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Prescription vs.OTC: Prescription by Doctor required
Last Updated: July 19, 2019

Ampicillin is an antibiotic so it is used to fight bacterial infections. It is a semi-synthetic derivative of penicillin and is used to treat urinary tract infections, pneumonia, respiratory track infections, meningitis, or gonorrhea, infections of the stomach or intestines.

Inform your doctor know if you are pregnant or planning to be pregnant during the course of this medicine. It is advised to avoid Ampicillin if –

  • you have been allergic towards any penicillin antibiotic.
  • you are taking tetracycline antibiotics or mononucleotic medicines.
  • you have recently received or will be receiving any immunisation of vaccination.

Ampicillin is less toxic than other antibiotics. Side effects are rare and hardly occur. They include nausea, vomiting, high level of eosinophils, skin rashes, swelling of tongue and diarrhoea. Serious but rare side effects include dark urine, abdominal pain, jaundice, easy bruising or bleeding, persistent sore throat or fever.

The dosage of this medicine as prescribed by your doctor depends on your age, your kidney function, and the type of bacteria causing the infection. It is taken usually 4 times a day in every 6 hours, or as directed by a doctor. Unnecessary use or overuse of this medicine will decrease its effectiveness.

Information given here is based on the salt and content of the medicine. Effect and uses of medicine may vary from person to person. It is advicable to consult a Internal Medicine Specialist before using this medicine.

  • Bacterial Meningitis

    Ampicillin is used in the treatment of meningitis, which is an inflammation of the protective membranes that surround the brain and spinal cord, caused by Streptococcus pneumoniae and Neisseria meningitidis.
  • Respiratory Tract Infection

    Ampicillin is used in the treatment of respiratory tract infections like pneumonia and brochitis, caused by Streptococcus pneumoniae and Staphylococcus aureus.
  • Endocarditis

    Ampicillin is used in the treatment of Endocarditis which is an inflammation of inner layer of heart caused by Streptococcus species: Staphylococci, and Enterococci.
  • Bacterial Septicemia

    Ampicillin is used in the treatment of Septicemia which is an infection of the blood caused by Staphylococci and Streptococcus pyogenes.
  • Urinary Tract Infection

    Ampicillin is used in the treatment of infections of the urinary tract caused by E.coli, Pseudomonas aeruginosa, Enterococci and Klebsiella pneumoniae.
  • Allergy

    Ampicillin is not recommended if a patient is highly allergic to ampicillin or other antibiotics of Penicillins and Cephalosporins groups.
  • How long is the duration of effect?

    The effect of this medicine lasts for an average duration of 3 to 6 hours.
  • What is the onset of action?

    The peak effect of this medicine can be observed in 1 to 2 hours after an oral dose.
  • Are there any pregnancy warnings?

    This medicine is not known to cause any harm to the fetus. But the evidence is inadequate and it should be used only when necessary after consulting a doctor.
  • Is it habit forming?

    No habit forming tendencies have been reported.
  • Are there any breast-feeding warnings?

    This medicine is safe to use during breastfeeding. Any incidence of rashes on skin or diarrhea in the infant should be reported. It is advised to consult a doctor before taking this medicine.
  • Missed Dose instructions

    The missed dose should be taken as soon possible. It is advisable to skip the missed dose if it's already time for your next scheduled dose.
  • Overdose instructions

    Seek emergency medical treatment or contact the doctor in case of overdose.
  • India

  • United States

  • Japan

Below is the list of medicines, which contains Ampicillin as ingredient

Ampicillin belongs to Aminopenicillins. it works by inhibiting the bacterial cell wall synthesis thus inhibiting the growth and multiplication of the bacteria.

Whenever you take more than one medicine, or mix it with certain foods or beverages, you"re at risk of a drug interaction.

  • Interaction with Disease

    Impaired kidney function

    The blood concentration of intravenous Ampicillin may increase in patients suffering from impaired kidney functioning. Suitable dose adjustments are to be made based on the severity of kidney function. Frequent monitoring of kidney function tests is necessary.


    Ampicillin should be discontinued if severe diarrhea occurs. Patients having a history of Colitis should be monitored closely.
  • Interaction with Alcohol


    Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.
  • Interaction with Lab Test


    Information not available.
  • Interaction with Food


    The absorption of Ampicillin may decrease in the presence of food. For proper absorption of the medicine, it should be taken at least 1 hour before or 2 hours after meals.
  • Interaction with Medicine


    The effect of atenolol will decrease in the presence of Ampicillin. Low doses of Ampicillin can be given based on the condition. Frequent monitoring of blood pressure is necessary. Any signs of increased blood pressure or kidney function impairment should be reported to the doctor.


