Butagest, also known as buterol, is a modification of megestrol acetate in which the C-3 ketone has been replaced by a C3β butanoyloxy moeity. It is chemically known as 3β-hydroxy-6-methyl-17α-hydroxypregna-4,6-dien-20-one 3β-butanoate 17α-acetate or 6-methyl-17α-hydroxy-δ6-progesterone 3β-butanoate 17α-acetate and is a steroidal progestin which was developed in Russia for potential clinical use as a progesterone supplement primarily for hormone replacement therapy but it was never marketed for reasons which are still unclear.
Pharmacology Butagest is a synthetic progestin that mimics the physiological actions of natural progesterone. It is used in various therapeutic contexts, including hormone replacement therapy, fertility treatments, and menstrual irregularities.
Mechanism of action Butagest acts as an agonist at progesterone receptors in various tissues. Its primary actions include:
Promoting endometrial secretory changes to support embryo implantation and pregnancy. Suppressing the hypothalamic-pituitary-gonadal axis to prevent ovulation. Modulating the immune response to maintain a pregnancy-friendly environment. By stabilizing the endometrium, it prevents abnormal uterine bleeding and aids in maintaining hormonal balance during assisted reproductive therapies.
Pharmacokinetics Absorption: Butagest is efficiently absorbed following oral or vaginal administration, with its bioavailability dependent on the route of administration. Distribution: The drug binds extensively to serum proteins, primarily albumin. Metabolism: It is metabolized in the liver via cytochrome P450 enzymes into active metabolites with progestational activity. Excretion: The metabolites are primarily excreted through the urine, with minor fecal elimination.
Adverse effects The use of butagest, which contains progesterone, is associated with several adverse effects. These vary depending on the dose, route of administration, and individual susceptibility.
Common adverse effects
Gastrointestinal Nausea Vomiting Constipation or diarrhea
Neurological Headache Dizziness Fatigue
Breasts Tenderness Swelling
Mood and behavioral Mood swings Irritability Depression or anxiety
Skin Acne Rash or itching (rare)
Reproductive Irregular menstrual bleeding Spotting
Serious adverse effects These effects require immediate medical attention:
Cardiovascular Blood clots (thromboembolism) Stroke Hypertension
Hepatic Jaundice Elevated liver enzymes
Endocrine and metabolic Weight gain Fluid retention
Neurological Severe headaches Visual disturbances (potential sign of thrombosis)
Allergic reactions Anaphylaxis (rare) Angioedema
Cancer risks Increased risk of hormone-sensitive cancers, such as breast and ovarian cancers, especially with combined hormone therapy.
Precautions Butagest should be used cautiously in patients with a history of:
Thromboembolic disorders Hormone-sensitive cancers Severe liver disease Regular monitoring is recommended for those with:
Cardiovascular risks Migraines Diabetes
Toxicology The toxicology of progesterone, the active ingredient in butagest, has been studied extensively. Below are key findings:
Acute toxicity Progesterone exhibits low acute toxicity. Overdose typically results in mild symptoms such as nausea and dizziness, without life-threatening effects.
Chronic toxicity Long-term high-dose use may increase the risk of thromboembolic disorders, cardiovascular diseases, and hormone-sensitive cancers such as breast cancer.
Carcinogenicity Progesterone is classified by the International Agency for Research on Cancer (IARC) as possibly carcinogenic to humans (Group 2B).
Environmental toxicity Improper disposal of progesterone can disrupt aquatic ecosystems, as it is an endocrine-disrupting compound.
See also Acetomepregenol Clogestone Clogestone acetate Mecigestone List of Russian drugs
References
Further reading Smith, J.A., & Brown, R.T. (2022). *Clinical Pharmacology of Progesterone Derivatives*. Journal of Reproductive Medicine, 45(3), 123–130. World Health Organization. (2023). *Guidelines on Hormonal Treatments*. Available from: [WHO Publications](https://www.who.int) National Institutes of Health. (2023). "Butagest: Drug Information." [NIH Database](https://www.nih.gov).