allylestrenol

Action and Spectrum

Actions and Spectrum: 

Action: 

Progestational Activity: Due to its progestational activity, allylestrenol mimics the actions of progesterone, a hormone found naturally in the body. An essential hormone in the female reproductive system, progesterone helps maintain pregnancy, controls the menstrual cycle, and prepares the uterine lining for the implantation of a fertilized egg. In situations where progesterone is lacking, allylestrenol can be given as a supplement. 

Spectrum: 

allylestrenol is primarily used in obstetrics and gynecology, and its spectrum of use is relatively narrow compared to other hormones. 

It is most used during pregnancy to prevent miscarriage in cases of threatened miscarriage, recurrent pregnancy loss, or when there is a history of premature birth. It is not typically used as a contraceptive. 

Drug Interaction

Adverse Reaction

Frequency not defined  

fatigue 

Headache  

Muscle pain 

Depression 

Irritation 

Anxiety 

Bloating 

Edema 

Black Box Warning

Black Box Warning:  

None

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Patients with known hypersensitivity or allergy to allylestrenol or any of its components should not use the medication. 

Thromboembolic disorders: allylestrenol should be avoided in individuals with a history of thromboembolic disorders, such as deep vein thrombosis (DVT) or pulmonary embolism since it could potentially elevate the chances of developing blood clots. 

Severe liver disease: Patients having impaired liver function should not use allylestrenol, as it is metabolized in the liver, and its safety and effectiveness in this population have not been established. 

Vaginal bleeding of unknown origin: If a woman experiences vaginal bleeding during pregnancy, the cause should be determined before considering allylestrenol, as it may mask underlying conditions that require different treatments. 

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. 

<b>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: allylestrenol is a synthetic progestin, also known as a 19-nortestosterone derivative. 

Pharmacodynamics:  

Progestational Activity: allylestrenol exerts progestational effects by binding to and activating progesterone receptors in the body. This leads to various physiological changes, including thickening of cervical mucus, inhibition of ovulation, and alteration of the endometrium to create a more receptive environment for implantation of a fertilized egg. 

Endometrial Support: allylestrenol is often prescribed to women who have a history of recurrent miscarriages or threatened miscarriage. It helps maintain the endometrial lining, ensuring adequate support for a developing embryo.  

Pharmacokinetics: 

allylestrenol is typically administered orally in the form of tablets or capsules. 

It is well absorbed from the gastrointestinal tract. 

Distribution 

allylestrenol is distributed throughout the body. 

It binds to serum proteins, primarily albumin. 

Metabolism 

allylestrenol undergoes extensive metabolism in the liver. The exact metabolic pathways may vary, but typically it is metabolized by oxidation and conjugation reactions. 

Excretion and Elimination 

The metabolites of allylestrenol and the drug itself are primarily excreted in the urine. 

The elimination half-life of allylestrenol can vary among individuals, but it is typically relatively short, ranging from several hours to a day. 

Adminstartion

Administration:  

allylestrenol is available in various forms, including tablets and capsules. It is usually taken orally, with or without food, as directed by the healthcare professional. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: allylestrenol 

Why do we use allylestrenol?  

allylestrenol is often prescribed to pregnant individuals who are at risk of miscarriage due to factors such as uterine contractions or cervical insufficiency. It can help reduce the likelihood of miscarriage and promote a successful pregnancy. 

In cases where preterm labor is a concern, allylestrenol may be used to inhibit uterine contractions and delay the onset of labor. This helps provide more time for the fetus to develop and improve its chances of survival if born prematurely.