Northeastern U.S. Children Show Signs of Worse Asthma in Wildfire Smoke
December 12, 2025
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Brand Name :
Ampicillin
(United Kingdom) [Available]Synonyms :
ampicillin
Class :
Penicillin
Brand Name :
Ampicillin
(United Kingdom) [Available]Synonyms :
ampicillin
Class :
Penicillin
Dosage forms with strengths:
Capsules: 250mg, 500mg (Oral absorption is 39% to 54%)
Oral Suspensions: 125mg/5ml, 250mg/ml
Powder for injection: 125mg, 250mg, 500mg, 1g, 2g, 10g, 1.5g, 3g, 15g
Orally ampicillin can be taken without food with a minimum of 8 ounces of water.
Genitourinary tract infection:
Gonorrhea:
Respiratory tract:
Gastrointestinal tract infections:
Ear, nose, and throat infections:
Endocarditis: IV dose recommendation
Kidney dysfunction
Bite wound infection (animal or human bite)
Meningitis/Treatment for bacterial infection (Haemophilus influenzae, L. monocytogenes, Neisseria meningitidis, Streptococcus agalactiae, Streptococcus pneumoniae, Enterococcus spp.):
Genitourinary Tract Infections
500mg orally every 12hrs
250mg orally every 8hrs
3.5g of the single oral dose administered simultaneously, with 1g probenecid
Indicated for Respiratory tract:
875mg oral dose every 12hrs
500mg oral dose every 8hrs
Indicated for gastrointestinal infections:
500mg orally every 12hrs
250mg orally every 8hrs
Ear, Nose And Throat Infections
500mg orally every 12hrs for 7 to 14 days
250mg orally every 8hrs for 7 to 14 days
2g every 4hrs in combination with gentamycin for 4 weeks
2g every 4hrs in combination with ceftriaxone for 6 weeks
Indicated for kidney dysfunction:
IV: 1 to 2g every 6 hrs or 2g every 4hrs (expert opinion)
Bite wound infection (animal or human bite)
500mg orally every 12hrs
250mg orally every 8hrs
Ampicillin/sulbactam (ratio of 2:1) IM, IV: 1.5g to 3g every 6hrs for 5 to 14days
Meningitis/Treatment for bacterial infection (Haemophilus influenzae, L. monocytogenes, Neisseria meningitidis, Streptococcus agalactiae, Streptococcus pneumoniae, Enterococcus spp.):
500mg orally four times a day
IV: 2g every 4 hrs for 7 to 21 days
Senior dosage (above 65 years and older):
Start on a dose of 250mg divided six times a day or start on a different schedule, especially for the patients with renal impairment
Senior dosage (above 65 years and older):
Start on a dose of 250mg divided six times a day or start on a different schedule, especially for the patients with renal impairment
Dosage forms with strengths:
Capsules: 250mg, 500mg (Oral absorption is 39% to 54%)
Oral Suspensions: 125mg/5ml, 250mg/ml
Powder for injection: 125mg, 250mg, 500mg, 1g, 2g, 10g, 1.5g, 3g, 15g
Orally ampicillin can be taken without food with a minimum of 8 ounces of water.
Genitourinary tract infection:
Ear, nose, and throat infections:
Respiratory tract:
Gastrointestinal tract infections:
Pneumonia and other bacterial infections (off-label)
Surgical prophylaxis IV:
Note: For oral therapy usually, amoxicillin is preferred over ampicillin due to better absorption. In some cases, IV ampicillin may be administered as a 24 hrs continuous infusion for ease of patient.
