Amoxicillin Information
Amoxicillin ()
Amoxicillin () Description
Formulations of Amoxicillin () powder for oral suspension contain Amoxicillin () , a semisynthetic antibiotic, an analog of ampicillin, with a broad spectrum of bactericidal activity against many gram-positive and gram-negative microorganisms. Chemically, it is (2,5,6)-6-[()-(-)-2-amino-2-(-hydroxyphenyl)acetamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid trihydrate. It may be represented structurally as:
The Amoxicillin () molecular formula is CHNOS•3HO, and the molecular weight is 419.45.
Powder for oral suspension of Amoxicillin () is intended for oral administration.
Amoxicillin () Clinical Pharmacology
Amoxicillin () is stable in the presence of gastric acid and is rapidly absorbed after oral administration. The effect of food on the absorption of Amoxicillin () from the tablets and suspension of Amoxicillin () has been partially investigated. The 400 mg and 875 mg formulations have been studied only when administered at the start of a light meal. However, food effect studies have not been performed with the 200 mg and 500 mg formulations. Amoxicillin () diffuses readily into most body tissues and fluids, with the exception of brain and spinal fluid, except when meninges are inflamed. The half-life of Amoxicillin () is 61.3 minutes. Most of the Amoxicillin () is excreted unchanged in the urine; its excretion can be delayed by concurrent administration of probenecid. In blood serum, Amoxicillin () is approximately 20% protein-bound.
Orally administered doses of 250 mg and 500 mg Amoxicillin () capsules result in average peak blood levels 1 to 2 hours after administration in the range of 3.5 mcg/mL to 5 mcg/mL and 5.5 mcg/mL to 7.5 mcg/mL, respectively.
Mean Amoxicillin () pharmacokinetic parameters from an open, two-part, single-dose crossover bioequivalence study in 27 adults comparing 875 mg of Amoxicillin () with 875 mg of Amoxicillin () /clavulanate potassium showed that the 875 mg tablet of Amoxicillin () produces an AUC of 35.4 ± 8.1 mcg•hr/mL and a C of 13.8 ± 4.1 mcg/mL. Dosing was at the start of a light meal following an overnight fast.
Orally administered doses of Amoxicillin () suspension, 125 mg/5 mL and 250 mg/5 mL, result in average peak blood levels 1 to 2 hours after administration in the range of 1.5 mcg/mL to 3.0 mcg/mL and 3.5 mcg/mL to 5 mcg/mL, respectively.
Oral administration of single doses of 400 mg/5 mL suspension of Amoxicillin () to 24 adult volunteers yielded the following comparable pharmacokinetic data:
Detectable serum levels are observed up to 8 hours after an orally administered dose of Amoxicillin () . Following a 1 gram dose and utilizing a special skin window technique to determine levels of the antibiotic, it was noted that therapeutic levels were found in the interstitial fluid. Approximately 60% of an orally administered dose of Amoxicillin () is excreted in the urine within 6 to 8 hours.
Amoxicillin () Indications And Usage
Amoxicillin () is indicated in the treatment of infections due to susceptible (ONLY β-lactamase–negative) strains of the designated microorganisms in the conditions listed below:
Amoxicillin () Contraindications
A history of allergic reactions to any of the penicillins is a contraindication.
Amoxicillin () Warnings
SERIOUS AND OCCASIONALLY FATAL HYPERSENSITIVITY (ANAPHYLACTIC) REACTIONS HAVE BEEN REPORTED IN PATIENTS ON PENICILLIN THERAPY. ALTHOUGH ANAPHYLAXIS IS MORE FREQUENT FOLLOWING PARENTERAL THERAPY, IT HAS OCCURRED IN PATIENTS ON ORAL PENICILLINS. THESE REACTIONS ARE MORE LIKELY TO OCCUR IN INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY AND/OR A HISTORY OF SENSITIVITY TO MULTIPLE ALLERGENS. THERE HAVE BEEN REPORTS OF INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY WHO HAVE EXPERIENCED SEVERE REACTIONS WHEN TREATED WITH CEPHALOSPORINS. BEFORE INITIATING THERAPY WITH Amoxicillin () , CAREFUL INQUIRY SHOULD BE MADE CONCERNING PREVIOUS HYPERSENSITIVITY REACTIONS TO PENICILLINS, CEPHALOSPORINS, OR OTHER ALLERGENS. IF AN ALLERGIC REACTION OCCURS, Amoxicillin () SHOULD BE DISCONTINUED AND APPROPRIATE THERAPY INSTITUTED.
