Penicillin G (Pfizerpen) is an antibiotic used to treat a wide variety of bacterial infections. It's typically given as an injection or infusion in the hospital or provider's office. Since it doesn't last long in the body, it usually needs to be given multiple times a day.
Streptococcus and some staphylococcus infections, including pneumonia and meningitis
Actinomyces infections
Clostridium infections (add-on treatment), including botulism and tetanus
Diphtheria (add-on treatment)
Listeria infections
Pasteurella infections
Haverhill fever and rat-bite fever
Certain gonococcal infections
Meningococcal infections, including meningitis and sepsis
Gram-negative bacteria infections (e.g., salmonella)
Penicillin G (Pfizerpen) an antibiotic that kills bacteria by preventing them from making their own protective covering.
Source: DailyMed
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Stop taking this medicine and get emergency help immediately if any of the following effects occur:
Less common
Fast or irregular breathing
joint pain
lightheadedness or fainting (sudden)
puffiness or swelling around the face
red, scaly skin
shortness of breath
Check with your doctor immediately if any of the following side effects occur:
Rare
Abdominal or stomach cramps and pain (severe)
abdominal tenderness
convulsions (seizures)
decreased amount of urine
diarrhea (watery and severe), which may also be bloody
mental depression
pain at place of injection
sore throat and fever
unusual bleeding or bruising
yellow eyes or skin
Rare
For penicillin G procaine only
Agitation or combativeness
confusion
fear of impending death
feeling, hearing, or seeing things that are not real
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Make sure to finish the entire course of penicillin G (Pfizerpen) as prescribed by your provider, even if you're feeling better. Stopping antibiotics too early can cause your infection to come back or be harder to treat.
Penicillin G (Pfizerpen) is typically given as an intravenous (IV) infusion, but it can also be injected into the muscle. Your provider will decide how you should get this medication.
Penicillin G (Pfizerpen) can cause you to have an allergic reaction. These reactions can happen immediately (usually within 20 minutes after the start of treatment) or later (usually within 1 to 2 weeks after the start of treatment). Tell your provider or get medical help right away if you have a rash, itchy skin, trouble breathing, or swelling in your lips, tongue, or face after taking penicillin G (Pfizerpen).
Penicillin G (Pfizerpen) interacts with certain medications including aspirin, indomethacin (Indocin), and furosemide (Lasix). If taken together, these other medications can raise the penicillin G (Pfizerpen) levels in your body and put you at higher risk for side effects. Make sure your provider and pharmacists know all of the medications you are using.
Penicillin G (Pfizerpen) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Risk factors: History of allergy to penicillin or cephalosporin antibiotics | History of asthma
Penicillin G (Pfizerpen) can cause allergic reactions that can be deadly. If you've had an allergy to any penicillin or cephalosporin antibiotic in the past, tell your provider before taking penicillin G (Pfizerpen). Get medical help right away if you experience trouble breathing, chest tightness, or swelling of your lips, tongue, or face.
Risk factors: Long-term use of antibiotics | Taking other antibiotics
Sometimes antibiotics including penicillin G (Pfizerpen) can lead to a new infection caused by too much C. difficile bacteria growing in your gut. This infection can cause serious diarrhea that can be life-threatening, and it's important you get treated with different antibiotics. If you experience fever, stomach cramps, or diarrhea, even after you stop taking penicillin G (Pfizerpen), let your provider know right away.
Risk factors: Intravenous (IV) catheter
Penicillin G (Pfizerpen) can kill good bacteria in your body and promote the growth of other bacteria or fungi. This can lead to new infections. You're at a higher risk if you have an IV catheter (a tube inserted in your vein so you can get IV medications). Tell your provider if you have a fever, muscle pain, chills, or feel unwell while taking penicillin G (Pfizerpen) so you can be checked and treated for any new infections that happen.
Penicillin G (Pfizerpen) is usually given as an intravenous (IV) or intramuscular (IM) injection in a hospital setting or at home by a healthcare provider. Your provider will make sure you get this medication at the correct dose and time.
The dose depends on the condition being treated. In children, the dose will also depend on their weight.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these medicines, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Streptococcus and some staphylococcus infections, including pneumonia and meningitis
Actinomyces infections
Clostridium infections (add-on treatment), including botulism and tetanus
Diphtheria (add-on treatment)
Listeria infections
Pasteurella infections
Haverhill fever and rat-bite fever
Certain gonococcal infections
Meningococcal infections, including meningitis and sepsis
Gram-negative bacteria infections (e.g., salmonella)
Lower respiratory tract infections (e.g., pneumonia, bronchitis)
Urinary tract infections (UTIs)
Skin infections (e.g., cellulitis)
Bloodstream infections
Preventing infection from surgery
Skin infections (e.g., cellulitis)
Gynecological infections (e.g., vaginal, cervical, pelvic inflammatory disease)
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