Ampicillin

Ampicillin is an antibiotic from the penicillin group that is used to treat a wide range of bacterial infections. This antibiotic is a beta-lactam antibiotic and works by killing bacteria by interfering with their ability to build a cell wall, which is necessary for them to survive and reproduce.

Ampicillin disrupts the process of bacterial cell wall synthesis at the last stage of bacterial cell division by binding and activating specific proteins (penicillin-binding proteins) that play a key role in the construction of bacterial cell walls. This leads to weakening and subsequent destruction of the wall, resulting in bacterial death.

Indications Ampicillin

1. Respiratory tract infections:

   • Bronchitis
   • Pneumonia
   • Angina

2. Urinary tract infections:

   • Cystitis
   • Pyelonephritis
   • Prostatitis

3. GI (gastrointestinal) infections:

   • Salmonellosis
   • Shigellosis (dysentery).

4. Gynecologic infections:

   • Endometritis
   • Gonorrhea (often in combination with other antibiotics)

5. Skin and soft tissue infections:

   • Abscesses
   • Boils
   • Infected dermatoses

6. Meningitis:

   • Treatment of meningitis caused by meningococci and other susceptible organisms

7. Sepsis:

   • Bacterial sepsis caused by sensitive bacteria

8. Infection Prevention:

   • Prevention of infectious complications in surgery, especially in abdominal surgery and gynecology

Release form

1. Oral tablets

Ampicillin tablets are usually intended to be taken orally and are available in different dosages, such as 250 mg and 500 mg. This form is convenient for treatment at home.

2. Capsules

Like tablets, ampicillin capsules are intended for oral use and are often available in 250 mg and 500 mg dosages. The capsules are easy to swallow and convenient to use.

3. Powder for preparation of oral suspension

This form of ampicillin is used to create a suspension just before use, providing a convenient way to take the medicine for children and adults who have difficulty swallowing tablets or capsules. The suspension usually has a dosage expressed as mg per ml.

4. Powder for injection

Ampicillin is also available as a powder that is diluted for intravenous or intramuscular administration. This form is used in hospital settings to treat serious infections that require immediate action of the antibiotic. Dosages may vary depending on the severity of the condition and the specifics of the infection.

The choice of ampicillin dosage form depends on many factors, including the patient's age, the type and severity of the infection, and the patient's ability to take the drug orally.

Pharmacodynamics

1. Mechanism of Action: Ampicillin inhibits the synthesis of the bacterial cell wall, leading to the death of bacteria. It binds to proteins called transpeptidases, which are involved in the formation of peptidoglycan, the main component of the bacterial cell wall. This leads to disruption of peptidoglycan synthesis and weakening of the cell wall, which ultimately leads to the death of the bacterial cell.

2. Spectrum of action: Ampicillin is generally active against Gram-positive bacteria such as

Gram-positive bacteria:

• Streptococcus pneumoniae
• Streptococcus pyogenes (beta-hemolytic group A streptococcus)
• Streptococcus agalactiae (beta-hemolytic group B streptococcus)
• Streptococcus viridans
• Enterococcus faecalis
• Staphylococcus aureus (methicillin-sensitive strains)

Gram-negative bacteria:

• Haemophilus influenzae
• Moraxella catarrhalis
• Escherichia coli
• Proteus mirabilis
• Salmonella spp.
• Shigella spp.
• Neisseria gonorrhoeae
• Neisseria meningitidis
• Helicobacter pylori (in combination with other eradication drugs)

3. Resistance: Some bacteria may be resistant to ampicillin due to the production of beta-lactamases, an enzyme that hydrolyzes the beta-lactam ring of ampicillin and renders it inactive. Therefore, in some cases, ampicillin may be used in combination with a beta-lactamase inhibitor such as clavulanic acid to prevent the destruction of the antibiotic.

Pharmacokinetics

1. Absorption: Ampicillin is usually rapidly and completely absorbed from the gastrointestinal tract after oral administration. Absorption is improved when the drug is taken on an empty stomach.
2. Distribution: After absorption, ampicillin is widely distributed in tissues and body fluids, including lungs, middle ear, bile, urine, bones, skin and others. It also penetrates the placental barrier and is excreted in breast milk.
3. Metabolism: Ampicillin is not metabolized in the body. It acts as an antibacterial agent by inhibiting bacterial cell wall synthesis.
4. Excretion: Ampicillin is excreted from the body mainly by kidneys in unchanged form. Part of the drug is also excreted through the intestine.
5. Half-life: The half-life of ampicillin from the body is approximately 1-1.5 hours in adults. It may be longer in children.

Dosing and administration

Method of application

1. Oral administration (tablets, capsules, suspension):

• Tablets and capsules should be taken with water without chewing.
• The suspension should be shaken well before use.
• It is better to take ampicillin on an empty stomach, 30 minutes before a meal or 2 hours after a meal to improve its absorption.

2. Parenteral administration (injections):

• Dilute the powder with the recommended amount of water for injection.
• Injections may be intramuscular or intravenous, depending on your doctor's instructions.

Dosage

Dosage for adults:

1. For mild to moderate infections (orally):

   • 250-500 mg every 6 hours.

