penicillin v

REMS

Treatment of a wide variety of infections including:
- Pneumococcal pneumonia,
- Streptococcal pharyngitis,
- Syphilis,
- Gonorrhea strains.
Treatment of enterococcal infections (requires the addition of an aminoglycoside).
Prevention of rheumatic fever.
Should not be used as a single agent to treat anthrax.

Unlabeled Use:

Treatment of Lyme disease.
Prevention of recurrent Streptococcal pneumoniae septicemia in children with sickle-cell disease.

Action ⬆ ⬇

Bind to bacterial cell wall, resulting in cell death.

Therapeutic effects:

Bactericidal action against susceptible bacteria.

Spectrum:

Active against:
- Most gram-positive organisms, including many streptococci (Streptococcus pneumoniae, group A beta-hemolytic streptococci), staphylococci (non–penicillinase-producing strains) and Bacillus anthracis,
- Some gram-negative organisms, such as Neisseria meningitidis and N. gonorrhoeae (only penicillin susceptible strains),
- Some anaerobic bacteria and spirochetes including Borellia burgdorferi.

Pharmacokinetics ⬆ ⬇

Absorption: Variably absorbed from the GI tract. Resists acid degradation in the GI tract.

Distribution: Widely distributed, although CNS penetration is poor in the presence of normal (non-inflamed) meninges. Crosses the placenta and enters breast milk.

Protein Binding: 60%.

Metabolism/Excretion: Minimally metabolized by the liver, excreted mainly unchanged by the kidneys.

Half-Life: 30–60 min.

Time/Action Profile ⬆ ⬇

(blood levels)

ROUTE	ONSET	PEAK	DURATION
PO	rapid	0.5–1 hr	4–6 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Previous hypersensitivity to penicillins (cross-sensitivity exists with cephalosporins and other beta-lactam antibiotics);
Some products may contain tartrazine and should be avoided in patients with known hypersensitivity.

Use Cautiously in:

Severe renal impairment (dosage ↓ recommended);
OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk;
Lactation: Safety not established in lactation;
Geri: Consider ↓ body mass, age-related ↓ in renal/hepatic/cardiac function, concurrent diseases and drug therapy in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

Derm: rash, urticaria

GI: diarrhea, epigastric distress, nausea, vomiting, Clostridioides difficile-associated diarrhea (CDAD)

GU: interstitial nephritis

Hemat: eosinophilia, leukopenia

Neuro: SEIZURES

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS AND SERUM SICKNESS) , superinfection

Interactions ⬆ ⬇

Drug-drug:

Penicillin may ↓ effectiveness of oral contraceptive agents.
Probenecid↓ renal excretion and ↑ blood levels of penicillin (therapy may be combined for this purpose).
Neomycin may ↓ absorption of penicillin.
Concurrent use with methotrexate↓ methotrexate elimination and ↑ risk of serious toxicity.

Route/Dosage ⬆ ⬇

250 mg = 400,000 units
PO (Adults and Children ≥12 yr): Most infections: 125–500 mg every 6–8 hr. Rheumatic fever prevention: 125–250 mg every 12 hr.
PO (Children <12 yr): Lyme disease: 50 mg/kg/day in 4 divided doses (unlabeled); prevention of Streptococcus pneumoniaesepsis in children with sickle cell disease—125 mg twice daily.

Availability ⬆ ⬇

(Generic available)

Tablets: 250 mg; 500 mg
Powder for oral solution: 125 mg/5 mL; 250 mg/5 mL

Assessment ⬆ ⬇

Assess for infection (vital signs; appearance of wound, sputum, urine, and stool; WBC) at beginning of and during therapy.
Obtain a history to determine previous use of and reactions to penicillins, cephalosporins, or other beta-lactam antibiotics. Persons with a negative history of penicillin sensitivity may still have an allergic response.
Obtain specimens for culture and sensitivity before initiating therapy. First dose may be given before receiving results.
Observe patient for signs and symptoms of anaphylaxis (rash, pruritus, laryngeal edema, wheezing). Discontinue drug and notify physician or other health care professional immediately if these symptoms occur. Keep epinephrine, an antihistamine, and resuscitation equipment close by in case of an anaphylactic reaction.
Monitor bowel function. Diarrhea, abdominal cramping, fever, and bloody stools should be reported to health care professional promptly as a sign of Clostridioides difficile-associated diarrhea (CDAD). May begin up to several wk following cessation of therapy.

Lab Test Considerations:

May cause positive direct Coombs’ test results.
- May cause ↑ AST, ALT, LDH, and serum alkaline phosphatase concentrations.
- May cause leukopenia and neutropenia, especially with prolonged therapy or hepatic impairment.

Implementation ⬆ ⬇

Do not confuse penicillin with penicillamine.
PO: Administer around the clock. Penicillin V may be administered without regard for meals.
- Use calibrated measuring device for liquid preparations. Solution is stable for 14 days if refrigerated.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication around the clock and to finish drug completely as directed, even if feeling better. Advise patient that sharing this medication may be dangerous.
Advise patient to report signs of superinfection (black, furry overgrowth on tongue; vaginal itching or discharge; loose or foul-smelling stools) and allergy.
Instruct patient to notify health care professional if fever and diarrhea develop, especially if stool contains blood, pus, or mucus. Advise patient not to treat diarrhea without consulting health care professional.
Instruct patient to notify health care professional if symptoms do not improve.
Rep: Advise patient taking oral contraceptives to use an additional nonhormonal method of contraception during therapy with penicillin and until next menstrual period.
Patient with an allergy to penicillin should be instructed to always carry an identification card with this information.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