HIMOX Amoxicillin Trihydrate 250mg / 5mL Powder for Suspension 60mL
Indications/Uses
As prophylaxis for endocarditis: For the prevention of bacteremia, associated with procedures such as dental extraction in patients at risk of developing bacterial endocarditis.
Step down treatment for severe infections due to susceptible organisms, initially given intravenous antimicrobial therapy.
Dosage/Direction for Use
Usual Adult Dose: 250 mg to 500 mg every 8 hours or 500 mg every 12 hours, depending on the type and severity of infection.
Maximum Dose: 6 g/day in divided doses. An adult dose of 3 g twice daily is recommended in appropriate cases for the treatment of severe or recurrent purulent respiratory tract infection.
Recommended Adult Dose for Specific Infections: See Table 3.
Usual Pediatric Dose: Neonates and infants ≤3 months: 20 to 30 mg/kg body weight/day in divided doses every 12 hours.
Infants >3 months and Children <40 kg: 25 to 50 mg/kg body weight/day in divided doses every 8 hours or every 12 hours.
Recommended Pediatric Dose for Specific Infections: See Table 4.
Patients with Renal Impairment: See Table 5.
Usual Duration of Treatment: For most infections: 5 to 14 days, depending on the type and severity of infection. Continue treatment for at least 48 to 72 hrs after the patient becomes asymptomatic or after evidence of bacterial eradication has been continued.
For β-hemolytic streptococcal infections: At least 10 days to prevent rheumatic fever or glomerulonephritis.
For Lyme Disease: At least 12 days.
Frequent bacteriologic and clinical appraisal is necessary during treatment of chronic urinary tract infections and maybe required for several months after therapy has been completed.
Or, as prescribed by a physician.
Directions for Reconstitution: see Table 6.
Overdosage
Crystalluria, in some cases leading to renal failure, has been observed after amoxicillin overdosage in adults and children. Adequate fluid intake and diuresis should be maintained to reduce the risk of amoxicillin crystalluria.
Interstitial nephritis resulting in oliguric renal failure has also been reported in a small number of patients after overdose with amoxicillin.
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.
Administration
Contraindications
Patient with infectious mononucleosis since amoxicillin is likely to cause a maculopapular rash.
Special Precautions
Serious anaphylactoid reactions require immediate emergency treatment with epinephrine. Oxygen, intravenous steroids, and airway management, including intubation, should also be administered as indicated.
Clostridium difficile-associated diarrhea (CDAD) and colitis have been reported with the use of nearly all antibacterial agents, including amoxicillin, and may range in severity from mild to life threatening. It is important to consider this diagnosis in patients who present with diarrhea following administration of antibacterial agents.
During administration of high doses of amoxicillin, it is recommended to maintain adequate fluid intake and urinary output in order to reduce the possibility of crystalluria associated with amoxicillin therapy.
In patients with renal impairment, the dose of amoxicillin should be adjusted based on the degree of impairment.
As with any potent drug, periodic assessment of organ system functions, including renal, hepatic, hematopoietic, is recommended during prolonged therapy.
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 other antibacterial drugs, long term or repeated use may result in overgrowth of nonsusceptible organisms, including fungi.
Renal Impairment: The doses and/or frequency of amoxicillin administration should be modified in response to the degree of renal impairment, severity of infection, and susceptibility of the causative organisms (see Dosage & Administration).
Use in Children: Neonates and young infants have incompletely developed renal function which may result in delayed elimination of amoxicillin. Dosing of amoxicillin should be modified in pediatric patients 12 weeks old or younger (≤3 months old) (see Dosage & Administration).
Use in the Elderly: Since elderly patients are more likely to have decreased renal function, care should be taken in dose selection.
Use In Pregnancy & Lactation
Lactation: Since amoxicillin is distributed into human milk and may lead to sensitization of the infant, the drug should be used with caution when breastfeeding.
