Generic Principen (Ampicillin)

Drug Nomenclature

International Nonproprietary Names (INNs) in main languages (French, Latin, Russian, and Spanish):

Note. Compounded preparations of ampicillin may be represented by the following names: Co-fiuampicil (BAN)—flucloxacillin 1 part and ampicillin 1 part (w/w).

Pharmacopoeias

In Europe, Japan and Vietnam. International and US permit anhydrous or the trihydrate.

European Pharmacopoeia, 6th ed., 2008 and Supplements 6.1 and 6.2 (Ampicillin, Anhydrous; Ampicillin British Pharmacopoeia 2008). A white or almost white, crystalline powder. It exhibits polymorphism. Sparingly soluble in water; practically insoluble in alcohol, in acetone, and in fatty oils. It dissolves in dilute solutions of acids and of alkali hydroxides. A 0.25% solution in water has a pH of 3.5 to 5.5. Store at a temperature not exceeding 30° in airtight containers.

The United States Pharmacopeia 31, 2008 (Ampicillin). It is anhydrous or contains three molecules of water of hydration. A white, practically odourless crystalline powder. Slightly soluble in water and in methyl alcohol; insoluble in carbon tetrachloride, in chloroform, and in benzene. pH of a 1% solution in water is between 3.5 and 6.0. Store in airtight containers.

Ampicillin Sodium

Drug Nomenclature

INNs in main languages (French, Latin, Russian, and Spanish):

Pharmacopoeias

In China, Europe, International, Japan and US.

European Pharmacopoeia, 6th ed., 2008 and Supplements 6.1 and 6.2 (Ampicillin Sodium). A white or almost white hygroscopic powder. Freely soluble in water; sparingly soluble in acetone; practically insoluble in liquid paraffin and in fatty oils. A 10% solution in water has apH of 8.0 to 10.0. Store in airtight containers.

The United States Pharmacopeia 31, 2008 (Ampicillin Sodium). A white to off-white, odourless or practically odourless, hygroscopic, crystalline powder. Very soluble in water and in isotonic sodium chloride and glucose solutions. pH of a solution in water containing the equivalent of ampicillin 1% is between 8.0 and 10.0. Store in airtight containers.

Incompatibility

The incompatibility of ampicillin sodium and aminoglycosides is well established. Incompatibilities have also been reported with a wide range of other drugs, including other antibacterials, and appear to be more pronounced at higher concentrations and in solutions also containing glucose.

Stability

The stability of solutions of ampicillin sodium is dependent on many factors including concentration, pH, temperature, and the nature of the vehicle. Stability decreases in the presence of glucose, fructose, invert sugar, dextrans, hetastarch, sodium bicarbonate, and lactate. It is recommended that reconstituted solutions of ampicillin sodium for injection should be given within 24 hours of preparation, and should be stored at 2° to 8° but should not be frozen. Solutions for infusion are stable for varying periods and details are given in licensed product information.

Ampicillin Trihydrate

Drug Nomenclature

INNs in main languages (French, Latin, Russian, and Spanish):

Pharmacopoeias

In Europe and Vietnam. In China and Japan under the title Ampicillin. International and US permit anhydrous or the trihydrate under the title Ampicillin.

European Pharmacopoeia, 6th ed., 2008 and Supplements 6.1 and 6.2 (Ampicillin Trihydrate).

A white or almost white, crystalline powder. Slightly soluble in water; practically insoluble in alcohol and in fatty oils. It dissolves in dilute solutions of acids and of alkali hydroxides. A 0.25%) solution in water has a pH of 3.5 to 5.5. Store in airtight containers.

The United States Pharmacopeia 31, 2008 (Ampicillin).

It is anhydrous or contains three molecules of water of hydration. A white, practically odourless crystalline powder. Slightly soluble in water and in methyl alcohol; insoluble in carbon tetrachloride, in chloroform, and in benzene. pH of a 1%) solution in water is between 3.5 and 6.0. Store in airtight containers.

Adverse Effects

As for Benzylpenicillin.

Skin rashes are among the most common adverse effects and are generally either urticarial or maculopapular; the urticarial reactions are typical of penicillin hypersensitivity while the erythematous maculopapular eruptions are characteristic of ampicillin and amoxicillin and often appear more than 7 days after commencing treatment.

Such rashes may be due to hypersensitivity to the beta-lactam moiety or to the amino group in the side-chain, or to a toxic reaction. The occurrence of a maculopapular rash during ampicillin use does not necessarily preclude the subsequent use of other penicillins. However, since it may be difficult in practice to distinguish between hypersensitive and toxic responses, skin testing for hypersensitivity may be advisable before another penicillin is used in patients who have had ampicillin rashes.

Most patients with infectious mononucleosis develop a maculopapular rash when treated with ampicillin, and patients with other lymphoid disorders such as lymphatic leukaemia, and possibly those with HIV infection, also appear to be at higher risk.

