clarithromycin also inhibits the hepatic microsomal CYP3A4 isoenzyme and P-glycoprotein, an energy-dependent drug efflux pump.

As a PPI, lansoprazole is a prodrug and requires protonation via an acidic environment to become activated. Once protonated, lansoprazole is able to react with cysteine residues, specifically Cys813 and Cys321, on parietal H+,K+-ATPase resulting in stable disulfides. PPI's in general are able to provide prolonged inhibition of acid secretion due to their ability to bind covalently to their targets.

Dosage

And Clarithromycin dosage

One strip twice daily for 7-14 days or as per the physician's advice.

Suspension: Shake the bottle well before adding water. Then add 12 tea spoonful (60 ml) of boiled and cooled water to the bottle and shake well to make 100 ml suspension.

Amoxycillin 500 mg Injection:

• Intramuscular : Add 2.5 ml water for injection to Amoxycillin 500 mg injection vial.
• Intravenous : Dissolve Amoxycillin 500 mg injection in 10 ml water for injection.

This may be given with or without meals.

The usual duration of treatment is 6 to 14 days.

Children older than 12 years: As for adults.

Eradication of H. pylori in patients with duodenal ulcers: Adults: The usual duration of treatment is 6 to 14 days.

45 ml of water is to be added to the granules in the bottle and shaken to yield 70 ml of reconstituted suspension. The concentration of clarithromycin in the reconstituted suspension is 125 mg per 5 ml.

Side Effects

Common side effects may include: diarrhea, constipation; headache; vaginal itching or discharge; nausea, vomiting, stomach pain; unusual or unpleasant taste in the mouth; or discolored teeth, black or "hairy" tongue.

Toxicity

Patients experiencing an overdose may present with hematuria, oliguria, abdominal pain, acute renal failure, vomiting, diarrhea, rash, hyperactivity, and drowsiness. Treat overdose with symptomatic and supportive treatment, which may include emesis or hemodialysis.

Symptoms of toxicity include diarrhea, nausea, abnormal taste, dyspepsia, and abdominal discomfort. Transient hearing loss with high doses has been observed. Pseudomembraneous colitis has been reported with clarithromycin use. Allergic reactions ranging from urticaria and mild skin eruptions to rare cases of anaphylaxis and Stevens-Johnson syndrome have also occurred. Rare cases of severe hepatic dysfunctions also have been reported. Hepatic failure is usually reversible, but fatalities have been reported. Clarithromycin may also cause tooth decolouration which may be removed by dental cleaning. Fetal abnormalities, such as cardiovascular defects, cleft palate and fetal growth retardation, have been observed in animals. Clarithromycin may cause QT prolongation.

The most commonly reported adverse events occurring more frequently in lansoprazole treated patients compared to placebo include abdominal pain, constipation, diarrhea, and nausea. There is a case report of toxic epidermal necrolysis (TEN), which is a rare but very serious cutaneous reaction, caused by lansoprazole. The previously healthy patient presented with symptoms of TEN 15 days after starting lansoprazole to manage peptic disease. Although the use of PPI's is rarely associated with TEN, causation should be considered if a patient presents with TEN shortly after newly commencing a PPI.

In a single case report, a patient ingested 600 mg of lansoprazole and did not experience any adverse effects or symptoms of overdose. Overall, lansoprazole is well tolerated with relatively few adverse effects.

Lansoprazole is classified as Pregnancy Category B. Although there are animal studies that suggest lansoprazole does not cause harm to the fetus, there is still a paucity of human data. Hence, lansoprazole should only be administered to pregnant women if other options with more safety data have been exhausted.

It is unknown if lansoprazole is excreted in human breast milk. It is worth mentioning that lansoprazole has been used safely in infants, and is therefore likely safe to use during breastfeeding.

Precaution

Serious and occasionally fatal hypersensitivity (anaphylactoid) reactions have been reported in patients on Amoxicillin therapy. These reactions are more appropriate to occur in individuals with a history of penicillin hypersensitivity. Clarithromycin should not be used in pregnant women except in clinical circumstances where no alternative therapy is appropriate.

Adverse reactions which were reported as possibly or probably related to treatment (>3%) in clinical trials when all three components of this therapy were given concomitantly are listed below and devided by body systems. Digestive system: Nausea, vomitng, diarrhoea, dark stools, dry mouth, glossitis, oral moniliasis, stomatitis, tongue discoloration ; Musculoskeletal System - myalgia; Nervous System - confusion, headache, dizziness; Skin- skin reactions; Urogenital System - vaginitis, vaginal moniliasis.