2. For severe infections (oral or parenteral):

   • 500 mg every 6 hours i.m. Or i.v.
   • Doses may be increased to 1 g every 6 hours depending on the severity of the infection.

3. Meningitis (parenteral):

   • 2 g every 4 hours IV.

4. Sepsis (parenteral):

   • 1-2 g every 4-6 hours w/v.

Dosage for children:

1. General infections (oral):

   • 25-50 mg/kg/day in divided doses every 6-8 hours.

2. Severe infections (parenterally):

   • 50-100 mg/kg/day in divided doses every 4-6 hours.
   • For meningitis, the dose may be increased to 200-400 mg/kg/day.

Duration of treatment:

• The duration of treatment depends on the type and severity of the infection and the patient's clinical response to therapy. The course of treatment is usually 7-14 days, but may be longer in case of meningitis or other severe infections.

Special Instructions

• It is important to complete the full course of treatment, even if symptoms improve, to prevent the bacteria from developing resistance.
• Ampicillin can cause stomach upset, so it should be taken with food if discomfort occurs.
• Patients should be monitored for allergic reactions, especially if there is a history of sensitivity to penicillins.

Use Ampicillin during pregnancy

The use of ampicillin during pregnancy should be carried out only under the supervision of a physician and after careful assessment of the benefits to the mother and potential risks to the fetus. The physician should decide whether to prescribe ampicillin, taking into account the clinical situation, safety and efficacy of the drug for the specific case.

Ampicillin belongs to category B of the FDA classification for use during pregnancy, which means that its safety for the fetus has not been fully established on the basis of controlled studies in humans, but there is no evidence of adverse effects on the fetus when used in pregnant animals. However, as with any drug, the risks and benefits must be carefully balanced for each individual situation.

Contraindications

1. Hypersensitivity: People with known hypersensitivity to ampicillin, other penicillins, or other beta-lactam antibiotics should avoid using this drug.
2. Mononucleosis-type infections: The use of ampicillin is not recommended in infections accompanied by mononucleosis syndrome due to the risk of urticaria.
3. Serious hepatic impairment: Patients with serious hepatic impairment should take ampicillin with caution or avoid its use.
4. Allergy: Patients with a history of allergic reactions to other beta-lactam antibiotics (e.g., cephalosporins or carbapenems) may be at increased risk of allergic reactions to ampicillin.
5. Diarrhea and superinfections: Use of antibiotics, including ampicillin, may cause diarrhea and increase the risk of superinfections.
6. Prolonged use: Prolonged use of ampicillin may lead to the development of resistance of microorganisms, therefore the drug should be used with caution and only when prescribed by a physician.
7. Children and adolescents: The use of ampicillin in children and adolescents requires special attention and supervision by a physician, especially with regard to dosage.
8. Pregnancy and breastfeeding: The use of ampicillin during pregnancy and breastfeeding may be authorized only if absolutely necessary and under medical supervision.

Side effects Ampicillin

1. Allergic Reactions:

   • Rash
   • urticaria
   • Itching
   • Quincke's edema (sudden and significant increase in tissue volume, most commonly of the face and neck)
   • Anaphylactic shock (rare, but it is a serious and potentially life-threatening condition)

2. Gastrointestinal disorders:

   • Nausea
   • Vomiting
   • Diarrhea
   • Abdominal pain
   • Pseudomembranous colitis (inflammation of the colon caused by antibiotics)

3. Liver dysfunction:

   • Increased liver enzymes
   • Jaundice (rare)

4. Effects on the hematopoietic system:

   • Leukopenia (decreased white blood cell count)
   • Neutropenia (decreased neutrophil count)
   • Anemia
   • Thrombocytopenia (decreased platelet count)

5. Nervous System:

   • Headache
   • Dizziness
   • Insomnia
   • Seizures (rare and usually in patients with renal impairment)

6. Other reactions:

   • Renal failure (rare)
   • Vaginal candidiasis
   • Oral candidiasis (thrush)

Overdose

1. Gastrointestinal disorders: Abrupt increase in side effects characteristic of ampicillin, such as nausea, vomiting, diarrhea and dyspepsia.
2. Allergic reactions: Possible development of allergic reactions such as urticaria, pruritus, facial edema, difficulty breathing and anaphylactic shock.
3. Liver and kidney disorders: Toxic effect on the liver and kidneys, which may manifest as an increase in the level of hepatic enzymes in the blood and signs of renal failure.
4. Neurological symptoms: Neurotoxic symptoms such as headache, dizziness, impaired consciousness and seizures.

Interactions with other drugs

1. Probenecid: Probenecid may slow the excretion of ampicillin, which may lead to an increase in its level in the blood and prolong its duration of action.
2. Methotrexate: Ampicillin may increase the toxicity of methotrexate, especially at high doses, by increasing its blood levels and exacerbating its side effects.
3. Antibiotics: Combining ampicillin with other antibiotics such as tetracyclines or macrolides may reduce the effectiveness of both drugs.
4. Anticoagulants: Ampicillin may increase the effect of anticoagulants such as warfarin, which may lead to increased clotting time and increased risk of bleeding.
5. Drugs affecting the digestive tract: Antacids, drugs containing iron, or drugs that slow intestinal peristalsis may reduce the absorption of ampicillin, which may lead to a decrease in its effectiveness.