More serious skin reactions may occur and erythema multiforme associated with ampicillin has occasionally been reported. Gastrointestinal adverse effects, particularly diarrhoea and nausea and vomiting, occur quite often, usually after oral use. Pseudomembranous colitis has also been reported.

Precautions

As for Benzylpenicillin. Ampicillin should be stopped if a skin rash occurs. It should preferably not be given to patients with infectious mononucleosis since they are especially susceptible to ampicillin-induced skin rashes; patients with lymphatic leukaemia or possibly HIV infection may also be at increased risk of developing skin rashes.

Myasthenia gravis

The symptoms of a woman with myasthenia gravis were exacerbated when she was given ampicillin.

Sodium content

Each g of ampicillin sodium contains about 2.7 mmol of sodium.

Interactions

As for Benzylpenicillin.

Allopurinol

An increased frequency of skin rashes has been reported in patients receiving ampicillin or amoxicillin, with allopurinol, compared with those receiving the antibacterial alone, but this could not be confirmed in a subsequent study Chloroquine.

The absorption of ampicillin has been reduced in healthy subjects taking chloroquine.

Antimicrobial Action

Ampicillin is a beta-lactam antibiotic. It is bactericidal and has a similar mode of action to that of benzylpenicillin, but as an aminopenicillin with an amino group side-chain attached to the basic penicillin structure, ampicillin is better able to penetrate the outer membrane of some Gram-negative bacteria and has a broader spectrum of activity.

Spectrum of activity

Ampicillin resembles benzylpenicillin in its action against Gram-positive organisms, including Streptococcus pneumoniae and other streptococci, but, with the possible exception of activity against Enterococcus faecalis, it is slightly less potent than benzylpenicillin. Listeria monocytogenes is highly sensitive. The Gram-negative cocci Moraxella catarrhalis (Branhamella catarrhalis), Neisseria gonorrhoeae, andN. meningitidis are sensitive.

Ampicillin is more active than benzylpenicillin against some Gram-negative bacilli, including Haemophilus influenzae and Enterobacteriaceae such as Escherichia coli, Proteus mirabilis, Salmonella and Shigella spp. It is inactive againstPseudomonas aeruginosa.

Ampicillin also has activity similar to benzylpenicillin against other organisms including many anaerobes and Actinomyces spp. Activity with other antimicrobials. There is synergy against some beta-lactamase-producing organisms between ampicillin and beta-lactamase inhibitors such as clavulanic acid or sulbactam, and also penicillinase-stable drugs such as cloxacillin or flucloxacillin.

Synergy has also been shown between ampicillin and aminoglycosides against a range of organisms, including enterococci.

Variable effects ranging from synergy to antagonism have been reported between ampicillin and other beta lactams, bacteriostatic drugs such as chloramphenicol, and rifampicin. Resistance. Like benzylpenicillin, ampicillin is inactivated by beta lactamases, although other mechanisms may be responsible for resistance in some species.

There are geographical variations in the incidence of resistance, but most staphylococci and many strains of E. coli, H. influenzae, M. catarrhalis, N. gonorrhoeae, and Salmonella and Shigella spp. are resistant.

Pharmacokinetics

Ampicillin is relatively resistant to inactivation by gastric acid and is moderately well absorbed from the gastrointestinal tract after oral doses. Food can interfere with the absorption of ampicillin so doses should preferably be taken at least 30 minutes before meals. Peak concentrations in plasma are attained in about 1 to 2 hours and after a 500-mg oral dose are reported to range from 3 to 6 micrograms/mL. Peak plasma concentrations of ampicillin after a 500-mg intramuscular dose given as the sodium salt occur within about 1 hour and are reported to range from 7 to 14 micrograms/mL.

Ampicillin is widely distributed and therapeutic concentrations can be achieved in ascitic, pleural, and joint fluids. It crosses the placenta and small amounts are distributed into breast milk.

There is little diffusion into the CSF except when the meninges are inflamed. About 20% is bound to plasma proteins and the plasma half-life is about 1 to 1.5 hours, but this may be increased in neonates, the elderly, and patients with renal impairment; in severe renal impairment half-lives of 7 to 20 hours have been reported. Ampicillin is metabolised to some extent to penicilloic acid which is excreted in the urine.

Renal clearance of ampicillin occurs partly by glomerular filtration and partly by tubular secretion; it is reduced by probenecid. About 20 to 40% of an oral dose may be excreted unchanged in the urine in 6 hours; urinary concentrations have ranged from 0.25 to 1 mg/mL after a dose of 500 mg. After parenteral use about 60 to 80% is excreted in the urine within 6 hours.

Ampicillin is removed by haemodialysis. High concentrations are reached in bile; it undergoes enterohepatic recycling and some is excreted in the faeces. Ampicillin with sulbactam. The pharmacokinetics of ampicillin and sulbactam are broadly similar and neither appears to affect the other to any great extent.

