Dosing & Uses
Dosage Forms & Strengths
premixed injectable solution
- 1 million units/50mL
- 2 million units/50mL
- 3 million units/50mL
potassium, powder for injectable solution
- 5 million units/vial
- 20 million units/vial
sodium, powder for injectable solution
- 5 million units/vial
Meningococcal Meningitis/Septicemia
20-30 million units/day IV continuous infusion x14 days or afebrile x7days, OR
200,000-300,000 units/kg/day IV divided q2-4hr x24 doses
Actinomycosis
Cervicofacial cases: 1-6 million units/day IV
Thoracic and abdominal disease: 10-20 million units/day IV divided q4-6hr x 6 weeks, may follow with penicillin V
Botulism
Adjunctive to antitoxin: 20 million units/day IV divided q4-6hr
Vincent’s Infection (fusospirochetosis)
5-10 million units/day IV divided q4-6hr
Rat-Bite Fever
Indicated for Streptobacillus moniliformis and Spirillum minus (rat-bite fever)
12-20 million units/day IV divided q4-6hr x3-4 weeks
Listeria Infections
Meningitis: 15-20 million units/day IV divided q4-6hr x2 weeks
Endocarditis: 15-20 million units/day IV divided q4-6hr x4 weeks
Pasteurella Infections
Bacteremia or meningitis: 4-6 million units/day IV divided q4-6hr x2 weeks
Erysipeloid
Endocarditis: 12-20 million units/day IV divided q4-6hr x4-6 weeks
Diphtheria
Adjunct to antitoxin or to prevent carrier state: 2-3 million units/day IV divided q4-6hr x10-12 days
Anthrax
Minimum: 5 million units/day IV
12-20 million units/day IV have been used
Streptococcal Infections
Empyema, pneumonia, pericarditis, endocarditis, meningitis: 5-24 million units/day IV divided q4-6hr
Syphilis
Neurosyphilis: 18-24 million units/day IV x10-14 days
Streptococcal Group B Infection
Prophylaxis: 5 million units IV at the onset of labor or after membrane rupture followed by 2.5 million units IV q4hr until delivery
Lyme Disease (Off-label)
200,000-300,000 units/kg/day IV x 10-14 days
Renal Impairment
CrCl 10-50 mL/min: Decrease dose by 25%
CrCl <10 mL/min: Decrease dose by 50-70%
Hemodialysis: Removed by hemodialysis; administer after dialysis
Dosage Forms & Strengths
premixed injectable solution
- 1 million units/50mL
- 2 million units/50mL
- 3 million units/50mL
potassium, powder for injectable solution
- 5 million units/vial
- 20 million units/vial
sodium, powder for injectable solution
- 5 million units/vial
Neonatal Bacterial Infection General Dosing Guidlines
<7 days & <2000 g: 50,000 units/kg/day IV divided q12hr
<7 days & >2000 g: 75,000 units/kg/day IV divided q8hr
>7 days & <1200 g: 50,000 units/kg/day IV divided q12hr
>7 days & 1200-2000 g: 75,000 units/kg/day IV divided q8hr
>7 days & >2000 g: 100,000 units/kg/day IV divided q6hr
Infant & Children Bacterial Infection General Dosing Guidelines
Moderate Infection: 25,000-50,000 units/kg/day IV/IM divided q6hr
Severe Infection: 250,000-400,000 units/kg/day IV/IM divided q4-6hr
Not to exceed 24 million units/day
Meningitis
Neonates <7 days & <2000 g: 100,000 units/kg/day IV divided q12hr
Neonates <7 days & >2000 g: 150,000 units/kg/day IV divided q8hr
Neonates >7 days & <1200 g: 100,000 units/kg/day IV divided q12hr
Neonates >7 days & 1200-2000 g: 150,000 units/kg/day IV divided q8hr
Neonates >7 days & >2000 g: 200,000 units/kg/day IV divided q6hr
Infants & Children: 250,000-400,000 units/kg/day IV divided q4hr; not to exceed 24 million units/day
Group B Streptococcal Meningitis
Neonates <7 days: 250,000-450,000 units/kg/day IV divided q8hr
Neonates >7 days: 450,000 units/kg/day IV divided q6hr
Congenital Syphilis
Neonates <7 days: 100,000 units/kg/day IV divided q12hr
Neonates >7 days: 150,000 units/kg/day IV divided q8hr
Endocarditis
Infants and Children <45 kg: 250,000 units/kg/day IV divided q4hr
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (10)
- BCG vaccine live
penicillin G aqueous decreases effects of BCG vaccine live by pharmacodynamic antagonism. Contraindicated. Wait until Abx Tx complete to administer live bacterial vaccine.
