Which is the most appropriate way to administer penicillin G procaine or penicillin G benzathine suspension?
The correct answer and explanation is:
Correct Answer: Intramuscular (IM) injection
Explanation (300 words):
Penicillin G procaine and penicillin G benzathine are long-acting forms of penicillin that are formulated as suspensions. These preparations are specifically designed for intramuscular (IM) administration only and should never be given intravenously due to the risk of serious, potentially fatal complications.
The IM route ensures a slow and sustained release of the drug into the bloodstream, which is essential for maintaining therapeutic levels over an extended period. This is particularly useful in the treatment of infections that require prolonged exposure to penicillin, such as:
- Syphilis (benzathine penicillin G is the first-line treatment)
- Rheumatic fever prophylaxis
- Streptococcal pharyngitis in certain populations
When these formulations are injected into a large muscle mass, such as the gluteus maximus or vastus lateralis, they create a depot effect. The drug is gradually absorbed, allowing for once-weekly or less frequent dosing, depending on the condition being treated.
Why not other routes?
- Intravenous (IV): Not appropriate. Administering these suspensions intravenously can cause severe adverse reactions, including cardiac arrest, seizures, and death, due to the particulate nature of the suspension blocking small vessels.
- Subcutaneous (SC): Not recommended. SC injection can lead to poor absorption, irritation, or local tissue damage due to the viscosity of the suspension.
- Oral: Not effective. These forms are not absorbed well through the gastrointestinal tract and lose their effectiveness if taken by mouth.
Summary:
The most appropriate and safe method for administering penicillin G procaine or penicillin G benzathine suspension is intramuscular injection, which ensures effective drug delivery while minimizing the risk of serious complications.