darifenacin

Action and Spectrum

Actions and Spectrum: 

darifenacin is a medication that belongs to a class of drugs called antimuscarinics. It works by blocking the action of a chemical messenger in the body called acetylcholine, which helps to relax the bladder and urinary tract muscles. It can help reduce overactive bladder symptoms, such as frequent urination and urgent need to urinate. Darifenacin is typically used to treat urinary incontinence and urinary urgency. 

Drug Interaction

Adverse Reaction

>10%: 

Constipation (15-21%) 

Dry mouth (19-35%) 

1-10%: 

Dry eyes (2%) 

Dyspepsia (3-8%) 

Abdominal pain (2-4%) 

Dizziness (2%) 

Vaginitis (>1%) 

Back pain (>1 

Vomiting (>1%) 

Weight gain (>1%) 

Abnormal vision (>2%) 

Peripheral edema (>1%) 

Flu-like syndrome (1-3%) 

Black Box Warning

Black Box Warning: 

It is essential to follow the dosage and administration instructions for the medication carefully.

Contraindication / Caution

Contraindication/Caution: 

darifenacin should not be used in people hypersensitive to the drug itself. 

Pregnancy / Lactation

Pregnancy consideration:  

No data is available regarding the usage of the drug during pregnancy. 

Breastfeeding warnings:  

No data is available regarding the secretion of the drug in breast milk. 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies do not show risk to the fetus in the first/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 available 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: No data is available for the drug under this category. 

Pharmacology

Pharmacology 

darifenacin is a medication that belongs to a class of drugs called antimuscarinics. It works by blocking the action of the chemical messenger acetylcholine in the body. Specifically, darifenacin selectively blocks M3 muscarinic receptors in the bladder and urinary tract smooth muscle. It helps to relax the bladder and urinary tract muscles, which can reduce symptoms of an overactive bladder, such as frequent urination and urgent need to urinate. 

Pharmacodynamics: 

darifenacin is an antimuscarinic medication. It works by blocking the action of the chemical messenger acetylcholine in the body. Specifically, darifenacin selectively blocks M3 muscarinic receptors in the bladder and urinary tract smooth muscle. 

When acetylcholine binds to these receptors, it causes the muscles in the bladder and urinary tract to contract. By blocking this binding, darifenacin helps to relax these muscles. It reduces overactive bladder symptoms such as urinary urgency, frequency, and incontinence. 

Pharmacokinetics:  

Pharmacokinetics studies how a drug is absorbed, distributed, metabolized, and eliminated by the body. The pharmacokinetics of darifenacin can be summarized as follows: 

Absorption 

darifenacin is well absorbed after oral administration, with a bioavailability of about 70%. It can be taken with or without food but taking it with food may decrease the absorption rate. 

Distribution 

darifenacin is highly protein-bound and has a large volume of distribution. It can cross the blood-brain barrier, which allows it to reach the CNS and cause side effects such as dry mouth, constipation, blurred vision, and drowsiness. 

Metabolism 

darifenacin is metabolized in the liver by CYP3A4 enzymes. Its primary metabolite is 5-hydroxymethyl darifenacin which is pharmacologically active. 

Elimination and excretion 

darifenacin is eliminated mainly by the kidneys. The elimination half-life of darifenacin is about 20 hours, which means it takes about 20 hours for half of the drug to be eliminated from the body. 

Adminstartion

Administration: 

Do not crush or chew the tablet.  

Take one tablet at a time, with fluids or water. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: darifenacin 

Pronounced: da-ri-fen-acin 

Why do we use darifenacin? 

darifenacin is used to treat overactive bladder.