- cholera vaccine
penicillin G aqueous, cholera vaccine. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Avoid coadministration of cholera vaccine with systemic antibiotics since these agents may be active against the vaccine strain. Do not administer cholera vaccine to patients who have received oral or parenteral antibiotics within 14 days prior to vaccination.
- demeclocycline
demeclocycline decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Avoid or Use Alternate Drug.
- doxycycline
doxycycline decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Avoid or Use Alternate Drug.
- microbiota oral
penicillin G aqueous decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores. Antibacterial agents may decrease efficacy if coadministered. Complete antibiotic regimens 2-4 days before initiating microbiota oral. .
- minocycline
minocycline decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Avoid or Use Alternate Drug.
- omadacycline
omadacycline decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Tetracyclines may interfere with the bactericidal action of penicillins. Monitor for decreased therapeutic effects of penicillins if concomitantly used with a tetracycline.
- sarecycline
sarecycline decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Tetracyclines may interfere with the bactericidal action of penicillins. Monitor for decreased therapeutic effects of penicillins if concomitantly used with a tetracycline.
- tetracycline
tetracycline decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Avoid or Use Alternate Drug.
- typhoid vaccine live
penicillin G aqueous decreases effects of typhoid vaccine live by pharmacodynamic antagonism. Contraindicated. Wait until Abx Tx complete to administer live bacterial vaccine.
Monitor Closely (22)
- amifampridine
penicillin G aqueous increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.
- amiloride
penicillin G aqueous increases effects of amiloride by unspecified interaction mechanism. Use Caution/Monitor. Hyperkalemia.
- aspirin
penicillin G aqueous, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
penicillin G aqueous, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor. - aspirin rectal
penicillin G aqueous, aspirin rectal. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
penicillin G aqueous, aspirin rectal. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor. - aspirin/citric acid/sodium bicarbonate
penicillin G aqueous, aspirin/citric acid/sodium bicarbonate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
penicillin G aqueous, aspirin/citric acid/sodium bicarbonate. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor. - bazedoxifene/conjugated estrogens
penicillin G aqueous will decrease the level or effect of bazedoxifene/conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- choline magnesium trisalicylate
penicillin G aqueous, choline magnesium trisalicylate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
penicillin G aqueous, choline magnesium trisalicylate. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor. - deflazacort
penicillin G aqueous and deflazacort both decrease serum potassium. Use Caution/Monitor.
- dienogest/estradiol valerate
penicillin G aqueous will decrease the level or effect of dienogest/estradiol valerate by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor. An alternate or additional form of birth control may be advisable during concomitant use.
- ethinylestradiol
penicillin G aqueous decreases levels of ethinylestradiol by increasing metabolism. Use Caution/Monitor. Risk of oral contraceptive failure.
- fostemsavir
fostemsavir will increase the level or effect of penicillin G aqueous by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- hydrochlorothiazide
penicillin G aqueous, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- ibuprofen IV
penicillin G aqueous, ibuprofen IV. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
penicillin G aqueous, ibuprofen IV. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor. - neomycin PO
neomycin PO decreases levels of penicillin G aqueous by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- pretomanid
pretomanid will increase the level or effect of penicillin G aqueous by Other (see comment). Modify Therapy/Monitor Closely. In vitro studies demonstrated that pretomanid significantly inhibits OAT3; monitor for increased adverse effects and consider dosage reduction for OAT3 substrates.
- probenecid
probenecid increases levels of penicillin G aqueous by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.
