Although the penicillins are virtually nontoxic to mammalian cells, there is a significant incidence of anaphylaxis in varying degrees. Reactions include skin rash, contact dermatitis, mild gastrointestinal upset, oral lesions, and fever. Because of the basic structure, there is a high degree of cross-sensitivity among the various forms.
Penicillin is effective in the treatment of:
ACTION AND USE. Penicillin G is indicated for susceptible infections as listed under the discussion of penicillins. It is available as a potassium or sodium salt and is for parenteral use only.
USUAL DOSE. The dosage varies with the infection. Doses of 10 million units or higher should be given by intravenous infusion only.
ACTION AND USE. Penicillin G procaine is indicated for deep intramuscular usage only in susceptible infections as listed under the discussion of penicillins. The action is more prolonged than penicillin G.
USUAL DOSE. For uncomplicated gonorrhea, 4.8 million units intramuscularly at two sites with 1 g of probenicid orally. Other dosages are as prescribed by the physician.
ACTION AND USE. This drug is indicated for deep intramuscular usage in susceptible infections. It has a longer duration of action than most of the other penicillins.
ACTION AND USE. Penicillin V is used in the treatment of susceptible infection as listed under the discussion of penicillins. It is available as oral tablets or powder for reconstitution for oral suspension. It is more stable in acid media than most of the other penicillins. It has the same spectra of activity of penicillin G and is usually the drug of choice for uncomplicated group A beta-hemolytic streptococcal infections.
ACTION AND USE. This drug is a penicillinase-resistant penicillin effective in treating penicillinase-producing staphylococci. It may be used to initiate therapy in any patient in whom a staphylococcal infection is suspected.
USUAL DOSE. 250 to 500 mg every 6 hours. It is available in capsules or powder form for oral suspension.
ACTION AND USE. Ampicillin is relatively stable in an acid medium and is readily absorbed after oral ingestion. It is effective against gramnegative and gram-positive cocci and some gramnegative bacilli. It is available in both oral and parenteral forms.
USUAL DOSE. The range is 250 to 500 mg every 6 hours, depending upon the diagnosis. For the parenteral dosage, normal saline is the recommended diluent.
ACTION AND USE. Methicillin is a penicillinase-resistant drug reserved for treatment of penicillinase-producing staphylococcal organisms. It is administered parenterally only.