Ampicillin (Generic)

Prescription medicineOnly Available By Prescription

Top Generic choice

Strength Pack Size Qty
Pack Size
Pack Size

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What if I find a lower price with another pharmacy?

We guarantee the lowest price on all of our prescription products. If you find your medications cheaper at any other recognized licensed mail order pharmacy, we will not only match their price, we will beat it by 25% of the difference. It is our 125% price match guarantee!

Example: If you find a product on Canada Drugs Direct for $50.00 and find the same product for $40.00 at another mail order pharmacy, we will provide you with a $12.50 discount, bringing your total to $37.50.

To get the discount please make sure to mention the price match to the customer service team when they call to collect payment for your order. Or call toll free at 1-888-904-8467 to place the order through the phone.

Terms & Conditions of Program

  • Guaranteed lowest price is only valid at the time of sale.
  • We will only match the current advertised price.
  • Products must be identical and in stock at the time of placing an order with a licensed mail order pharmacy. They must be an online Canadian pharmacy with an address in Canada.
  • Products must be authentic in brand and size (same manufacturer, same country of manufacture, same pack size, same strength and same quantity).
  • Products must be new. We cannot match the price of any used, short expiry or expired product.
  • Price match can only be issued over the phone with our customer service team. Please note at this time we cannot offer price matching for the products Ozempic or Saxenda.
What is a Generic Drug?

A generic drug is a copy of the brand-name drug with the same dosage, safety, strength, quality, consumption method, performance, and intended use. Before generics become available on the market, the generic company must prove it has the same active ingredients as the brand-name drug and works in the same way and in the same amount of time in the body.

The only differences between generics and their brand-name counterparts is that generics are less expensive and may look slightly different (eg. different shape or color), as trademarks laws prevent a generic from looking exactly like the brand-name drug.

Generics are less expensive because generic manufacturers don't have to invest large sums of money to develop a drug. When the brand-name patent expires, generic companies can manufacture a copy of the brand-name and sell it at a substantial discount.


Ampicillin is an oral antibiotic that can be prescribed for the following types of infections:

  • Gastrointestinal infections
  • Genitourinary infections
  • Respiratory tract infections

Ampicillin is often prescribed to complete a course of intravenous (IV) therapy when an infection has started to improve.

Ampicillin is a type of penicillin antibiotic. It works by preventing the formation of the cell wall that surrounds and protects certain types of bacteria. By stopping the construction of the cell wall, ampicillin kills bacteria and treats the infection.

Fact Table






62% ±17%

Legal status


Chemical Name


Elimination half-life

1 hour

Dosage (Strength)

250mg, 500mg


No Known Risk



Protein binding

15 to 25%

PubChem CID






ATC code






Routes of administration

By mouth


Take the Ampicillin doses exactly as prescribed by your healthcare provider. Do not stop the medication before completing the entire course, or bacterial resistance may develop.

Ampicillin is commonly taken three to four times daily.

Take Ampicillin on an empty stomach, 30 minutes before or 2 hours after meals. Drink a full glass of water after each dose. 


Ampicillin is a generic medication, and the active ingredient is ampicillin.


The most common drug-drug interactions with this medication include:

  • Allopurinol
  • Aminoglycosides
  • Atenolol
  • BCG
  • Chloroquine
  • Cholera vaccine
  • Dichlorphenamide
  • Lactobacillus and Estriol
  • Lanthanum
  • Methotrexate
  • Mycophenolate
  • Probenecid
  • Sodium picosulfate
  • Tetracycline
  • Typhoid vaccines
  • Warfarin

Tell your pharmacist and doctor about all medications you are taking before starting Ampicillin.


Do not take this medication if you have a known hypersensitivity to penicillin or similar medications. 

Call your doctor if you develop a rash while taking this medication.

Call your doctor if you develop severe and persistent diarrhea while on this medication.

Side Effects

Common Ampicillin side effects may include:

  • Agranulocytosis
  • Anemia
  • Diarrhea
  • Dysgeusia
  • Enterocolitis
  • Eosinophilia
  • Erythema multiforme
  • Exfoliative dermatitis
  • Fever
  • Glossalgia
  • Glossitis
  • Hemolytic anemia
  • Immune thrombocytopenia
  • Increased liver enzymes
  • Interstitial nephritis
  • Leukopenia
  • Melanoglossia
  • Nausea
  • Oral candidiasis
  • Penicillin-induced brain disease
  • Pseudomembranous colitis
  • Seizure
  • Serum sickness-like reaction
  • Skin rash
  • Sore mouth
  • Stomatitis
  • Stridor
  • Urticaria
  • Vomiting


  1. Ampicillin [package insert]. Princeton, NJ: Sandoz; 2020.

IMPORTANT NOTE: The above information is intended to increase awareness of health information and does not suggest treatment or diagnosis. This information is not a substitute for individual medical attention and should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. See your health care professional for medical advice and treatment.

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