Amoxicillin Uses, Indication and Side Effect

Amoxicillin is a penicillin antibiotic that fights bacteria. Amoxicillin is used to treat many different types of infection caused by bacteria, such as tonsillitis, bronchitis, pneumonia, and infections of the ear, nose, throat, skin, or urinary tract.These include middle ear infection, strep throat, pneumonia, skin infections, and urinary tract infections among others. It is taken by mouth, or less commonly by injection

Brand Names: Amoxil, Trimox, Moxatag

Drug Fact

Class : β-lactam antibiotic

Category: Prescription Only

Uses: treat many different types of infection caused by bacteria, such as tonsillitis, bronchitis, pneumonia, and infections of the ear, nose, throat, skin, or urinary tract.

Consumed by: adults and children 

Pregnancy category: B

Category B

Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.

Dosage form: tablet, capsule, syrup, dry syrup and injection.

Side Effect :

• Abdominal or stomach cramps or tenderness
• back, leg, or stomach pains
• black, tarry stools
• bleeding gums
• blistering, peeling, or loosening of the skin
• bloating
• blood in the urine
• bloody nose
• chest pain
• chills
• clay-colored stools
• cough

Administration

May be taken with or without food. May be taken w/ meals for better absorption & to reduce GI discomfort.

Reconstitution

Intravenous:

Dissolve 500 mg in 10 mL water for inj to make a final vol of 10.4 mL. Further dilute w/ a suitable IV soln for IV infusion.

Intramuscular:

Add 2.5 mL water for inj and shake vigorously (final vol 2.9 mL).

Incompatibility

Blood products, proteinaceous fluids (e.g. protein hydrolysates), IV lipid emulsions, aminoglycosides.

Contraindications

Hypersensitivity to amoxicillin and other penicillins.

Special Precautions

Patient w/ history of β-lactam allergy, infectious mononucleosis. Renal impairment. Pregnancy and lactation.

Adverse Reactions

Nausea, vomiting, diarrhoea, black hairy tongue, serum sickness-like reactions, erythematous maculopapular rashes, erythema multiforme, Stevens-Johnson syndrome, exfoliative dermatitis, toxic epidermal necrolysis, acute generalised exanthematous pustulosis, hypersensitivity vasculitis, urticaria, increased AST and ALT, cholestatic jaundice, hepatic cholestasis, acute cytolytic hepatitis, crystalluria, anaemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, leucopenia, agranulocytosis. Rarely, reversible hyperactivity, agitation, anxiety, insomnia, confusion, convulsions, behavioural changes, dizziness, tooth discolouration.

Potentially Fatal: Anaphylaxis, Clostridium difficile-associated diarrhoea (CDAD) or pseudomembranous colitis.

Pregnancy Category (US FDA)

PO: B

Patient Counseling Information

Maintain adequate fluid intake and urinary output.

MonitoringParameters

Monitor renal, hepatic, and haematologic functions; signs of anaphylaxis during 1st dose.

Overdosage

Symptoms: GI effects (e.g. nausea, vomiting and diarrhoea). Management: Symptomatic treatment w/ attention to water/electrolyte balance.

Drug Interactions

May reduce the efficacy of OC. May increase the effect of anticoagulants. Increased risk of allergic reactions w/ allopurinol. Increased and prolonged blood levels w/ probenecid. Chloramphenicol, macrolides, sulfonamides and tetracyclines may interfere w/ the bactericidal effect of amoxicillin.

Lab Interference

False-positive reactions when testing for the presence of glucose in urine using CLINITEST, Benedict's soln, or Fehling's soln.

Action

Description: Amoxicillin inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell wall by binding to 1 or more of the penicillin-binding proteins (PBPs), thus inhibiting cell wall biosynthesis resulting in bacterial lysis.

Pharmacokinetics:

Absorption: Rapidly and completely absorbed from the GI tract. Time to peak plasma concentration: 1-2 hr.

Distribution: Widely distributed into body tissues and fluids. Crosses the placenta and enters breast milk (small amounts). Plasma protein binding: Approx 20%.

Metabolism: Undergoes partial hepatic metabolism and converted to penicilloic acid.

Excretion: Via urine (60% as unchanged drug) and faeces. Plasma half-life: 1-1.5 hr.

Chemical Structure

Storage

Store between 20-25°C. Reconstituted oral susp: Store between 2-8°C.