Carbamazepine is an anticonvulsant agent used primarily to prevent seizures in conditions such as epilepsy.
The herb ginkgo (Ginkgo biloba) has been used to treat Alzheimer's disease and ordinary age-related memory loss, among many other conditions.
This interaction involves potential contaminants in ginkgo, not ginkgo itself.
In light of these findings, taking a ginkgo product that happened to contain significant levels of the nerve toxin might theoretically prevent an anticonvulsant from working as well as expected.
The amino acid glutamine is converted to glutamate in the body. Glutamate is thought to act as a neurotransmitter (chemical that enables nerve transmission). Because anticonvulsants work (at least in part) by blocking glutamate pathways in the brain, high dosages of the amino acid glutamine might theoretically diminish an anticonvulsant's effect and increase the risk of seizures.
Because of this risk, if you use carbamazepine, the safest approach is to avoid grapefruit juice altogether.
Ipriflavone, a synthetic isoflavone that slows bone breakdown, is used to treat osteoporosis.
Because anticonvulsants are known to contribute to the development of osteoporosis, a concern is that the use of ipriflavone for this drug-induced osteoporosis could result in higher blood levels of the drugs with potentially serious consequences.
Individuals taking either of these drugs should use ipriflavone only under medical supervision.
The herb kava (Piper methysticum) has a sedative effect and is used for anxiety and insomnia.
Other herbs having a sedative effect that might cause problems when combined with anticonvulsants include ashwagandha(Withania somnifera) , calendula(Calendula officinalis) , catnip(Nepeta cataria) , hops(Humulus lupulus) , lady's slipper ( Cypripedium species), lemon balm(Melissa officinalis) , passionflower(Passiflora incarnata) , sassafras (Sassafras officinale) , skullcap(Scutellaria lateriflora) , valerian(Valeriana officinalis) , and yerba mansa (Anemopsis californica).
Because of the potentially serious consequences, you should avoid combining these herbs with anticonvulsants or other drugs that also have sedative or depressant effects unless advised by your physician.
Nicotinamide (also called niacinamide) is a compound produced by the body's breakdown of niacin ( vitamin B 3 ). It is a supplemental form that does not possess the flushing side effect or the cholesterol-lowering ability of niacin.
Nicotinamide appears to increase blood levels of carbamazepine and primidone, possibly requiring a reduction in drug dosage to prevent toxic effects.
St. John's wort (Hypericum perforatum) is primarily used to treat mild to moderate depression.
The herb dong quai (Angelica sinensis) is often recommended for menstrual disorders such as dysmenorrhea, PMS, and irregular menstruation.
The anticonvulsant agents carbamazepine, phenobarbital, and valproic acid have been reported to cause increased sensitivity to the sun, amplifying the risk of sunburn or skin rash. Because St. John's wort and dong quai may also cause this problem, taking them during treatment with these drugs might add to this risk.
It may be a good idea to wear a sunscreen or protective clothing during sun exposure if you take one of these herbs while using these anticonvulsants.
Anticonvulsants may deplete biotin, an essential water-soluble B vitamin, possibly by competing with it for absorption in the intestine. It is not clear, however, whether this effect is great enough to be harmful.
Biotin supplementation may be beneficial if you are on long-term anticonvulsant therapy. To avoid a potential interaction, take the supplement 2 to 3 hours apart from the drug. It has been suggested that the action of anticonvulsant drugs may be at least partly related to their effect of reducing biotin levels. For this reason, it may be desirable to take enough biotin to prevent a deficiency, but not an excessive amount.
However, the case for taking extra folate during anticonvulsant therapy is not as simple as it might seem. It is possible that folate supplementation itself might impair the effectiveness of anticonvulsant drugs, and physician supervision is necessary.
Anticonvulsant drugs may impair calcium absorption and, in this way, increase the risk of osteoporosis and other bone disorders.
A low blood level of calcium can itself trigger seizures, and this might reduce the effectiveness of anticonvulsants.
Carnitine is an amino acid that has been used for heart conditions, Alzheimer's disease, and intermittent claudication. Intermittent claudication is a possible complication of atherosclerosis, in which impaired blood circulation causes severe pain in calf muscles during walking or exercising.
Anticonvulsant drugs may interfere with the activity of vitamin D. As proper handling of calcium by the body depends on vitamin D, this may be another way that these drugs increase the risk of osteoporosis and related bone disorders. (See the previous Calcium topic.)
Individuals regularly taking anticonvulsants, especially those taking combination therapy and those with limited exposure to sunlight, may benefit from vitamin D supplementation.
Mothers who take these anticonvulsants may need vitamin K supplementation during pregnancy to prevent these conditions in their newborns.
- Reviewer: EBSCO CAM Review Board
- Review Date: 08/2013 -
- Update Date: 08/22/2013 -