U.S. Brand Names:
Veetids®
Synonyms:
Pen VK; Phenoxymethyl Penicillin
Generic Available:
Yes
Canadian Brand Names:
Apo-Pen VK®; Nadopen-V®; Novo-Pen-VK; Nu-Pen-VK; PVF® K
Use:
Treatment of infections caused by susceptible organisms involving the respiratory tract, otitis media, sinusitis, skin, and urinary tract; prophylaxis in rheumatic fever
Use - Dental:
Antibiotic of first choice in treatment of common orofacial infections caused by aerobic gram-positive cocci and anaerobes. These orofacial infections include cellulitis, periapical abscess, periodontal abscess, acute suppurative pulpitis, oronasal fistula, pericoronitis, osteitis, osteomyelitis, postsurgical and post-traumatic infection. This agent is no longer recommended for dental procedure prophylaxis.
Pregnancy Risk Factor:
B
Lactation:
Enters breast milk (other penicillins are compatible with breast-feeding)
Contraindications:
Hypersensitivity to penicillin or any component of the formulation
Warnings/Precautions:
Use with caution in patients with severe renal impairment (modify dosage), history of seizures, or hypersensitivity to cephalosporins
Adverse Reactions:
>10%: Gastrointestinal: Mild diarrhea, vomiting, nausea, oral candidiasis
<1%: Convulsions, fever, hemolytic anemia, positive Coombs' reaction, acute interstitial nephritis, hypersensitivity reactions, anaphylaxis
Overdosage/Toxicology:
Symptoms of penicillin overdose include neuromuscular hypersensitivity (eg, agitation, hallucinations, asterixis, encephalopathy, confusion, and seizures). Electrolyte imbalance may occur if the preparation contains potassium or sodium salts, especially in renal failure. Hemodialysis may be helpful to aid in removal of the drug from blood; otherwise, treatment is supportive or symptom-directed.
Drug Interactions:
Aminoglycosides: May be synergistic against selected organisms
Methotrexate: Penicillins may increase the exposure to methotrexate during concurrent therapy; monitor.
Oral contraceptives: Anecdotal reports suggesting decreased contraceptive efficacy with penicillins have been refuted by more rigorous scientific and clinical data.
Probenecid, disulfiram: May increase penicillin levels
Tetracyclines: May decrease penicillin effectiveness
Warfarin: Effects of warfarin may be increased
Ethanol/Nutrition/Herb Interactions:
Food: Decreases drug absorption rate; decreases drug serum concentration.
Stability:
Refrigerate suspension after reconstitution; discard after 14 days
Mechanism of Action:
Inhibits bacterial cell wall synthesis by binding to one or more of the penicillin binding proteins (PBPs); which in turn inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.
Pharmacodynamics/Kinetics:
Absorption: 60% to 73%
Distribution: Enters breast milk
Protein binding, plasma: 80%
Half-life elimination: 30 minutes; prolonged with renal impairment
Time to peak, serum: 0.5-1 hour
Excretion: Urine (as unchanged drug and metabolites)
Dosage:
Oral:
Systemic infections:
Children <12 years: 25-50 mg/kg/day in divided doses every 6-8 hours; maximum dose: 3 g/day
Children 12 years and Adults: 125-500 mg every 6-8 hours
Prophylaxis of pneumococcal infections:
Children <5 years: 125 mg twice daily
Children 5 years and Adults: 250 mg twice daily
Prophylaxis of recurrent rheumatic fever:
Children <5 years: 125 mg twice daily
Children 5 years and Adults: 250 mg twice daily
Dosing interval in renal impairment: Clcr<10 mL/minute: Administer 250 mg every 6 hours
Administration:
Administer on an empty stomach to increase oral absorption
Monitoring Parameters:
Periodic renal and hematologic function tests during prolonged therapy; monitor for signs of anaphylaxis during first dose
Test Interactions:
False-positive or negative urinary glucose determination using Clinitest®; positive Coombs' [direct]; false-positive urinary and/or serum proteins
Dietary Considerations:
Take on an empty stomach 1 hour before or 2 hours after meals.
Patient Education:
Inform prescriber of all prescriptions, OTC medications, or herbal products you are taking, and any allergies you have. Do not take any new medication during therapy unless approved by prescriber. Take as directed at intervals around-the-clock, preferable on an empty stomach (1 hour before or 2 hours after a meal). Take entire prescription; do not skip doses or discontinue without consulting prescriber. Take a missed dose as soon as possible. If almost time for next dose, skip the missed dose and return to your regular schedule. Do not take a double dose. Maintain adequate hydration (2-3 L/day of fluids) unless instructed to restrict fluid intake. If you have diabetes, drug may cause false test results with Clinitest®, consult prescriber for alternative method of glucose monitoring. May cause nausea or vomiting (small, frequent meals, frequent mouth care, chewing gum, or sucking lozenges may help); or diarrhea (buttermilk, boiled milk, or yogurt may help). Report persistent adverse effects; signs of opportunistic infection (eg, fever, chills, unhealed sores, white plaques in mouth or vagina, purulent vaginal discharge, fatigue); or signs of hypersensitivity reaction (rash, hives, itching, swelling of lips, tongue, mouth, or throat).
Additional Information:
0.7 mEq of potassium per 250 mg penicillin V; 250 mg equals 400,000 units of penicillin
Dental Health: Effects on Dental Treatment:
Key adverse event(s) related to dental treatment: Oral candidiasis (prolonged use).
Dental Health: Vasoconstrictor/Local Anesthetic Precautions:
No information available to require special precautions
Mental Health: Effects on Mental Status:
Penicillins reported to cause apprehension, illusions, hallucinations, depersonalization, agitation, insomnia, and encephalopathy
Mental Health: Effects on Psychiatric Treatment:
None reported
Dosage Forms:
Note: 250 mg = 400,000 units
Powder for oral solution: 125 mg/5 mL (100 mL, 200 mL); 250 mg/5 mL (100 mL, 200 mL)
Tablet: 250 mg, 500 mg
International Brand Names:
Apo-Pen VK® (CA); Nadopen-V® (CA); Novo-Pen-VK (CA); Nu-Pen-VK (CA); PVF® K (CA)
References
Dajani AS, Bisno AL, Chung KJ, et al, "Prevention of Rheumatic Fever. A Statement for Health Professionals by the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young, The American Heart Association,"Pediatr Infect Dis J, 1989, 8(5):263-6.
Wynn RL and Bergman SA, "Antibiotics and Their Use in the Treatment of Orofacial Infections, Part I and Part II,"Gen Dent, 1994, 42(5):398-402, 498-502.