- rose hips
penicillin G aqueous, rose hips. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- salicylates (non-asa)
penicillin G aqueous, salicylates (non-asa). Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
- salsalate
penicillin G aqueous, salsalate. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
- sodium phenylacetate
penicillin G aqueous, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- sodium picosulfate/magnesium oxide/anhydrous citric acid
penicillin G aqueous decreases effects of sodium picosulfate/magnesium oxide/anhydrous citric acid by altering metabolism. Use Caution/Monitor. Coadministration with antibiotics decreases efficacy by altering colonic bacterial flora needed to convert sodium picosulfate to active drug.
- willow bark
penicillin G aqueous, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
Minor (12)
- azithromycin
azithromycin decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Minor/Significance Unknown.
- chloramphenicol
chloramphenicol decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Minor/Significance Unknown.
- chlorothiazide
chlorothiazide increases levels of penicillin G aqueous by decreasing renal clearance. Minor/Significance Unknown.
- clarithromycin
clarithromycin decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Minor/Significance Unknown.
- erythromycin base
erythromycin base decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Minor/Significance Unknown.
- erythromycin ethylsuccinate
erythromycin ethylsuccinate decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Minor/Significance Unknown.
- erythromycin lactobionate
erythromycin lactobionate decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Minor/Significance Unknown.
- erythromycin stearate
erythromycin stearate decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Minor/Significance Unknown.
- furosemide
furosemide increases levels of penicillin G aqueous by decreasing renal clearance. Minor/Significance Unknown.
- hydrochlorothiazide
hydrochlorothiazide increases levels of penicillin G aqueous by decreasing renal clearance. Minor/Significance Unknown.
- methyclothiazide
methyclothiazide increases levels of penicillin G aqueous by decreasing renal clearance. Minor/Significance Unknown.
- roxithromycin
roxithromycin decreases effects of penicillin G aqueous by pharmacodynamic antagonism. Minor/Significance Unknown.
Adverse Effects
Frequency Not Defined
Seizure
Anemia
Interstitial nephritis
Hypersensitivity
Anaphylaxis
Jarisch-Herxheimer reaction
Positive Coombs' reaction
Warnings
Contraindications
Allergy to penicillins, cephalosporins, imipenem
Cautions
Serious and occasionally fatal hypersensitivity (anaphylactic) reactions reported; reactions likely to occur in individuals with a history of penicillin hypersensitivity and/or a history of sensitivity to multiple allergens; before initiating therapy, inquire about previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens; discontinue and institute appropriate therapy If an allergic reaction occurs
Severe cutaneous adverse reactions (SCAR), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP) reported when SCAR is suspected, discontinue therapy and consider an alternative treatment
The use of antibiotics may promote overgrowth of nonsusceptible organisms, including fungi; indwelling intravenous catheters encourage superinfections; should superinfection occur, appropriate measures should be taken; when indicated, incision and drainage or other surgical procedures should be performed in conjunction with antibiotic therapy
Care should be taken to avoid intravenous or accidental intraarterial administration, or injection into or near major peripheral nerves or blood vessels, since such injections may produce neurovascular damage; particular care should be taken with IV administration because of possibility of thrombophlebitis
Skipping doses or not completing the full course of therapy may decrease the effectiveness of the immediate treatment and increase the likelihood that bacteria will develop resistance and will not be treatable by Penicillin G Potassium for Injection, USP or other antibacterial drugs in the future
In renal/hepatic impairment, reduce dose based on severity of impairment
Clostridium difficile
- Clostridium difficile associated diarrhea (CDAD) reported; may range in severity from mild diarrhea to fatal colitis; CDAD must be considered in all patients who present with diarrhea following antibiotic use; may occur over two months after administration of antibacterial agents
- If suspected or confirmed, discontinue ongoing antibiotic use not directed against C. difficile; administer appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be institute as clinically indicated
Pregnancy & Lactation
Pregnancy Category: B
Lactation: excreted in breast milk
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Half-Life: 20-50 min (ESRD 3-5 hr)
Peak Plasma Time: IM 30 min, IV 1 hr
Protein Bound: 65%
Distribution: crosses placenta, poor blood brain barrier diffusion
Metabolism: hepatic to active metabolites
Excretion: urine
Mechanism of Action
Interferes with synthesis of cell wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible microorganisms.