If CDAD is suspected or confirmed, ongoing antibiotic use not directed against may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of , and surgical evaluation should be instituted as clinically indicated.
Amoxicillin () Precautions
The possibility of superinfections with mycotic or bacterial pathogens should be kept in mind during therapy. If superinfections occur, Amoxicillin () should be discontinued and appropriate therapy instituted.
A high percentage of patients with mononucleosis who receive ampicillin develop an erythematous skin rash. Thus, ampicillin-class antibiotics should not be administered to patients with mononucleosis.
Prescribing Amoxicillin () in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
As with any potent drug, periodic assessment of renal, hepatic, and hematopoietic function should be made during prolonged therapy.
All patients with gonorrhea should have a serologic test for syphilis at the time of diagnosis. Patients treated with Amoxicillin () should have a follow-up serologic test for syphilis after 3 months.
Probenecid decreases the renal tubular secretion of Amoxicillin () . Concurrent use of Amoxicillin () and probenecid may result in increased and prolonged blood levels of Amoxicillin () . Chloramphenicol, macrolides, sulfonamides, and tetracyclines may interfere with the bactericidal effects of penicillin. This has been demonstrated ; however, the clinical significance of this interaction is not well documented.
In common with other antibiotics, Amoxicillin () may affect the gut flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral estrogen/progesterone contraceptives.
High urine concentrations of ampicillin may result in false-positive reactions when testing for the presence of glucose in urine using CLINITEST, Benedict’s Solution, or Fehling’s Solution. Since this effect may also occur with Amoxicillin () , it is recommended that glucose tests based on enzymatic glucose oxidase reactions (such as CLINISTIX) be used.
Following administration of ampicillin to pregnant women, a transient decrease in plasma concentration of total conjugated estriol, estriol-glucuronide, conjugated estrone, and estradiol has been noted. This effect may also occur with Amoxicillin () .
An analysis of clinical studies of Amoxicillin () was conducted to determine whether subjects aged 65 and over respond differently from younger subjects. Of the 1,811 subjects treated with capsules of Amoxicillin () , 85% were
This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.
Amoxicillin () may be taken every 8 hours or every 12 hours, depending on the strength of the product prescribed.
Patients should be counseled that antibacterial drugs, including Amoxicillin () , should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Amoxicillin () is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may: (1) decrease the effectiveness of the immediate treatment, and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Amoxicillin () or other antibacterial drugs in the future.
Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as 2 or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.
Amoxicillin () Adverse Reactions
As with other penicillins, it may be expected that untoward reactions will be essentially limited to sensitivity phenomena. They are more likely to occur in individuals who have previously demonstrated hypersensitivity to penicillins and in those with a history of allergy, asthma, hay fever, or urticaria. The following adverse reactions have been reported as associated with the use of penicillins:
Nausea, vomiting, diarrhea, black hairy tongue, and hemorrhagic/pseudomembranous colitis.
Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment. (See .)
Anaphylaxis (See ).
Serum sickness–like reactions, erythematous maculopapular rashes, erythema multiforme, Stevens-Johnson syndrome, exfoliative dermatitis, toxic epidermal necrolysis, acute generalized exanthematous pustulosis, hypersensitivity vasculitis and urticaria have been reported.
NOTE:
Amoxicillin () Overdosage
In case of overdosage, discontinue medication, treat symptomatically, and institute supportive measures as required. If the overdosage is very recent and there is no contraindication, an attempt at emesis or other means of removal of drug from the stomach may be performed. A prospective study of 51 pediatric patients at a poison-control center suggested that overdosages of less than 250 mg/kg of Amoxicillin () are not associated with significant clinical symptoms and do not require gastric emptying.
