Provera

Overview of Provera

Provera, containing medroxyprogesterone acetate, is a synthetic form of the naturally occurring female hormone progesterone. It is utilized in various treatment regimens including hormone replacement therapy, amenorrhea, and abnormal uterine bleeding due to hormonal imbalance. Provera is available by prescription and comes in tablet form in varying dosages.

Indications and Usage

Provera is indicated for the treatment of secondary amenorrhea, abnormal uterine bleeding due to hormonal imbalance without organic pathology, and endometrial hyperplasia. It’s also used as a part of hormone replacement therapy with estrogens. The specific conditions that Provera treats are related to its functioning as a progestin.

Dosing Information

The dosing of Provera varies depending on the specific condition being treated. It’s typically taken once a day for a prescribed period, which could range from a few days to several months, depending on the treatment plan. For secondary amenorrhea, dosing usually consists of 5 to 10 mg for 5 to 10 days. For abnormal uterine bleeding, 5 to 10 mg for 5 to 10 days during the second half of the menstrual cycle is common. Patients must follow the dosing schedule as directed by their physician. Missed doses should be taken as soon as remembered but not if it is close to the time for the next dose.

Pharmacological Mechanism

Medroxyprogesterone acetate, the active ingredient in Provera, functions as a progestin by binding to the progesterone receptors in target tissues. It decreases the effects of estrogen on tissues such as the endometrium of the uterus and promotes the growth of mammary tissue. Additionally, it inhibits gonadotropin production, which prevents follicular maturation and ovulation.

Administration Instructions

Provera should be taken orally with or without food, but taking it with food may minimize gastrointestinal side effects. The tablets should be swallowed whole with a glass of water and must not be chewed or broken. Consistency in the timing of the dose is recommended to maintain steady plasma levels of the medication.

Drug Interactions

The efficacy of Provera can be affected by certain drugs, including aminoglutethimide, which may decrease its bioavailability. Enzyme-inducing drugs such as phenytoin, carbamazepine, and rifampin can increase the metabolism of Provera, potentially leading to reduced efficacy. Conversely, Provera may affect the effectiveness of other drugs like cyclosporine and may interfere with laboratory tests by causing changes in certain hormone levels.

Special Populations

Caution is advised when prescribing Provera to individuals with a history of thromboembolic disorders, cardiovascular disease, renal impairment, or liver dysfunction. It should be used with caution in patients with a history of depression, diabetes, or conditions influenced by fluid retention. Pediatric and geriatric populations may require specific adjustments to dosing and close monitoring for adverse effects.

Side Effects and Adverse Reactions

Provera use may lead to side effects such as menstrual irregularities, amenorrhea, headache, weight changes, and edema. Patients may also experience nervousness, dizziness, skin rash, acne, or hair growth/loss. Serious adverse reactions, while less common, can include thrombotic events, ocular disturbances, or dyspnea. Monitoring is necessary to detect and manage these effects promptly.

Overdose Management

Although no specific antidote is available for overdosage with Provera, symptoms can be treated symptomatically. In the event of an acute overdose, gastric lavage or induced emesis can be considered if undertaken soon after ingestion. As Provera is a hormonally active agent, prolonged use of high doses could lead to serious hormonal disturbances.

Pharmacokinetics Profile

Medroxyprogesterone acetate is absorbed from the gastrointestinal tract with peak plasma concentrations occurring within 2 to 4 hours after oral administration. Its elimination half-life ranges from 25 to 50 hours. The drug is metabolized in the liver by hydroxylation and conjugation and is excreted mainly in urine with a small proportion eliminated in feces.

Storage and Handling

Provera tablets should be stored at room temperature, away from moisture and heat. They should be kept in a closed container, out of reach of children and pets to avoid unintended ingestion. Prescription labels must be read carefully to ensure proper storage and tracking of the medication’s expiration date.

Pregnancy and Lactation

Provera should not be used during pregnancy as it may lead to adverse effects on the fetus, including genital abnormalities in a female baby. Women of childbearing potential must be evaluated for pregnancy before administration. In lactation, caution is advised since Provera is excreted in milk, and the effects on the breastfeeding infant should be considered by a healthcare provider.

Patient Counseling Information

Patients receiving Provera should be counseled on the importance of adhering to prescribed dosing schedules. They should be informed about possible side effects and advised to contact their healthcare provider if severe reactions occur. The potential for drug interactions should be discussed, as well as the importance of informing their physician of all medications they are currently taking, including over-the-counter drugs and herbal supplements.