natamycin

Action and Spectrum

Actions and Spectrum: 

Action:

natamycin exerts its antifungal action by inhibiting the growth and proliferation of various fungi, including yeast and molds. It disrupts the fungal cell membrane, explicitly targeting the ergosterol component. Ergosterol is a crucial component of the fungal cell membrane, like how cholesterol is essential for the structure and function of human cells. natamycin attaches itself to ergosterol, a key component of the fungal cell membrane. This interaction results in the formation of pores or openings in the membrane, which leads to the release of intracellular contents and, consequently, the demise of the fungal organism. 

Spectrum: 

Ocular Infections: natamycin is widely used as an ophthalmic antifungal agent to treat fungal keratitis, a severe cornea infection caused by fungi. 

Skin and Mucosal Infections: natamycin can be employed topically to treat fungal infections affecting the skin, nails, and mucous membranes, such as oral thrush (oral candidiasis) and vaginal yeast infections (vulvovaginal candidiasis). 

Drug Interaction

Adverse Reaction

Frequency not defined  

Respiratory: Dyspnea 

Ophthalmic: eye pain, corneal opacity, periorbital edema, eye irritation, hyperemia, Eye discomfort 

Nervous system: Paresthesia 

Hypersensitivity: Hypersensitivity reaction 

Cardiovascular: Chest pain 

Black Box Warning

Black Box Warning:  

None

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Individuals with a known hypersensitivity or allergic reaction to natamycin or its components should not use this medication. 

Viral Infections: natamycin is specifically designed to target and treat fungal infections. It is not effective against viral infections, such as those caused by viruses like herpes or adenovirus. Using natamycin to treat viral infections is not appropriate and may not provide any benefit. 

Use in Systemic Infections: natamycin is meant for topical use, primarily in the eye. It is not intended for treating systemic fungal infections or infections in other parts of the body. The drug’s efficacy and safety have not been established for systemic use. 

Use in Eye Trauma: natamycin should not be used in cases of eye trauma or injuries, as it is specifically indicated for fungal infections. Other appropriate treatments should be sought for traumatic eye injuries. 

Concurrent Bacterial Infections: natamycin is not effective against bacterial infections. If a patient has both bacterial and fungal infections in the eye, it is essential to differentiate between the two and provide appropriate treatment for each. 

Pregnancy and Breastfeeding: The safety of natamycin during pregnancy and breastfeeding has not been thoroughly studied The advisable approach is typically to refrain from using the medication during pregnancy unless the potential benefits outweigh the potential risks. Pregnant and breastfeeding individuals should consult their healthcare providers before using natamycin. 

Children: While natamycin is commonly used in pediatric patients, its use should be done under the supervision of a healthcare professional, especially in infants and very young children. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

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:  

natamycin is an antifungal medication used in ophthalmology and food preservation. 

Pharmacodynamics:  

natamycin works by inhibiting the growth and replication of fungi, specifically yeast and filamentous fungi. The mechanism of action involves disrupting the synthesis of ergosterol, a vital element in the formation of fungal cell membranes. Without adequate ergosterol, the integrity of the fungal cell membrane is compromised, leading to cell death and inhibition of further fungal growth.   

Pharmacokinetics: 

Absorption 

natamycin is not well absorbed through the gastrointestinal tract when taken orally. Therefore, it is primarily administered topically, such as in the form of eye drops, ointments, or creams. When applied topically, natamycin is absorbed through the affected tissues, such as the conjunctiva in the case of eye drops. 

Distribution 

After absorption through the topical route, natamycin may enter the bloodstream to some extent, but the systemic distribution is limited due to its poor oral bioavailability. It is more likely to remain localized at the site of application, such as the eyes or other mucous membranes. 

Metabolism 

natamycin is minimally metabolized in the body. The liver primarily metabolizes drugs, but natamycin’s limited systemic absorption reduces its exposure to hepatic metabolism. Instead, it likely undergoes some enzymatic breakdown at the site of application or gets excreted unchanged. 

Excretion and Elimination 

Since natamycin is minimally absorbed systemically, most of the drug is excreted unchanged. Most of it is likely eliminated from the body through the feces after passing through the gastrointestinal tract. A small portion may also be excreted via the kidneys, but this is likely a minor route of elimination. 

Adminstartion

Administration:  

Ophthalmic:  

• This medication is intended for topical ophthalmic use exclusively. Before applying, ensure proper shaking.  
• Prior to and after use, remember to wash your hands. 
•  Avoid contact between the applicator tip and your eyes or any other surfaces. 

Skin Infections (Topical use): 

• Before applying the cream, make sure the affected area is both clean and dry. 
• Apply a delicate layer of the cream onto the affected skin, and gently massage.  
• After applying the medication, remember to wash your hands, unless they are part of the affected area. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: natamycin 

Why do we use natamycin?  

Ophthalmic Use: natamycin is commonly used in the form of eye drops or ophthalmic ointments to treat fungal eye infections, specifically those caused by susceptible fungi like Candida and Aspergillus. It is effective in treating conditions such as fungal keratitis, conjunctivitis, and other ocular infections. 

Topical Use: natamycin can be used as a topical cream or ointment for superficial skin infections caused by fungi. It is effective against various dermatophytes, yeasts, and molds that can cause skin infections, such as athlete’s foot (tinea pedis), ringworm (tinea corporis), and candidiasis.