Interstitial nephritis resulting in oliguric renal failure has been reported in a small number of patients after overdosage with Amoxicillin () .
Crystalluria, in some cases leading to renal failure, has also been reported after Amoxicillin () overdosage in adult and pediatric patients. In case of overdosage, adequate fluid intake and diuresis should be maintained to reduce the risk of Amoxicillin () crystalluria.
Renal impairment appears to be reversible with cessation of drug administration. High blood levels may occur more readily in patients with impaired renal function because of decreased renal clearance of Amoxicillin () . Amoxicillin () may be removed from circulation by hemodialysis.
Amoxicillin () Dosage And Administration
Amoxicillin () oral suspensions may be given without regard to meals. The 400 mg suspension has been studied only when administered at the start of a light meal. However, food effect studies have not been performed with the 200 mg formulation.
Due to incompletely developed renal function affecting elimination of Amoxicillin () in this age group, the recommended upper dose of Amoxicillin () is 30 mg/kg/day divided q12h.
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After reconstitution, the required amount of suspension should be placed directly on the child’s tongue for swallowing. Alternate means of administration are to add the required amount of suspension to formula, milk, fruit juice, water, ginger ale, or cold drinks. These preparations should then be taken immediately. To be certain the child is receiving full dosage, such preparations should be consumed in entirety.
All patients with gonorrhea should be evaluated for syphilis. (See .)
Larger doses may be required for stubborn or severe infections.
Patients with impaired renal function do not generally require a reduction in dose unless the impairment is severe. Severely impaired patients with a glomerular filtration rate of
Hemodialysis patients should receive 500 mg or 250 mg every 24 hours, depending on severity of the infection. They should receive an additional dose both during and at the end of dialysis.
There are currently no dosing recommendations for pediatric patients with impaired renal function.
Prepare suspension at time of dispensing as follows: Tap bottle until all powder flows freely. Add approximately 1/3 of the total amount of water for reconstitution (see table below) and shake vigorously to wet powder. Add remainder of the water and again shake vigorously.
Each teaspoonful (5 mL) will contain 125 mg Amoxicillin () .
Each teaspoonful (5 mL) will contain 200 mg Amoxicillin () .
Each teaspoonful (5 mL) will contain 250 mg Amoxicillin () .
Each teaspoonful (5 mL) will contain 400 mg Amoxicillin () .
NOTE:
Amoxicillin () How Supplied
Each 5 mL of reconstituted fruity-flavored suspension contains 125, 200, 250, or 400 mg Amoxicillin () as the trihydrate.
125 mg/5 mL
200 mg/5 mL
250 mg/5 mL
400 mg/5 mL
Store at 20°-25°C (68°-77°F) [See USP Controlled Room Temperature].
Dispense in a tight container.
Amoxicillin () References
CLINITEST is a registered trademark of Miles, Inc.
CLINISTIX is a registered trademark of Bayer Corporation.
CLOtest is a registered trademark of Kimberly-Clark Corporation.
Distributed by: Eatontown, NJ 07724
Manufactured by: P.O. Box 182400Amman 1111 - Jordan
Outsert Rev. 11/2009Label Rev. 05/2010
Amoxicillin () Principal Display Panel
Amoxicillin () Powder for Oral Suspension125 mg/5mL, 80 mLNDC 0143-9888-80
Amoxicillin () Principal Display Panel
Amoxicillin () Powder for Oral Suspension200 mg/5 mL, 75 mLNDC 0143-9886-75
Amoxicillin () Principal Display Panel
Amoxicillin () Powder for Oral Suspension250 mg/5 mL, 80 mLNDC 0143-9889-80
Amoxicillin () Principal Display Panel
Amoxicillin () Powder for Oral Suspension400 mg/5mL, 75 mLNDC 0143-9887-75
