Progesterone vaginal ring, also known as progesterone-only vaginal ring, is a form of vaginal ring used for birth control when breastfeeding. Use can begin at four weeks and continue for at least up to a year following childbirth. Failure rates with usual use is about 1.5 per 100 women. It is used within the vagina with one ring lasting three months. The woman is able to place and remove the ring herself. It is sold under the brand names Progering among others.Side effects include vaginal discharge and pain with urination. It does not appear to be associated with serious side effects. With use menstrual periods often do not resume. It was specifically made for use with breastfeeding as it does not affect milk production. It works by gradually releasing the hormone progesterone.Progesterone vaginal rings have been approved for medical use since 1998. It is on the World Health Organizations List of Essential Medicines. As of 2014, they are available in a number of South and Central American countries. As of 2016, it is not available in the United States. It was developed by the Population Council. See also
Pharmacokinetics of progesterone § Vaginal administration


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Entacapone, sold under the brand name Comtan among others, is a medication commonly used in combination with other medications for the treatment of Parkinsons disease. Entacapone together with levodopa and carbidopa allows levodopa to have a longer effect in the brain and reduces Parkinsons disease signs and symptoms for a greater length of time than levodopa and carbidopa therapy alone.Entacapone is a selective and reversible inhibitor of the enzyme catechol-O-methyltransferase (COMT). When taken together with levodopa (L-DOPA) and carbidopa, entacapone stops catechol-O-methyltransferase from breaking down and metabolizing levodopa, resulting in an overall increase of levodopa remaining in the brain and body.Carbidopa/levodopa/entacapone (Stalevo), a medication developed by Orion Pharma and marketed by Novartis, is a single tablet formulation that contains levodopa, carbidopa, and entacapone. Medical uses
Entacapone is used in addition to levodopa and carbidopa for people with Parkinsons disease to treat the signs and symptoms of end-of-dose "wearing-off." "Wearing-off" is characterized by the re-appearance of both motor and non-motor symptoms of Parkinsons disease occurring towards the end of a previous levodopa and carbidopa dose. In clinical trials, entacapone has not been shown to slow progression or reverse Parkinsons disease.Entacapone is an orally active drug that can be taken with or without food. Pregnancy and breastfeeding
Pregnancy category C: risk is not ruled out.Although there have been animal studies that showed that entacapone was excreted into maternal rat milk, there have been no studies with human breast milk. Caution is advised for mothers taking entacapone while breastfeeding or during pregnancy.