evening primrose (generic name)
an herbal product - treats Cardiovascular health, Obesity/weight loss, Raynaud's phenomenon, Pre-eclampsia/high blood pressure of pregnancy, Mu...
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Interactions with Drugs
Because of reported seizures in people taking evening primrose oil alone or in combination with certain medications used to treat mental illness, patients should use caution when combining evening primrose oil with medications like chlorpromazine (Thorazine®), thioridazine (Mellaril®), trifluoperazine (Stelazine®), or fluphenazine (Prolixin®). Individuals undergoing surgery requiring general anesthesia may be more sensitive to developing seizures, and should stop taking evening primrose oil two weeks ahead of time. In people with a history of seizures, doses of anti-seizure medications may require adjustment because evening primrose oil may increase the risk of seizures.
An ingredient of evening primrose oil, gamma-linolenic acid, is reported to lower blood pressure in animal studies. Although human studies do not show clear changes in blood pressure, people taking certain blood pressure medications should consult with a healthcare professional before starting evening primrose oil.
Possible interactions may occur with antidepressants, including monoamine oxidase inhibitors (MAOIs) and selective serotonin reuptake inhibitors (SSRIs). Interactions may also occur with the following: antineoplastic agents, anti-obesity agents, antiviral agents, CNS stimulants, drugs metabolized by the liver, gastrointestinal treatments, and neurological agents.
Interactions with Herbs and Dietary Supplements
In animal studies, gamma-linolenic acid (an ingredient of evening primrose oil) is reported to lower blood pressure. Therefore, in theory, evening primrose oil may have effects on blood pressure, and should be used cautiously when combined with other agents that may lower blood pressure.
Theoretically, evening primrose oil may have additive effects when taken concomitantly with thyme, because a fixed combination of thyme fluid extract and primrose root tincture (Bronchicum Tropfen) has been used in studies to treat bronchitis.
Primrose oil may potentially interact with herbs and supplements used to treat arthritis, gastrointestinal disorders, obesity, seizures, viral infections, and psychosis. Primrose oil may interact with stimulants and herbs and supplements that are metabolized in the liver. Antineoplastics may also interact with primrose.
This information is based on a professional level monograph edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): E-P Barrette, MD (Case Western Reserve University School of Medicine); Ethan Basch, MD, MSc, MPhil (Memorial Sloan-Kettering Cancer Center); Samuel Basch, MD (Mt. Sinai Medical Center); Steve Bent, MD (University of California, San Francisco); Heather Boon, BScPhm, PhD (University of Toronto); Wendy Chao, PhD (Natural Standard Research Collaboration); Dawn Costa, BA, BS (Natural Standard Research Collaboration); Cynthia Dacey, PharmD (Northeastern University); Edzard Ernst, MD, PhD (University of Exeter); Paul Hammerness, MD (Massachusetts General Hospital); Shaina Tanguay-Colucci, BS (Natural Standard Research Collaboration); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Mamta Vora, PharmD (Northeastern University); Wendy Weissner, BA (Natural Standard Research Collaboration); Peter Wolsko, MD (Harvard Medical School).