Genitourinary Tract Infections
(>20kg weight):100mg/kg/day total in equally divided and spaced doses
(<20kg weight): less than 30mg/kg per day in four equally divided and spaced doses
Ear, Nose And Throat Infections
(<20kg weight): 30-40mg/kg every 12hr for 10days
(>20kg weight): 500mg every 12hr or 250mg every 8hr for 10 to 15 days
Indicated for Gastrointestinal tract infections:
(0-17year old, weight>20kg): 500mg four times a day
(0-17 years, weight <20kg): 100mg/kg per day in four equally divided and spaced doses
90mg/kg/day every 12hr for 10days (do not exceed 4000mg/day)
Group A Streptococcus: 50-75 mg/kg/day every 12hr for 10 days; (do not exceed 4000mg/day)
H. influenza: 75-100 mg/kg/day every 8hr for 10 days; (do not exceed 4000mg/day)
Surgical prophylaxis IV:
50mg/kg before surgical incision within 60 mins; can be repeated in 2 hrs for excessive blood loss or lengthy procedure
Dosage forms with strengths:
Capsules: 250mg, 500mg (Oral absorption is 39% to 54%)
Oral Suspensions: 125mg/5ml, 250mg/ml
Powder for injection: 125mg, 250mg, 500mg, 1g, 2g, 10g, 1.5g, 3g, 15g
Orally ampicillin can be taken without food with a minimum of 8 ounces of water.
Dosage for Respiratory tract and gastrointestinal tract infections:
Start on a dose of 250mg divided six times a day or start on a different schedule, especially for the patients with renal impairment.
Chloroquine reduces the serum concentrations of ampicillin. Apply at least 2 hours of gap between administration of chloroquine and ampicillin.
Interaction with allopurinol may enhance the allergic reaction to ampicillin.
may diminish the serum concentration when combined with ampicillin
Typhoid vaccine (Ty21a) should be avoided in patients on treatment of systemic antibacterial agents. Penicillin antibiotics reduce the therapeutic effect of live attenuated vaccine TY21a.
When both drugs are combined, there may be a reduced therapeutic effect of ampicillin sodium sulfate/potassium sulfate/magnesium
When both drugs are combined, there may be an increased risk or severity of adverse effects
when both drugs are combined, there may be a reduced effect of ampicillin
when both drugs are combined, there may be a decreased effects of ampicillin
tetracycline may decrease the therapeutic effects of penicillins by interfering with its bactericidal effects
tetracycline may decrease the therapeutic effects of penicillins by interfering with its bactericidal effects
Therapy monitoring suggested. May increase serum concentrations when interacting with penicillins.
Ampicillin may increase the serum concentrations of methotrexate.
Decreases the ampicillin serum concentrations.
antipyrine has the potential to reduce the rate of excretion of ampicillin, potentially leading to an elevation in the serum concentration
ampicillin has the potential to reduce the rate of excretion of idebenone, leading to an elevation in levels of serum
When ampicillin is used together with capsaicin, this leads to enhanced risk or seriousness of methemoglobinemia
the excretion rate of ampicillin, when decreased by pralidoxime, results in increased serum level
fentiazac may reduce the elimination rate of ampicillin, resulting in a greater serum level
ampicillin leads to a reduction in the rate of excretion of eucalyptus oil which leads to increased level of serum
cefpirome leads to a reduction in the rate of excretion of ampicillin which leads to increased level of serum
ampicillin leads to a reduction in the rate of excretion of chromous sulfate, which leads to an increased level of serum
ampicillin leads to a reduction in the rate of excretion of pentaerythritol tetranitrate, which leads to an increased level of serum
ampicillin leads to a reduction in the rate of excretion of potassium acetate, which leads to an increased level of serum
ampicillin leads to a reduction in the rate of excretion of potassium perchlorate, which leads to an increased level of serum
ampicillin leads to a reduction in the rate of excretion of nitric oxide, which leads to an increased level of serum
ampicillin: it may increase the risk or severity of CNS depression
ampicillin: it may increase the risk or severity of CNS depression
ampicillin: it may increase the risk or severity of CNS depression
ampicillin: it may increase the risk or severity of CNS depression
ampicillin: it may increase the risk or severity of CNS depression
ampicillin may decrease the excretion rate of almasilate, leading to higher serum levels
ampicillin may increase levels of willow bark or vice versa by decreasing renal clearance
ampicillin: it may increase the serum concentration of rosoxacin
may increase serum concentration of methotrexate
may increase the serum concentration of trimetrexate
anticoagulant properties or actions of fluindione are increased with ampicillin
the rate of excretion of aurothioglucose may be reduced with ampicillin
ampicillin might lead to a reduction in the rate of excretion of telavancin, potentially leading to elevated levels of serum
Probenecid may enhance serum concentrations of ampicillin.
