Ampicillin is a broad –spectrum that kills many more kinds of bacteria than other penicillin can kill. It is safer than other broad-spectrum antibiotics and is especially useful for babies and small children.

Because it is expensive and sometimes causes diarrhea or thrush, ampicillin should not be used when regular penicillin is likely to do the job as well.

Ampicillin works well when taken by mouth. Infections should only be used for severe illnesses such as meningitis, peritonitis and appendicitis or when the sick person vomits or cannot swallow the medicine. This drug is often useful in treating the following

  • Septicemia and unexplained illness in the newborn
  • Pneumonia or ear infections of children under 6 years
  • Meningitis
  • Peritonitis and appendicitis
  • Severe urinary tract infections
  • Typhoid fever (if it is resistant to chloramphenicol)
  • Gonorrhea

Persons allergic to penicillin should not take ampicillin



By mouth :

25 to 50 mg/kg/day : Capsules of 250 mg : syrup with 125 mg per teaspoon 5 ml


Give 4 doses a day and in each dose give:

  • Adult : 2 capsules or 4 teaspoons (500 mg)
  • Children ranging 8 to 12 years : 1 capsule or 2 teaspoons (250 mg)
  • Children 3 to 7 years : ½ capsule or 1 teaspoon (125 mg)
  • Children under 3 years : ¼ capsule or ½ teaspoon (62 mg)
  • Newborn babies : Same as for children under 3 years.

For gonorrhea, the doses are much higher.


By injection :

For severe infections (50 to 100 mg/kg/day- up to 300 mg/kg/day for meningitis vials of 500 mg


Give 4 doses a day, once every 6 hours and in each dose give:

  • Adult : 500 to 1000 mg (one to two 500 mg vials)
  • Children between 8 to 12 years : 250 mg.( ½ of a 500 mg vial)
  • Children between 3 to 7 years : 125 mg . (¼ of a 500 mg vial)
  • Children under 3 years : 62 mg. (1/8 of a 500 mg vial)
  • Newborn babies : 125 mg ¼ of a 500 mg vial) twice a day only

Keep giving the ampicillin for at least 2 days after signs of infection have gone.



Products that combine penicillin with streptomycin are found in most countries and are often used more than they should be.

Penicillin and streptomycin  should be used together only in special cases as an alternative to ampicillin, when ampicillin cannot be obtained or is too expensive. They should not be used for minor infections or for the common cold or flu.

Frequent use of streptomycin for illnesses other than tuberculosis makes the tuberculosis bacteria in a community resistant to streptomycin and therefore harder to treat. Also streptomycin may cause deafness.

Streptomycin with penicillin can be used for most of the illnesses for which ampicillin is recommended. But ampicillin is safer especially for babies. Usually, it is cheaper as well as easier to figure the correct dosage. If streptomycin and penicillin are injected separately rather than in a combination.



Give short acting penicillin at least 25,000 U/kg. 4 times a day and streptomycin , no more than 30 to 50 mg/kg/day.

In newborns, give short acting penicillin ; 500,000 U/kg. twice a day together with streptomycin, 20 mg/kg once a day.

ADULTS : 1,000,000 U. 4 to 6 times a day of penicillin and 1 gm (usually 2 ml) once a day of streptomycin.

CHILDREN BETWEEN 8 TO 12 YEARS : 500,000 U. 4 to 6 times a day of penicillin and 750 mg one and half of streptomycin once a day.

CHILDREN UNDER 3 TO 7 YEARS : 250,000 U. 4 to 6 times a day of penicillin and 500 mg (1 ml) of streptomycin once a day.

CHILDREN UNDER 3 YEARS : 125,000 U. 4 to 6 times a day of penicillin and 250 mg (half ml) of streptomycin once a day.

NEWBORN BABIES : 150,000 U. of penicillin twice a day and 60 mg 1/8 ml of streptomycin, once a day.


For very severe infections such as peritonitis, appendicitis, meningitis or an acute infection of the bone (osteomyelitis). Even higher doses of penicillin may be given but the dosage of streptomycin must never be higher than the amount suggested here.

For less severe infections calling for penicillin with streptomycin, procaine penicillin can be used with streptomycin.






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