Uses
Penicillin is an antibiotic used to treat and prevent a wide variety of bacterial infections. It works by stopping the growth of bacteria.
This antibiotic treats and prevents only bacterial infections. It will not work for virus infections (such as the common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.
How To Use
Take this medication by mouth as directed by your doctor. This medication may be taken with or without food. However, penicillin is best absorbed when taken on an empty stomach (1 hour before or 2 hours after meals).
The dosage is based on your medical condition and response to treatment.
For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.
Continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may result in a return of the infection.
Tell your doctor if your condition lasts or gets worse.
Side Effects
Upset stomach, nausea, vomiting, diarrhea, and mouth sores may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Although this effect is uncommon, you may develop a black, "hairy" tongue while taking this medication. This effect is harmless and usually goes away after treatment. Maintain good oral hygiene, and brush your tongue with a soft toothbrush twice a day. Consult your doctor or pharmacist for more information.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including:
- unusual tiredness
- joint/muscle pain
- easy bruising/bleeding
This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop:
- diarrhea that doesn't stop
- abdominal or stomach pain/cramping
- blood/mucus in your stool
If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.
Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection (oral or vaginal fungal infection). Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge or other new symptoms.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:
- rash
- itching/swelling (especially of the face/tongue/throat)
- new fever
- severe dizziness
- trouble breathing
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Precautions
Before taking penicillin, tell your doctor or pharmacist if you are allergic to it; or to other antibiotics including penicillin-type medications (such as amoxicillin, ampicillin) or cephalosporins (such as cephalexin, cefuroxime); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of:
Penicillin may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using penicillin before having any immunizations/vaccinations.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
This drug passes into breast milk. Consult your doctor before breast-feeding.
Drug Interactions
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug are:
- methotrexate
- tetracyclines
- khat
- guar gum
This medication may interfere with certain lab tests (such as certain diabetic urine tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.
Overdose
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Alberta residents can call PADIS (Poison and Drug Information Service) 24 hours a day at 1-800-332-1414. Canada residents can call a provincial poison control center. Symptoms of overdose may include: diarrhea that doesn't stop, severe vomiting.
Notes
Do not share this medication with others.
This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor tells you to.
With long term treatment, lab and/or medical tests (such as kidney function, complete blood counts) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
If you have questions about missing a dose or you don't have more medication, contact your healthcare provider or pharmacist.
Storage
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.