dibucaine topical ointment

Action and Spectrum

Actions and Spectrum 

Action: 

Local Anesthesia: dibucaine works by blocking nerve signals in the area where it is applied. It acts as a sodium channel blocker, preventing the conduction of nerve impulses. This action temporarily inhibits the sensation of pain and discomfort in the affected area. 

Spectrum:  

Local Pain Relief: The ointment can be applied topically to the skin to alleviate pain associated with minor cuts, burns, insect bites, or skin irritations. 

Itching and Allergic Reactions: dibucaine can provide relief from itching caused by conditions like insect bites, poison ivy, or other allergic reactions. 

Hemorrhoids: The ointment is commonly used to alleviate pain and discomfort associated with hemorrhoids (swollen blood vessels in the rectum or anus). 

Drug Interaction

Adverse Reaction

Frequency not defined  

Chest pain 

Palpitations 

Diarrhea 

Eye/skin irritation 

Photosensitivity 

Contact dermatitis 

Flushing 

Black Box Warning

Black Box Warning: 

None  

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Individuals who have a known hypersensitivity or allergy to dibucaine or other local anesthetics should avoid using dibucaine topical ointment. 

Severe liver disease: dibucaine is metabolized by the liver, so individuals with severe liver disease may have difficulty metabolizing the drug properly. The potential for harmful side effects or systemic toxicity may be enhanced as a result of this. 

Broken or damaged skin: Applying dibucaine topical ointment on injured or broken skin, such as open wounds or severe burns, is not recommended. The absorption of dibucaine through broken skin can lead to systemic toxicity or other complications.  

Methemoglobinemia: dibucaine can cause a rare condition called methemoglobinemia,it can reduce the ability of red blood cells to carry oxygen, leading to symptoms such as shortness of breath, headache, dizziness, and bluish discoloration of the skin. Individuals with a history of methemoglobinemia or those who are at increased risk should avoid using dibucaine topical ointment.  

Eye contact: It is crucial to avoid any contact between the eyes and dibucaine topical ointment. Such contact may lead to irritation and possible harm to the sensitive tissues of the eyes. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: C 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

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 

dibucaine, also known as dibucaine hydrochloride or cinchocaine, is a local anesthetic commonly used in topical ointment formulations. It belongs to the class of drugs called as amide-type local anesthetics. 

Pharmacodynamics:  

dibucaine acts by inhibiting the conduction of nerve impulses in the area where it is applied. It does this by blocking the sodium channels on the nerve cell membranes, which are responsible for the propagation of nerve impulses. By blocking these channels, dibucaine prevents the transmission of pain signals from reaching the brain, thereby providing local anesthesia and reducing pain and itching.   

Pharmacokinetics: 

Absorption 

it is primarily absorbed through the skin. The absorption rate can vary depending on factors such as the concentration of the ointment, the area of application, and the integrity of the skin. 

Distribution  

dibucaine is distributed throughout the body via the bloodstream. However, when used as a topical ointment, the systemic distribution is minimal compared to when it is administered by injection or orally.  

Metabolism 

dibucaine undergoes metabolism in the liver. It is primarily metabolized by enzymes known as cytochrome P450 (CYP450) enzymes, particularly the CYP1A2 and CYP3A4 enzymes.  

Excretion and Elimination 

The metabolites of dibucaine, along with a small amount of unchanged dibucaine, are excreted primarily through urine. The elimination half-life of dibucaine is relatively short, typically around 2 to 3 hours. 

Adminstartion

Administration:  

Apply a thin layer: Take a small amount of dibucaine ointment on your fingertip or a clean cotton swab. Apply it on affected area 

Avoid rubbing it in vigorously; simply spread it evenly over the skin. 

Frequency of application: It is typically applied two to three times a day, but follow the specific directions given to you. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: dibucaine topical ointment 

Why do we use dibucaine topical ointment?  

Hemorrhoids: To alleviate the pain, itching, and discomfort associated with hemorrhoids, temporary relief can be achieved by applying the ointment directly to the affected area. Its mechanism of action involves numbing the region and minimizing irritation. 

Anal fissures: The ointment may be used to alleviate the pain and discomfort associated with anal fissures.The ointment helps to numb the area and promote healing. 

Minor skin irritations: The ointment can be applied to minor cuts, scrapes, or insect bites to provide temporary relief from pain and itching. It helps numb the area and reduces discomfort. 

Pruritus ani: Pruritus ani refers to itching around the anus. Dibucaine ointment may be used to alleviate the itching and provide temporary relief.