Interaction

Lansoprazole is metabolized through the cytochrome P450 system, specially through the CYP3A and CYP2C19 isozymes. Studies in healthy subjects have shown that Lansoprazole does not have clinically significant interactions with other drugs metabolized by the cytochrome P450 system, such as warfarin, antipyrine, indomethacin, ibuprofen, phenytoin, propranolol, prednisolone, diazepam, clarithromycin orterfenadine.

Clarithromycin use in patients who are receiving theophylline may be associated with increase of serum theophylline concentrations.

There have been reports of interactions of erythromycin and/or clarithromycin with carbamazepine, cyclosporine, tacrolimus, hexobarbital, phenytoin, alfetanil, disopyramide, lovastatin, bromocriptine, valproate, terfenadine, cisapride, pimozide & astemizole.

Volume of Distribution

The central volume of distribution of amoxicillin is 27.7L.

The apparent volume of distribution of lansoprazole is 0.4 L/kg.

Elimination Route

Amoxicillin is approximately 60% bioavailable. A 250mg dose of oral amoxicillin reaches a C_max 3.93±1.13mg/L with a T_max 1.31±0.33h and an AUC of 27.29±4.72mg*h/L. A 875mg dose of oral amoxicillin reaches a C_max 11.21±3.42mg/L with a T_max 1.52±0.40h and an AUC of 55.04±12.68mg*h/L.

Clarithromycin is well-absorbed, acid stable and may be taken with food.

The oral bioavailability of lansoprazole is reported to be 80-90% and the peak plasma concentration(Cmax) is achieved about 1.7 hours after oral dosing. Food reduces the absorption of lansoprazole (both Cmax and AUC are reduced by 50-70%); therefore, patients should be instructed to take lansoprazole before meals.

Half Life

The half life of amoxicillin is 61.3 minutes.

3-4 hours

One source reports the half life of lansoprazole to be 0.9 - 1.6 hours, while another source cites 0.9 - 2.1 hours. The general consensus is that lansoprazole has a short half life and is approximately 2 hours or less. These numbers may be misleading since it suggests that lansoprazole has a short duration of action when in practice, lansoprazole can effectively inhibit acid secretion for ~24 hours due to it's mechanism of action.

Clearance

The mean clearance of amoxicillin is 21.3L/h.

The reported clearance of lansoprazole is 400-650 mL/min.

Elimination Route

125mg to 1g doses of amoxicillin are 70-78% eliminated in the urine after 6 hours.

After a 250 mg tablet every 12 hours, approximately 20% of the dose is excreted in the urine as clarithromycin, while after a 500 mg tablet every 12 hours, the urinary excretion of clarithromycin is somewhat greater, approximately 30%.

A reported 14-23% of a lansoprazole is eliminated in the urine with this percentage range including both conjugated and unconjugated hydroxylated metabolites.

Pregnancy & Breastfeeding use

There were no adequate and well-controlled studies of in pregnant women. This should be used during pregnancy only if the potential benefit justifies the potential risk of the mother. Amoxicillin is excreted in human milk in very small amounts.

Contraindication

This is contraindicated in patients with known hypersensitivity to any of its component.

Special Warning

Pediatric Use: Because of incompletely developed renal function in neonates and young infants, the elimination of amoxicillin may be delayed. Dosing of amoxicillin should be modified in pediatric patients 12 weeks or younger (≤ 3 months)

Geriatric use: Elderly patients may suffer from asymptomatic renal and hepatic dysfunction. Care should be taken when administering to these patients.

Acute Overdose

If encountered, gastro-intestinal symptoms and disturbance of the fluid and electrolyte balance may be evident. They may be treated symptomatically and supportive with attention to the water/ electrolyte balance. In the absence of an adequate fluid intake and urinary output, crystalluria is a possibility and the antibiotic may be removed from the circulation by haemodialysis. Oral administration can cause gastro intestinal symptoms such as transient diarrhoea, nausea and colic which are dose related and a result of local irritation not toxicity.

Signs & Symptoms : Ingestion of large amounts of Clarithromycin can be expected to produce gastrointestinal symptoms. Symptoms of overdose may largely correspond to the profile of side effects.

Management: There is no specific antidote on overdose. Serum levels of Clarithromycin can not be reduced by haemodialysis or peritoneal dialysis.

Storage Condition

Store in a cool and dry place, protected from light.

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