Administration
IV Incompatibilities
Additive: floxacillin, quinidine
Syringe: heparin
Y-site: aminophylline, cefamandole, cefazolin(?), heparin, Na bicarb
IV Compatibilities
Additive: dobutamine, lidocaine, KCl, procainamide, propafenone, verapamil
Y-site: cefazolin(?), clarithromycin, dobutamine, dopamine, erythromycin, gentamicin, lidocaine, morphine, norepinephrine, KCl, vancomycin
IV Preparation
Rapid loading: 150 mg/100 mL D5W (1.5 mg/mL)
Slow infusions: 900 mg/500 mL D5W (1.8 mg/mL)
IV Administration
If infusion >2 hr: use glass or polyolefin bottles
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
---|---|---|---|
penicillin G sodium injection - | 5 million unit vial | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
penicillin G sodium injection
PENICILLIN G - INJECTION
(pen-ih-SILL-in GEE)
COMMON BRAND NAME(S): Pfizerpen
USES: This medication is used to treat a wide variety of bacterial infections. It is also used to prevent infection of the heart (bacterial endocarditis) in patients with certain heart diseases who are having surgery. This medication is known as a natural penicillin antibiotic. It works by stopping the growth of bacteria.
HOW TO USE: Depending on your specific product, this medication is given by injection into a vein or into a muscle. Use exactly as directed by your doctor. The dosage is based on your medical condition and response to therapy. For children, the dosage is also based on weight.If you are giving this medication to yourself at home, learn all preparation and usage instructions from your health care professional. Before using, check this product visually for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely.Give aminoglycosides (such as gentamicin) separately from this medication. Do not mix together in the same IV fluid.For the best effect, use this antibiotic at evenly spaced times. To help you remember, use this medication at the same time(s) every day.Continue to use 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: Pain/redness/swelling at injection site may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.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: joint/muscle pain, muscle weakness, swelling of ankles/feet, dark/cloudy urine, extreme tiredness, fast/slow/irregular heartbeat, new signs of infection (such as sore throat that doesn't go away, fever), easy bruising/bleeding, signs of kidney problems (such as change in the amount of urine), numbness/tingling of arms/legs, seizures, uncontrolled movements, confusion.If used to treat syphilis or other spirochetal infections (such as Lyme disease), this medication may cause a condition known as Jarisch-Herxheimer reaction. This condition may occur 1 to 2 hours after you receive the medication and can last up to 24 hours. Notify your doctor right away if you experience any of these symptoms: fever/chills, muscle pain, worsening of skin sores, fast heartbeat, fast breathing, dizziness, flushing.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. 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), 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 using this medication, tell your doctor or pharmacist if you are allergic to it; or to penicillin or cephalosporin antibiotics; or if you have any other allergies. This product may contain inactive ingredients (such as corn for products containing dextrose), 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: asthma, kidney disease.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.Certain products of this medication contain sodium. Consult your doctor or pharmacist if you are on a salt-restricted diet or if you have a condition that could be worsened by an increase in salt intake (such as heart failure).Certain products of this medication contain potassium. Consult your doctor or pharmacist if you are taking potassium supplements, salt substitutes containing potassium, or medications that can increase potassium (including ACE inhibitors such as lisinopril), or if you have a high potassium level (hyperkalemia).Older adults may be at greater risk for side effects while using this drug.Newborns and infants may be at greater risk for side effects while using this drug.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 include: "blood thinners" (such as warfarin), methotrexate, NSAIDS (such as aspirin, indomethacin), tetracyclines.Low-dose aspirin should be continued if prescribed by your doctor for specific medical reasons such as heart attack or stroke prevention (usually 81-162 milligrams a day). Ask your doctor or pharmacist for more details.This medication may interfere with certain lab tests (such as certain urine glucose 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. Canada residents can call a provincial poison control center. Symptoms of overdose may include: seizures, confusion, mental/mood changes (such as agitation).
NOTES: Lab and/or medical tests (such as kidney function, complete blood count, potassium/sodium levels) may be done while you are using this medication. Keep all medical and lab appointments. Consult your doctor for more details.
MISSED DOSE: It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule. Do not double the dose to catch up.
STORAGE: Consult the product instructions and your pharmacist for storage details. 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.
Information last revised October 2023. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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