Ampicillin may reduce the serum concentrations of active metabolites of mycophenolate.
Actions and Spectrum:
Actions:
Ampicillin stops bacterial cell walls from forming properly. It disrupts the linking of peptidoglycan layers by interfering with key enzymes. This weakness damages the cell wall structure. Not only does this compromise the bacterial cell wall’s integrity, it also kills bacteria. By weakening cell walls, ampicillin makes bacteria vulnerable to osmotic pressure changes. This causes cells to rupture, leading to bacterial death. Ampicillin’s dual action – halting growth and eliminating susceptible strains – shows its effectiveness.
Spectrum:
Ampicillin helps treat bacterial infections. It works on meningitis, which affects the membranes around the brain and spine. It also fights infections in the throat, urinary tract, lungs, sinuses, reproductive organs, and digestive system. Ampicillin belongs to penicillin drugs. These drugs remove bacteria from the body. However, ampicillin can’t treat viral infections like colds and flu. Using antibiotics unnecessarily allows antibiotic-resistant infections to develop later.
Note: Appearance of rash is higher in patients with a viral infection, Salmonella infection, lymphocytic leukemia, or patients that have hyperuricemia.
Patients with a history of sensitivity to multiple allergens or hypersensitivity to beta-lactams may develop severe anaphylactoid reactions with ampicillin therapy. If these effects don’t go away within one week, talk to your doctor or pharmacist.
Black Box Warning:
Ampicillin gets used in this medication. If you have allergies to ampicillin or other parts in Ampi, Penglobe, Omnipen, or Principen, don’t use them. Kids should also avoid these drugs.
Contraindication/Caution:
Contraindications
Cautions
Pharmacology:
Ampicillin fights bacteria. It’s from the penicillin group of antibiotics. It works on many bacteria types. Doctors often prescribe it with other drugs. This combo enhances ampicillin’s ability to beat bacterial infections.
Pharmacodynamics:
Ampicillin combats bacteria by disrupting their cell walls. It blocks enzymes that build cell walls, weakening them. This makes bacterial cells burst in changing pressures, killing them. But, the time ampicillin takes to destroy bacteria matters. It needs enough exposure to eliminate bacterial populations.
Pharmacokinetics:
Absorption
The medicine begins working around 1-2 hours after taking it. However, the body only absorbs 30-55% of the drug.
Distribution
A small portion, 15-25%, binds to proteins.
Metabolism
Before elimination, part of the medicine breaks down.
Elimination and Excretion
The body gets rid of it within 0.7-1.5 hours. 20-64% leaves through the digestive system. 60-70% passes out unchanged in the urine.
Administration:
Ampicillin gets given through different ways. For milder infections, you may take it by mouth as a pill or liquid. For severe cases, it is injected straight into your vein (IV) or muscle (IM). The type of infection determines how it’s given.
Patient Information Leaflet:
Ampicillin fights bacteria. It doesn’t cure viral illnesses like flu or colds. Take it by mouth four times daily, about every six hours. You can take it before eating or two hours after food, with water. Follow your doctor’s dosage instructions. Don’t stop taking it early or extend use without your doctor’s approval. It may cause side effects like sore tongue, mouth ulcers, vomiting, nausea, and diarrhea. Seek immediate medical care if you experience severe abdominal pain, easy bruising, or yellowed eyes. Older adults might have trouble eliminating ampicillin due to kidney issues. Keep it at room temperature away from sunlight and moisture. Store where children and pets cannot access.
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