prilocaine

Action and Spectrum

Actions and Spectrum: 

• prilocaine is a local anesthetic that blocks nerve impulses from specific body areas. The mechanism of action of prilocaine is similar to other local anesthetics such as lidocaine and bupivacaine. prilocaine works by binding to and blocking sodium channels in the nerve fibers, preventing the transmission of pain signals to the brain. 
• prilocaine has a broad spectrum of activity and can be used for various procedures, including dental work, minor surgery, and diagnostic procedures. It is beneficial for procedures that require a longer duration of anesthesia than lidocaine. prilocaine is less likely to cause allergic reactions than other local anesthetics like procaine. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Apprehension 

Nervousness 

Confusion 

Blurred vision 

Twitching 

Seizures 

Edema 

Status asthmaticus 

Anaphylactoid reactions (sometimes fatal) 

Anxiety 

Restlessness 

Disorientation 

Dizziness 

Tremors 

Shivering 

Black Box Warning

Contraindication / Caution

Contraindications/caution: 

Contraindications: 

• Allergy: prilocaine should not be used in patients with a known allergy to prilocaine or other local anesthetics like lidocaine, bupivacaine, or procaine. 
• Methemoglobinemia: prilocaine can cause methemoglobinemia, a condition where the blood cannot transport oxygen effectively. It should be avoided or used with caution in patients with a history of methemoglobinemia or a family history.
• Severe liver or kidney disease: prilocaine is metabolized in the liver and excreted in the kidneys, so it should be used cautiously in patients with severe liver or kidney disease. Dosing may need to be adjusted in these patients. 
• Heart problems: prilocaine can cause changes in heart rhythm, so it should be used cautiously in patients with heart problems or those taking medications that affect heart rhythm. 
• Pregnancy and breast-feeding: prilocaine should be used cautiously in pregnant or breastfeeding women. It is generally considered safe when used as directed, but dosing may need to be adjusted.

Caution: 

• Epinephrine sensitivity: prilocaine is often combined with epinephrine to prolong the duration of anesthesia and reduce bleeding during procedures. However, epinephrine can cause adverse reactions in some patients, including rapid heart rate, high blood pressure, and anxiety. Patients with a history of sensitivity to epinephrine should be monitored closely if prilocaine with epinephrine is used. 
• Drug interactions: prilocaine may interact with other medications, including beta-blockers and local anesthetics. Patients should inform their healthcare providers of their medications to avoid potential drug interactions. 
• Reduced clearance: prilocaine is metabolized in the liver and excreted in the kidneys. Patients with reduced liver or kidney function may require lower doses or more frequent monitoring to avoid potential side effects. 
• CNS depression: prilocaine can cause central nervous system (CNS) depression, including drowsiness and dizziness. Patients should be advised to avoid driving or operating heavy machinery until the effects of the medication wear off. 
• Allergic reactions: While rare, some patients may develop an allergic reaction to prilocaine. Signs of an allergic reaction include itching, rash, and difficulty breathing. Patients should seek medical attention immediately if they experience any of these symptoms. 

Pregnancy / Lactation

Pregnancy consideration: prilocaine should be used cautiously in pregnant women 

Pregnancy Category: C 

Lactation: Excretion of the drug in human breast milk is unknown 

Pregnancy category: 

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.   

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

prilocaine is a local anesthetic of the amide-type. It reversibly blocks nerve impulse transmission by inhibiting sodium ion influx through sodium-specific ion channels in the neuronal membrane. This prevents pain signals from being transmitted to the brain, resulting in numbness and reduced sensation in the area where the drug is applied. 

Pharmacodynamics: 

The pharmacodynamics of prilocaine involve its mechanism of action in the nervous system, specifically the blockade of voltage-gated sodium channels in neuronal membranes, which leads to the inhibition of nerve impulse transmission. 

As a local anesthetic, prilocaine selectively blocks the sodium channels in the nerve fibers of the tissue where it is administered. This prevents the initiation and propagation of action potentials in the nerve fibers, thus inhibiting the transmission of pain signals from the application site to the central nervous system. 

Pharmacokinetics: 

Absorption 

prilocaine is rapidly absorbed after injection or topical application. Adding vasoconstrictors, such as epinephrine, can delay the absorption and prolong the duration of action. 

Distribution 

prilocaine is moderately protein-bound (approximately 55%) and has a relatively small volume of distribution (0.6-4.4 L/kg). The onset of action of prilocaine depends on the mode of administration and the application site. For example, infiltration anesthesia typically lasts 2 minutes, while an inferior alveolar nerve block may take up to 3 minutes to take effect.  

Metabolism 

prilocaine is primarily metabolized in the liver, and to a lesser extent, in the kidneys, by the enzyme CYP1A2. It is converted to ortho-toluidine, which can cause methemoglobinemia in high doses. 

Elimination and Excretion 

prilocaine and its metabolites are primarily eliminated through the kidneys, with approximately 10% of the drug being excreted unchanged in the urine. The half-life of prilocaine is approximately 10-150 minutes, depending on the dose and route of administration. 

Adminstartion

Administration: 

prilocaine is primarily administered via injection, either as a subcutaneous or intramuscular injection, depending on the intended use and site of application. It is also available as a topical cream or gel for surface anesthesia. The specific administration method and dosage of prilocaine will depend on the intended use and the patient’s needs. 

For dental procedures, prilocaine is often administered as a local anesthetic by injection directly into the gum or around the affected tooth. The dosage will depend on the patient’s weight, age, and severity of the pain. The medication may be administered directly into the affected tissue or muscle in surgical procedures. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: prilocaine 

Why do we use prilocaine? 

prilocaine is a local anesthetic medication primarily used for its numbing effects. It is commonly used in various medical and dental procedures to reduce pain and discomfort, such as: 

• Dental procedures: prilocaine is often used for dental procedures, such as fillings, extractions, and root canals, to numb the area around the tooth and reduce pain. 
• Minor surgical procedures: prilocaine is also used in minor surgical procedures, such as skin biopsy or minor plastic surgery, to numb the area of the procedure. 
• Diagnostic procedures: prilocaine may be used for specific diagnostic procedures, such as a lumbar puncture or bone marrow aspiration, to reduce pain and discomfort during the procedure. 
• Pain management: prilocaine may be used as part of a pain management regimen to manage chronic pain, such as pain associated with arthritis or neuropathy. 
• Labor and delivery: prilocaine may be used as a local anesthetic during childbirth to reduce pain during episiotomies or other procedures. 
• Veterinary medicine: prilocaine is also used in veterinary medicine to provide local anesthesia during minor surgeries or dental work.