What is it used for?
- Bacterial infections of the ear, nose and throat, eg otitis media, sinusitis.
- Bacterial infections of the urinary tract.
- Gynaecological infections, eg gonorrhoea.
- Bacterial infection of the blood (septicaemia or blood poisoning).
- Bacterial infections in the abdomen (peritonitis).
- Bacterial infections of the stomach and intestines.
- Bacterial infection of the heart valves and the lining surrounding the heart (bacterial endocarditis).
- Bacterial meningitis.
- Typhoid and paratyphoid fever.
How does it work?
Penbritin capsules and syrup contain the active ingredient ampicillin, which is a type of antibiotic called a penicillin. (NB. Ampicillin is also available without a brand name, ie as the generic medicine.) Ampicillin is used to treat infections caused by bacteria.
Ampicillin works by interfering with the ability of bacteria to form cell walls. The cell walls of bacteria are vital for their survival. They keep unwanted substances from entering their cells and stop the contents of their cells from leaking out. Ampicillin impairs the bonds that hold the bacterial cell wall together. This allows holes to appear in the cell walls and so kills the bacteria.
Ampicillin is a broad-spectrum antibiotic which kills a wide variety of bacteria that cause a wide variety of commonly-occuring infections. Ampicillin may be used to treat infections of the airways, ears, nose and throat. It may also be used to treat urine infections, certain sexually-transmitted infections, and certain infections affecting the blood or internal organs.
Ampicillin injection is used to treat more serious infections, or in cases where the medicine can't be taken by mouth.
To make sure the bacteria causing an infection are susceptible to ampicillin your doctor may need to take a tissue sample, for example a swab from the throat or skin, or a urine or blood sample.
How do I take it?
- The dose of this medicine and how long it needs to be taken for depends on the type and severity of infection you have, your age, weight and kidney function. Follow the instructions given by your doctor. These will be printed on the dispensing label that your pharmacist has put on the packet of medicine.
- Ampicillin is usually taken four times a day, but follow the instructions given by your doctor (urinary tract infections are treated with a dose three times a day and some infections only require one or two doses). You should try to space the doses evenly throughout the day.
- Ampicillin capsules and syrup should be taken on an empty stomach, which means either half an hour to an hour before food or two hours after food. This is because the presence of food in the gut prevents the antibiotic from being properly absorbed into the bloodstream and thus will make it less effective.
- The capsules should be swallowed with liquid.
- Bottles of syrup should be shaken before measuring out a dose. Only use the measuring spoon provided with the syrup. You should not use a regular teaspoon or tablespoon to give the medicine, as this will not give an accurate dose.
- Penbritin syrup should be stored in a refrigerator (2°C-8°C). Make sure the medicine is out of the reach of children. Any syrup remaining after 14 days should be disposed of, preferably by returning it to your pharmacist.
- Unless your doctor tells you otherwise, it is important that you finish the prescribed course of this antibiotic medicine, even if you feel better or it seems the infection has cleared up. Stopping the course early increases the chance that the infection will come back and that the bacteria will grow resistant to the antibiotic.
- Broad-spectrum antibiotics can sometimes cause inflammation of the bowel (colitis). For this reason, if you get diarrhoea that becomes severe or persistent or contains blood or mucus, either during or after taking this medicine, you should consult your doctor immediately.
Use with caution in
- Decreased kidney function.
- History of allergies.
- People with suspected glandular fever, acute or chronic lymphoid leukaemia, or cytomegalovirus (CMV), as the antibiotic commonly causes a rash in people with these conditions.
Not to be used in
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- There are no known harmful effects when this medicine is used during pregnancy.
- The medicine passes into breast milk in small amounts, but at normal doses it is unlikely to have any harmful effect on a nursing infant. Seek further medical advice from your doctor.
- Take this medication an hour before food or on an empty stomach.
- Take at regular intervals. Complete the prescribed course unless otherwise directed.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.
Prolonged treatment with antibiotics can sometimes cause overgrowth of other organisms that are not susceptible to the antibiotic, for example fungi or yeasts such as Candida. This may sometimes cause infections such as thrush. Tell your doctor if you think you have developed a new infection during or after taking this antibiotic.
- Rash or hives.
- Inflammation of the large intestine (colitis) - see warning section above.
- Allergic reaction to active ingredient.
- Severe allergic skin reactions.
- Disturbances in the number of white blood cells or platelets in the blood.
- Inflammation of the liver (hepatitis).
- Yellowing of the skin and eyes (jaundice).
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.
In the past, women using hormonal contraception such as the pill or patch would be advised to use an extra method of contraception (eg condoms) while taking an antibiotic like this one and for seven days after finishing the course. However, this advice has now changed. You no longer need to use an extra method of contraception with the pill, patch or vaginal ring while you take a course of antibiotics. This change in advice comes because to date there is no evidence to prove that antibiotics (other than rifampicin or rifabutin) affect these contraceptives. This is the latest guidance from the Faculty of Sexual & Reproductive Healthcare.
However, if you are taking the contraceptive pill and experience vomiting or diarrhoea as a result of taking this antibiotic, you should follow the instructions for vomiting and diarrhoea described in the leaflet provided with your pills.
Ampicillin may rarely alter the anti-blood-clotting effects of anticoagulant medicines such as warfarin. Your doctor may wish to monitor your blood clotting time (INR) more frequently while you are taking both medicines.
Ampicillin may decrease the removal of the medicine methotrexate from the body, which could increase the risk of its side effects. If you are taking methotrexate your doctor may want you to have extra check-ups and blood tests while you are taking a course of this antibiotic.
There may be an increased risk of experiencing a rash as a side effect of this medicine if you are also taking allopurinol.
Oral typhoid vaccine (Vivotif) should not be taken until at least three days after you have finished a course of this antibiotic, because the antibiotic could make the vaccine less effective.
Probenecid increases the blood level of ampicillin, and people taking probenecid may be prescribed a lower dose of ampicillin.
Other medicines containing the same active ingredient
Ampicillin capsules, suspension and injection are also available without a brand name, ie as the generic medicine.