Adverse Reactions
The following adverse reactions have been reported with the use of amoxicillin: Dermatologic/Hypersensitivity Reactions: Anaphylaxis (usually associated with the parenteral dosage form), serum sickness-like reactions (urticaria or skin rash accompanied by arthritis, arthralgia, myalgia, and frequently fever); severe allergic reactions including angioedema; exanthema, acute and generalized exanthematous pustulosis (AGEP), bullous and exfoliative dermatitis, erythematous maculopapular rashes, erythema multiforme, hypersensitivity vasculitis, mucocutaneous/oral and vaginal candidiasis, pruritus, Stevens-Johnson syndrome, toxic epidermal necrolysis.
GI: Nausea, vomiting, diarrhea, black "hairy" tongue, CDAD and colitis (during or following discontinuance of amoxicillin); hemorrhagic colitis; acute, transient enterocolitis with severe abdominal pain and bloody diarrhea, but without evidence of CDAD and colitis; glossitis, stomatitis, epigastric distress, gastritis, flatulence, soft stools, loss of appetite/anorexia, enanthemas/sore mouth or tongue, dry mouth, taste disturbances.
Nervous System: Agitation, anxiety, behavioral changes, confusion, convulsions (at extremely high doses), dizziness, reversible hyperactivity, hyperkinesia, insomnia.
When penicillin reaches a high concentration in the CSF, neurotoxic symptoms consisting of myoclonia, convulsive seizures and depressed consciousness may occur. Unless drug administration is discontinued or its dosage reduced, the syndrome may progress to coma and death.
Hemic and Lymphatic System: Anemia, including hemolytic anemia; agranulocytosis, abnormal platelet aggregation, eosinophilia, leukopenia, neutropenia, prolongation of bleeding time, prothrombin time and activated partial thromboplastin time (APTT); thrombocytopenia, thrombocytopenic purpura.
Hepatic: A moderate rise in aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT); transient increases in serum alkaline phosphatase and lactate dehydrogenase levels; hepatic dysfunction including cholestatic jaundice, hepatic cholestasis and acute cytolytic hepatitis.
Renal: Acute interstitial nephritis, crystalluria.
Other Adverse Effects: Tooth discoloration (brown, yellow, or gray staining) mostly in pediatric patients. In most cases, discoloration was reduced or eliminated with brushing or dental cleaning.
Drug Interactions
Anticoagulants: Prolongation of prothrombin time has been reported rarely in patients receiving amoxicillin. Appropriate monitoring should be undertaken when anticoagulants are prescribed concomitantly.
Bacteriostatic agents (e.g., Chloramphenicol, macrolides, sulfonamides, and tetracyclines): These antibacterial agents may interfere with the bactericidal effects of penicillin. This has been demonstrated in vitro; however, the clinical significance of this interaction is not well documented.
Beta-lactamase Inhibitors: In vitro and in vivo studies indicate that the combination of amoxicillin with clavulanic acid or sulbactam results in a synergistic bactericidal effect against many strains of β-lactamase-producing bacteria.
Digoxin: Concurrent administration with amoxicillin may result in increased absorption of digoxin.
Methotrexate: Concomitant use of penicillins (e.g., amoxicillin) may decrease the renal clearance of methotrexate, presumably by inhibiting renal tubular secretion of the drug. Increased serum concentrations of methotrexate, resulting in GI or hematologic toxicity, have been reported. Careful monitoring is recommended during concomitant therapy.
Oral Contraceptives: As with other antibiotics, amoxicillin may affect the gut flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral estrogen/progesterone contraceptives.
Probenecid: Concurrent use of amoxicillin and probenecid may result in increased and prolonged blood levels of amoxicillin.
Interference with Laboratory Tests: 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. Since the effect may also occur with amoxicillin, it is recommended that glucose tests based on enzymatic glucose oxidase reactions (e.g., Clinistix) be used.
Administration of ampicillin to pregnant women may result in a transient decrease in plasma concentrations of total conjugated estriol, estriol-glucuronide, conjugated estrone, and estradiol. This effect may also occur with amoxicillin.
