Procaine benzylpenicillin also known as penicillin G procaine, is an

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

useful for the treatment of a number of bacterial infections. Specifically it is used for

syphilis Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms depend on the stage it presents: primary, secondary, latent syphilis, latent or tertiary. The prim ...

anthrax Anthrax is an infection caused by the bacterium '' Bacillus anthracis'' or ''Bacillus cereus'' biovar ''anthracis''. Infection typically occurs by contact with the skin, inhalation, or intestinal absorption. Symptom onset occurs between one ...

, mouth infections,

pneumonia Pneumonia is an Inflammation, inflammatory condition of the lung primarily affecting the small air sacs known as Pulmonary alveolus, alveoli. Symptoms typically include some combination of Cough#Classification, productive or dry cough, ches ...

diphtheria Diphtheria is an infection caused by the bacteria, bacterium ''Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild Course (medicine), clinical course, but in some outbreaks, the mortality rate approaches 10%. Signs a ...

cellulitis Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of ...

, and animal bites. It is given by injection into a muscle. Side effects include pain at the site of injection, blood clotting problems,

seizures A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

, and

allergic reaction Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...

s including

anaphylaxis Anaphylaxis (Greek: 'up' + 'guarding') is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of the use of emergency medication on site. It typicall ...

. When used to treat syphilis a Jarisch–Herxheimer reaction may occur. It is not recommended in those with a history of penicillin allergy or procaine allergy. Use during

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

and

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

is relatively safe. Procaine benzylpenicillin is in the

penicillin Penicillins (P, PCN or PEN) are a group of beta-lactam antibiotic, β-lactam antibiotics originally obtained from ''Penicillium'' Mold (fungus), moulds, principally ''Penicillium chrysogenum, P. chrysogenum'' and ''Penicillium rubens, P. ru ...

and beta lactam family of medications. It works via benzylpenicillin and results in bacterial death. Procaine makes the combination long acting. Procaine benzylpenicillin was introduced for medical use in 1948. It is on the World Health Organization's List of Essential Medicines.

Medical uses

Specific indications for procaine penicillin include: *

Syphilis Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms depend on the stage it presents: primary, secondary, latent syphilis, latent or tertiary. The prim ...

** In the United States, Bicillin C-R (an injectable suspension which 1.2 million units of benzathine penicillin and 1.2 million units of procaine penicillin per 4 ml) is not recommended for treating syphilis, since it contains only half the recommended dose of benzathine penicillin. Medication errors have been made due to the confusion between Bicillin L-A & Bicillin C-R. As a result, changes in product packaging have been made; specifically, the statement "Not for the Treatment of Syphilis" has been added in red text to both the Bicillin CR and Billin CR 900/300 syringe labels. *

Respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of conducting air to the alveoli for the purposes of gas exchange in mammals. The respiratory tract is lined with respiratory epithelium as respirato ...

infections where compliance with oral treatment is unlikely * Alongside Pen V and Erythromycin, Bicillin C-R is used to treat

strep throat Streptococcal pharyngitis, also known as streptococcal sore throat (strep throat), is pharyngitis (an infection of the pharynx, the back of the throat) caused by ''Streptococcus pyogenes'', a Gram-positive bacteria, gram-positive, group A str ...

, given as one IM injection *

Cellulitis Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of ...

erysipelas Erysipelas () is a relatively common bacterial infection of the superficial layer of the skin ( upper dermis), extending to the superficial lymphatic vessels within the skin, characterized by a raised, well-defined, tender, bright- red rash, ...

* Procaine penicillin is also used as an adjunct in the treatment of

Adverse effects

At high doses procaine penicillin can cause seizures and CNS abnormalities due to procaine present in it.

Mechanism

It is a form of

which is a salt of benzylpenicillin and the

local anaesthetic A local anesthetic (LA) is a medication that causes absence of all sense, sensation (including pain) in a specific body part without loss of consciousness, providing local anesthesia, as opposed to a general anesthetic, which eliminates all sen ...

agent procaine. The salt has weak solubility, and is prepared as a suspension. Upon injection it forms a deposit within tissue (a " depot'), and the salt slowly dissolves into

interstitial fluid In cell biology, extracellular fluid (ECF) denotes all body fluid outside the Cell (biology), cells of any multicellular organism. Body water, Total body water in healthy adults is about 50–60% (range 45 to 75%) of total body weight; women ...

- dissociating the two molecules into their bioactive forms over an extended period. Procaine acts as a local anaesthetic to reduce the discomfort of the depot, while benzylpenicillin enters into circulation and binds to bacterial cell walls, inhibiting their upkeep and production. This eventually leads to cell lysis (bursting). The term "hydrolyzed" is incorrectly used in some medical literature to describe the dissociation of the salt and resulting benzylpenicillin, but this is inaccurate - the molecules themselves are unchanged and no water is consumed in the reaction. The products are the two oppositely charged bioactive molecules.

Compendial status

British Pharmacopoeia The ''British Pharmacopoeia'' (''BP'') is the national pharmacopoeia of the United Kingdom. It is an annually published collection of quality standards for medicinal substances in the UK, which is used by individuals and organisations involve ...

References

External links