Uses and Administration

Ampicillin is used in the treatment of a variety of infections due to susceptible organisms (see Antimicrobial Action, above).

They include biliary-tract infections, bronchitis, endocarditis, gastro-enteritis (including salmonella enteritis and shigellosis), gonorrhoea, listeriosis, meningitis, perinatal streptococcal infections (intrapartum prophylaxis against group B streptococci), peritonitis, pneumonia, septicaemia, typhoid and paratyphoid fever, and urinary-tract infections.

Resistance to ampicillin is increasingly a problem in some infections, for example, gonorrhoea, pneumococcal infections, respiratory-tract infections due to Haemophilus influenzae or Moraxella catarrhalis (Branhamella catarrhalis), Salmonella infections, shigellosis, and infections due to Escherichia coli.

For details of these infections and their treatment, see under Choice of Antibacterial. If beta-lactamase-producing organisms are present, ampicillin can be given with a beta-lactamase inhibitor such as sulbactam (see below) or a penicillinase-resistant drug such as cloxacillin, dicloxacillin, or flucloxacillin (known as co-fluampicil). It may also be used with an aminoglycoside to increase the spectrum of organisms covered; it is advisable to give the injections separately.

Administration and dosage

The dosage of ampicillin will depend on the severity of the disease, the age of the patient, and renal function.

Ampicillin is usually given orally as the trihydrate and by injection as the sodium salt. Doses are expressed in terms of the equivalent amount of ampicillin; 1.06 g of ampicillin sodium and 1.15 g of ampicillin trihydrate are each equivalent to about 1 g of ampicillin.

The usual adult oral dose is 0.25 to 1 g every 6 hours taken at least 30 minutes before or 2 hours after food. Children may be given half the adult dose. The usual adult dose by injection is 500 mg every 4 to 6 hours intramuscularly or by slow intravenous injection over 3 to 5 minutes or by infusion. Again, children may be given half the adult dose. For urinary-tract infections, ampicillin 500 mg is given orally every 8 hours. For typhoid and paratyphoid fever where Salmonella typhi strains remain sensitive to ampicillin, an oral dose of 1 to 2 g may be given every 6 hours for 2 weeks for acute infections, and for 4 to 12 weeks in carriers. An intramuscular dose of 10 mg/kg (maximum dose 250 mg) every 6 hours for 4 to 6 weeks has been suggested for children who are chronic carriers.

Ampicillin 2 g given with probenecid 1 g, as a single oral dose, has been used in the treatment of uncomplicated gonorrhoea in areas where gonococci remain sensitive; repeated doses are recommended in females. In meningitis, higher parenteral doses of 2 to 3 g given intravenously every 4 or 6 hours have been suggested. For infants and children with meningitis, an intravenous dose of 150 mg/kg daily in divided doses may be given; a dose of 50 mg/kg (maximum 3 g) every 4 to 6 hours has also been suggested. Neonates may be given a dose of 50 mg/kg every 12 hours for those under 1 week of age, or every 8 hours for older neonates.

For intrapartum prophylaxis against group B streptococcal infection in the neonate, a maternal dose of 2 g by intravenous injection initially then 1 gevery4hours until delivery has been suggested. Ampicillin may also be given by other routes, usually as a supplement to systemic therapy. Intraperitoneal or intrapleural injections are given in a dose of 500 mg daily dissolved in 5 to 10 niL of water. For intra-artic-ular injection, ampicillin 500 mg daily is given dissolved in up to 5 niL of water or a solution of procaine hydrochloride 0.5%. Ampicillin benzathine has also been given by intramuscular injection.

Ampicillin with sulbactam

The sodium salts of ampicillin and sulbactam may be given intramuscularly or intravenously in the treatment of infections due to beta-lactamase-producing organisms. Doses are expressed in terms of the equivalent amounts of ampicillin and sulbactam; available injections contain ampicillin and sulbactam in the ratio 2:1, respectively. The usual dose is ampicillin 1 g with sulbactam 500 mg every 6 hours; doses may be doubled in severe infections. For oral use sultamicillin, a mutual prodrug of ampicillin and sulbactam, may be given.

Administration in renal impairment

The dose of ampicillin should be reduced, or the dose interval increased, in severe renal impairment (creatinine clearance less than 10 mL/minute). Patients undergoing dialysis should receive an additional dose after the session.

Preparations

British Pharmacopoeia 2008: Ampicillin Capsules; Ampicillin Injection; Ampicillin Oral Suspension; Co-fluampicil Capsules; Co-fluampicil Oral Suspension The United States Pharmacopeia 31, 2008: Ampicillin and Probenecid for Oral Suspension; Ampicillin and Sulbactam for Injection; Ampicillin Capsules; Ampicillin for Injectable Suspension; Ampicillin for Injection; Ampicillin for Oral Suspension; Ampicillin Tablets

Single-ingredient Preparations

Multi-ingredient Preparations