Penicillin V Potassium
Indications And Clinical Uses: Mild to moderately severe infections caused by penicillin V sensitive microorganisms including streptococcal pharyngitis, staphylococcal infection without bacteremia and pneumococcal infections. Therapy should be guided by bacteriologic sensitivity tests and clinical response.
For prophylaxis following rheumatic fever and/or chorea. (Prophylaxis with oral penicillin on a continuing basis has proved effective in preventing recurrences of these conditions.) To prevent bacterial endocarditis in patients with congenital and/or rheumatic heart lesions before dental procedures, minor upper respiratory tract surgery or instrumentation. Prophylaxis should be instituted the day of the procedure and continued for 2 or more postoperative days. Patients with a past history of rheumatic fever who are receiving continuous antibiotic prophylaxis may harbour increased numbers of penicillin resistant organisms; use of another anti-infective agent should be considered. If penicillin is to be used in these patients during surgery, the regular rheumatic fever program should be interrupted 1 week before the procedure. At the time of surgery, penicillin may be reinstituted prophylactically.
For the prevention of bacteremia following tooth extraction.
Contra-Indications: Oral penicillin should not be used as adjunctive prophylaxis for genitourinary instrumentation or surgery, lower intestinal tract surgery, sigmoidoscopy and childbirth; in patients with a history of penicillin or cephalosporin allergy; against beta lactamase (penicillinase) producing organisms; the active treatment of syphilis; subacute bacterial endocarditis, diphtheria, gas gangrene, or other severe infections due to penicillin-susceptible organisms.
Precautions: Serious and occasionally fatal hypersensitivity (anaphylactoid) reactions have been reported in patients receiving penicillin therapy. Although anaphylaxis is more frequent following parenteral therapy, it has occurred with oral penicillins. These reactions are more apt to occur in individuals with a history of sensitivity to multiple allergens.
Careful inquiry should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins and other allergens. Effective and safe skin tests which will predict an anaphylactic reaction are not generally available. Cross sensitivity between penicillin and cephalosporins is well documented.
Penicillin should be used with caution in individuals with histories of allergies and/or asthma.
Oral administration should not be relied on in patients with severe illness, with nausea, vomiting, gastric dilatation, cardiospasm, or intestinal hypermotility.
Occasional patients will not absorb therapeutic amounts of oral penicillin.
In streptococcal infections, therapy should be given for 10 days minimum. Cultures should be taken following treatment to assure eradication of streptococci.
Prolonged use of antibiotics may promote overgrowth of nonsusceptible organisms, including fungi. Should superinfection occur, take appropriate measures.
Adverse Reactions: Although the incidence of reactions to oral penicillins is much lower than to parenteral therapy, all degrees of hypersensitivity including fatal anaphylaxis have been reported.
The most common reactions to oral penicillin are nausea, vomiting, epigastric distress, diarrhea, and black hairy tongue. The hypersensitivity reactions reported are skin eruptions (maculopapular to exfoliative dermatitis), urticaria; reactions resembling serum sickness, including chills, fever, edema, and anaphylaxis. Fever and eosinophilia may frequently be the only reactions observed. Hemolytic anemia, leukopenia, thrombocytopenia, neuropathy, and nephropathy may occur but are usually associated with high doses of parenteral penicillin.
Symptoms And Treatment Of Overdose: Symptoms and Treatment: Anaphylactic shock must be treated with epinephrine 0.3 mL of 1:1 000 solution given by the i.v. or i.m. route in repeated doses until relief of bronchospasm and hypotension has occurred or excessive tachycardia has been induced. Mild hypersensitivity reactions may respond to antihistamines.
Dosage And Administration: The dosage should be determined according to the sensitivity of the causative microorganisms and the severity of infection and adjusted to the clinical response of the patient.
The usual dosage recommendations for adults and children 12 years and over are as follows:
Beta hemolytic streptococcal infections – mild to moderately severe (without associated bacteremia) of the upper respiratory tract including scarlet fever and mild erysipelas: 200 000 to 500 000 units 3 times a day for a minimum of 10 days to prevent development of rheumatic fever. Dosage for routine prophylaxis against streptococcal infection in patients with a history of rheumatic fever or congenital heart disease may be 200 000 units once or twice daily. When such patients undergo tonsillectomy, tooth extraction or other minor surgery the prophylactic dose should be 500 000 units every 6 hours 2 days before surgery and 2 days postoperatively. If oral medication is not feasible on the day of surgery, parenteral therapy should be given.
Pneumococcal infections – mild to moderately severe infections of the respiratory tract including otitis media: 400 000 to 500 000 units every 6 hours until the patient has been afebrile for at least 2 days.
Staphylococcal infections – mild infections of the skin and soft tissue (culture and sensitivity tests should be performed): 400 000 to 500 000 units every 6 to 8 hours in conjunction with the indicated surgical procedure.
Fusospirochetosis (Vincent’s Angina) of the oropharynx, mild to moderately severe infections: 400 000 to 500 000 units every 6 to 8 hours.
Prophylaxis in the following conditions – to prevent recurrence following rheumatic fever and/or chorea: 200 000 to 250 000 units twice daily on a continuing basis.
To prevent bacterial endocarditis in patients with rheumatic or congenital heart lesions before dental or upper respiratory tract surgery or instrumentation: i.m. penicillin is more reliable. However, if oral penicillin is preferred, penicillin V 2 g, one hour prior to the surgical procedure, then 1.0 g six hours later is recommended by the American Heart Association (1984). For practical purposes, 7 tablets of 300 mg (3.5 million units), one hour prior to surgery, then 3 1/2 tablets of 300 mg (1.75 million units) could be given.
Pediatric doses: penicillin V full adult dose if greater than 27 kg (60 lb); one-half adult dose if less than 27 kg (60 lb).
Availability And Storage: Oral Solution: Nadopen-V 200: After reconstitution, each 5 mL of red, strawberry flavored solution contains: penicillin V potassium 125 mg (200 000 IU). Energy: 57.9 kJ (13.64 kcal). Sodium: trace. Bottles of 100 mL.
Nadopen-V 400: After reconstitution, each 5 mL of red, strawberry flavored solution contains: penicillin V potassium 250 mg (400 000 IU). Energy: 55.25 kJ (13.0 kcal). Sodium: trace. Bottles of 100 mL.
Tablets: Each peach colored, round, scored tablet, engraved with the Nadeau logo and the figure 300, contains: penicillin V potassium 300 mg (500 000 IU). Sodium: trace. Bottles of 100, 500 and 1 000.
NADOPEN-V® Nadeau Penicillin V Potassium Antibiotic