How is Bicillin CR (Penicillin G benzathine; Penicillin G procaine) administered?

Bicillin CR, which contains Penicillin G benzathine and Penicillin G procaine, is administered via intramuscular (IM) injection. This route is specifically chosen for this medication due to several factors.

Firstly, the intramuscular administration allows for a depot effect, where the medication is gradually released into the bloodstream over time. This is particularly beneficial for treating certain infections that require sustained therapeutic levels of the antibiotic.

Secondly, the formulation of Bicillin CR involves the combination of two types of penicillin — benzathine provides a long duration of action, while procaine offers a more immediate effect. The IM route facilitates the absorption of these compounds, leading to their effectiveness in treating conditions such as strep throat or rheumatic fever.

In contrast, oral administration would not ensure sufficient drug levels for treating more serious infections, and intravenous continuous infusion is typically used for medications that require rapid and controlled dosing, which is not the purpose of Bicillin CR. Similarly, subcutaneous injections are not suitable for this particular formulation, as they do not provide the same absorption characteristics that intramuscular injections do in this context.