Amoxicillin may interfere with protein testing when colorimetric methods are used.
Storage
Action
Pharmacokinetics: After oral administration, amoxicillin is stable in gastric acid and about 74-92% of a single oral dose of the drug is absorbed from the gastrointestinal (GI) tract of fasting adults. Peak serum concentrations (Cmax) of amoxicillin are generally attained within 1-2 hours and serum concentrations are usually low and undetectable 6-8 hours later. Increasing the dose results in a corresponding increase in Cmax and area under the serum concentration-time curves (AUC).
After oral administration of a single dose of amoxicillin 250 or 500 mg, the Cmax were 3.5-5 or 5.5-11 mcg/mL, respectively. In a study in healthy, fasting adults who received a single oral dose of amoxicillin 500 mg, the mean serum drug concentrations were 3.3, 6.7, 9.3, 5.8, and 0.6 mcg/mL at 30 minutes, 1 hour, 2 hours, 3 hours, and 4 hours, respectively, after the dose.
In children 4 to 45 months old given amoxicillin oral suspension 15 mg/kg daily, the serum drug concentrations ranged from 2.4-8.5, 1.9-11.3, 1.7-6.4, 0.17-1.9, and 0.14-3.3 mcg/mL at 30 minutes, 1 hour, 2 hours, 4 hours, and 6 hours, respectively, after a dose.
Oral absorption of amoxicillin is delayed in neonates compared with absorption in children and adults. After oral administration of a single dose of amoxicillin in neonates, the Cmax is generally attained within 3-4.5 hours compared with 1-2 hours in children and adults.
The apparent volume of distribution of amoxicillin ranges from 0.267 to 0.315 L/kg in adults with normal renal function. Amoxicillin is generally distributed into ascitic, synovial, and pleural fluids, middle ear effusions, bronchial and maxillary sinus secretions, sputum, and tonsils. It is also distributed into the liver, lungs, gallbladder, prostate, and muscle. Low concentrations of the drug are also attained in saliva, sweat and tears. Amoxicillin is distributed into bile in varying amounts. If biliary obstruction is not present, amoxicillin concentration in bile is generally 1-30 times greater than concurrent serum concentrations of the drug. As with other penicillins, only negligible amounts of amoxicillin have been detected in aqueous humor. Minimal drug concentrations are attained in cerebrospinal fluid (CSF) of patients with uninflamed meninges; higher concentrations may be attained when meninges are inflamed.
Amoxicillin readily crosses the placenta and is distributed into human milk in low concentrations. Amoxicillin concentrations in cord blood are reportedly 25-33% of concurrent maternal serum concentrations. About 17-20% of the drug is bound to serum proteins.
As with other penicillins, amoxicillin is excreted by renal tubular secretion and to a lesser extent by glomerular filtration. Small amounts of the drug are also excreted in feces and bile. About 19-33% of the drug is excreted in urine as penicilloic acid, which is a microbiologically inactive metabolite.
Serum concentration of amoxicillin is generally higher and serum half-life (t1/2) is longer in neonates than in older children or adults. In general, the serum t1/2 of the drug is inversely proportional to birthweight, gestational age and chronologic age. This appears to result from immature mechanisms for renal tubular secretion of the drug. The serum t1/2 of amoxicillin is about 3.7 hours in full-term neonates, and 0.9-1.9 hours in infants and children.
Amoxicillin is removed by hemodialysis. Only minimal amounts appear to be removed by peritoneal dialysis.
Microbiology: Antimicrobial Spectrum of Activity: Amoxicillin is a broad spectrum aminopenicillin antibiotic that is structurally related to ampicillin. It is rapidly bactericidal against susceptible organisms during the stage of active multiplication. Amoxicillin is ineffective in most staphylococcal infections since it is destroyed by β-lactamase.
Amoxicillin is active in vitro and in clinical infections against most strains of the following microorganisms: See Table 1.
The following microorganisms are generally sensitive to amoxicillin in vitro: See Table 2.
MedsGo Class
Features
- Amoxicillin