Hormone replacement therapy preparations

McLintock LA, Dykes A, Tait RC, Walker ID. Interaction between hormone replacement therapy preparations and oral anticoagulant therapy. Br J Obstet Gynaecol 2003 110 777-9. 

Coadministration with other hormonal contraceptive preparations or hormone replacement therapy Although the effect of other hormonal contraceptive preparations or replacement therapy on the pharmacokinetics of lamotrigine has not been evaluated, the effect may be similar to oral contraceptives. Therefore, similar adjustments to the dosage of lamotrigine may be needed. 

Levothyroxine sodium (Levothwid, Synthroid, Levoxine) is the sodium salt of the naturally occurring levorota-tory isomer of T4. It is the preparation of choice for maintenance of plasma T4 and T3 concentrations for thyroid hormone replacement therapy in hypothyroid patients. It is absorbed intact from the gastrointestinal tract, and its long half-life allows for convenient once-daily administration. Since much of the T4 is deiodi-nated to T3, it is usually unnecessary to use more expensive preparations containing bothX4 and Tj.The aim is to establish euthyroidism with measured serum concentrations of T4, T3, and TSH within the normal range. 

Women with endometriosis receive treatment courses of 6 months duration. Concomitant low-dose hormone replacement therapy has been reported to diminish bone loss without significantly decreasing clinical effectiveness. Women with uterine fibroids that are symptomatic (menorrhagia, anemia, pain) receive treatment courses of 3 months, by which time women have amenorrhea or reduced menorrhagia uterine fibroids are reduced in size an average of 37%. Intramuscular depot preparations containing 3.75 mg (monthly) or 11.5 mg (every 3 months) are used. 

St John s wort 2. Red clover 3. Saw palmetto 1. Oral contraceptives Failure of contraception. Theoretically, saw palmetto could interfere with oral contraception and hormone replacement therapy St John s wort preparations induce metabolizing CYP3A4 enzymes and glycoprotein drug transporters of these medications Avoid concomitant use. Use an alternative contraceptive methods (barrier methods) if the herb is introduced... 

Ffuman and animal exposure to phytoestrogens usually occurs by two routes, ingestion of food products containing the agents or as over-the-counter nutritional supplements. Ffowever, a number of cosmetic preparations contain certain of these natural estrogens which may be absorbed through the skin. Medical problems associated with administration of hormone replacement therapy, as described in the report of the Women s Health Initiative, have motivated many women to seek nonmedical means of post-menopausal endocrine replacement, such as phytoestrogen supplements. 

Premarin is an estrogen preparation that is sometimes prescribed to women at the time of the menopause as hormone replacement therapy. The name is derived from pregnant mare s urine, the source of the hormonal preparation. 

Thyroid-stimulating hormone can be used clinically to test thyroid function but has not found practical apphcation in the treatment of human thyroid insufficiency. Direct replacement therapy with thyroid hormone is easy and effective, owing to a simple molecular stmcture. TSH has been used in the veterinary treatment of hypothyroidism, and preparations of TSH ate produced by Cooper Animal Health, Inc. and Armour Pharmaceuticals. 

Levothyroxine (L-thyroxine, T4) is the drug of choice for thyroid hormone replacement and suppressive therapy because it is chemically stable, relatively inexpensive, free of antigenicity, and has uniform potency however, any of the commercially available thyroid preparations can be used. Once a particular product is selected, therapeutic interchange is discouraged. 

The primary method of treating hypothyroidism is to administer thyroid hormones as replacement therapy. Long-term administration of thyroid hormones is usually a safe, effective means of maintaining optimal patient health in hypothyroidism. Replacement therapy using thyroid hormone preparations is described below. 

Synthetic levothyroxine is the preparation of choice for thyroid replacement and suppression therapy because of its stability, content uniformity, low cost, lack of allergenic foreign protein, easy laboratory measurement of serum levels, and long half-life (7 days), which permits once-daily administration. In addition, T4 is converted to T3 intracellularly thus, administration of T4 produces both hormones. Generic levothyroxine preparations can be used because they provide comparable... 

Pharmacologic treatment of panhypopituitarism consists of glucocorticoids, thyroid-hormone preparations, sex steroids, and recombinant growth hormone, where appropriate, as lifelong replacement therapy. 

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