    The effect of Ampicillin will decrease in the presence of chloroquine. Inform the doctor if you are receiving these two medications. A time gap of 2 hours should be maintained between these two doses.


    The effect of Ampicillin will decrease in the presence of doxycycline. Inform the doctor if you are receiving these two medications. An alternate medicine should be prescribed based on the clinical condition.


    Ampicillin may increase the blood levels of methotrexate especially when large doses are given. Any symptoms of nausea, vomiting, mouth ulcers and low blood cell counts should be reported to the doctor. If coadministration is necessary, then suitable dose adjustments should be made or other antibiotics should be considered based on the clinical condition.


    The effect of warfarin will increase in the presence of Ampicillin especially in the elderly population with kidney or liver injury. Any symptoms of bleeding, blood in vomiting or stools should be reported to the doctor. Frequent monitoring of blood cell count is necessary.

Ques: What is Ampicillin?

Ans: Ampicillin is a medication which has Ampicillin as an active ingredient present in it. This medicine performs its action by obstructing the release of bacterias in bacterial cell wall. Ampicillin is used to avoid respiratory tract infections and endocarditis symptoms. It is used to treat conditions such as Meningitis, urinary tract infections, pneumonia, bronchitis, bacterial infections and Septicemia.

Ques: What are the uses of Ampicillin?

Ans: Ampicillin is used for the treatment and prevention from conditions and symptoms of diseases like Meningitis, urinary tract infections, pneumonia, bronchitis and Septicemia. Besides these, it can also be used to treat conditions like respiratory tract infections and endocarditis. The patient should inform the doctor about any ongoing medications and treatment before using Ampicillin to avoid undesirable effects.

Ques: What are the Side Effects of Ampicillin?

Ans: This is a list of possible side-effects which may occur due to the constituting ingredients of Ampicillin. This is not a comprehensive list. These side-effects have been observed and not necessarily occur. Some of these side-effects may be serious. These include nausea, vomiting, anemia and headache. Apart from these, using Ampicillin may further lead to hypersensitivity reactions, Thrombocytopenia and diarrhea. If any of these symptoms occur often or on daily basis, a doctor should be urgently consulted.

Ques: What are the instructions for storage and disposal Ampicillin?

Ans: Ampicillin should be stored at room temperature, away from heat and direct light. Keep it away from the reach of children and pets. A doctor should be consulted regarding the dosage of Ampicillin. The patient should consult a doctor for its further uses and side effects and should inform the doctor about any ongoing medications and treatment before using to avoid undesirable effects.

Ques: Should I use Ampicillin empty stomach, before food or after food?

Ans: The consumption of this medication is done orally. If you take this medication with the food, the reactions that took place in the body carry outs in a much effective manner. Your stomach might get upset if you take this medication on an empty stomach. It is advised to consult a doctor before taking Ampicillin.

Ques: How long do I need to use Ampicillin before I see improvement of my conditions?

Ans: The time taken by this medication to improve your health is unknown. Thus it is advised to use this medication for the time period it is prescribed by your doctor. Using this medication longer then its prescribed time may cause some side effects to the patient. Please consult your doctor before using Ampicillin.

Ques: Is there any food or drink I need to avoid?

Ans: The diet should be normal, there is nothing as such to avoid. However, eating healthy, doing physical exercises and avoiding any kind of harmful practices like smoking or drinking can uplift your health.

Ques: Will Ampicillin be more effective if taken in more than the recommended dose?

Ans: Please follow the doses of the medication, as prescribed by your doctor. If you take more than the recommended doses of Ampicillin, it may cause some side effects. It is advised to ask your doctor to re-examine your condition if the severity in the health is not reducing.
Disclaimer: The information produced here is best of our knowledge and experience and we have tried our best to make it as accurate and up-to-date as possible, but we would like to request that it should not be treated as a substitute for professional advice, diagnosis or treatment.

Lybrate is a medium to provide our audience with the common information on medicines and does not guarantee its accuracy or exhaustiveness. Even if there is no mention of a warning for any drug or combination, it never means that we are claiming that the drug or combination is safe for consumption without any proper consultation with an expert.

Lybrate does not take responsibility for any aspect of medicines or treatments. If you have any doubts about your medication, we strongly recommend you to see a doctor immediately.

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Table of Content
About Ampicillin
What are the uses of Ampicillin
What are the contraindications of Ampicillin ?
What are the side effects of Ampicillin ?
Key highlights of Ampicillin
What are the dosage instructions?
Where is the Ampicillin approved?
Medicines containing Ampicillin
How does medicine works?
What are the interactions of Ampicillin ?
Ampicillin Frequently Asked Questions (FAQs):