PRECAUTIONS

General

Penicillin should be used with caution in individuals with histories of significant allergies and/or asthma.

Prescribing penicillin V potassium tablets or penicillin V potassium for oral solution in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

The oral route of administration should not be relied upon in patients with severe illness, or with nausea, vomiting, gastric dilatation, cardiospasm, or intestinal hypermotility.

Occasionally patients will not absorb therapeutic amounts of orally administered penicillin.

In streptococcal infections, therapy must be sufficient to eliminate the organism (10 day minimum); otherwise the sequelae of streptococcal disease may occur. Cultures should be taken following completion of treatment to determine whether streptococci have been eradicated.

Prolonged use of antibiotics may promote the overgrowth of nonsusceptible organisms, including fungi. Should superinfection occur, appropriate measures should be taken.

Information for Patients

Patients should be counseled that antibacterial drugs, including penicillin V potassium tablets and penicillin V potassium for oral solution, should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When penicillin V potassium tablets or penicillin V potassium for oral solution are prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment, and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by penicillin V potassium tablets, penicillin V potassium for oral solution, or other antibacterial drugs in the future.

Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.

DOSAGE AND ADMINISTRATION

The dosage of penicillin V potassium tablets and penicillin V potassium for oral solution 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:

Streptococcal infections—mild to moderately severe—of the upper respiratory tract and including scarlet fever and erysipelas: 125 to 250 mg (200,000 to 400,000 units) every 6 to 8 hours for 10 days.

Pneumococcal infections—mild to moderately severe—of the respiratory tract, including otitis media: 250 to 500 mg (400,000 to 800,000 units) every 6 hours until the patient has been afebrile for at least 2 days.

Staphylococcal infections—mild infections of skin and soft tissue (culture and sensitivity tests should be performed): 250 to 500 mg (400,000 to 800,000 units) every 6 to 8 hours.

Fusospirochetosis (Vincent’s infection) of the oropharynx. Mild to moderately severe infections: 250 to 500 mg (400,000 to 800,000 units) every 6 to 8 hours.

For the prevention of recurrence following rheumatic fever and/or chorea: 125 to 250 mg (200,000 to 400,000 units) twice daily on a continuing basis.

For prophylaxis against bacterial endocarditis1 in patients with congenital heart disease or rheumatic or other acquired valvular heart disease when undergoing dental procedures or surgical procedures of the upper respiratory tract: 2 gram of penicillin V (1 gram for children under 60 lbs.) 1 hour before the procedure, and then, 1 gram (500 mg for children under 60 lbs.) 6 hours later.

Directions for Mixing Oral Solution

Do not add water until you dispense. When dispensing, tap bottle until all powder flows freely, slowly add the total amount of water for reconstitution (see table below). After partially filling bottle, replace cap and shake vigorously. Add remaining water and repeat shaking.After reconstitution, solution must be stored in a refrigerator. Discard any unused portion after 14 days.

125 mg/5 mL
Bottle size	Total Amount of Water Required for Reconstitution
100 mL	75 mL
200 mL	150 mL
The resulting solution (red in color) will contain penicillin V potassium equivalent to penicillin V 125 mg (200,000 units) in each 5 mL (teaspoonful).
250 mg/5 mL
Bottle size	Total Amount of Water Required for Reconstitution
100 mL	75 mL
200 mL	150 mL
The resulting solution (red in color) will contain penicillin V potassium equivalent to penicillin V 250 mg (400,000 units) in each 5 mL (teaspoonful).