St John’s wort (Hypericum perforatum), for example, can induce mania or hypomania in susceptible persons; ephedra-containing compounds (Ma-huang) have been reported to cause psychosis11; excessive use of ginseng can result in restlessness, nervousness, and insomnia or agitation; and there are reports of extrapyramidal symptoms with kava (Piper methysticum) use.12
St John’s wort has uterine-stimulating effects that may result in spontaneous abortion if taken during pregnancy. In addition, it can cause a photosensitive rash and should not be used by patients who are likely to experience prolonged sun exposure.
Kava may cause loss of uterine tone and should not be used by pregnant women. Women who are breastfeeding should also avoid using kava, because the active constituents (kava pyrones) pass into breast milk and may have sedating effects on a nursing infant. Kava may result in excessive sedation and worsening of vegetative symptoms when used by severely depressed patients, and it should be avoided in this population. Kava should not be used concurrently with sedative-hypnotics or alcohol(Drug information on alcohol), both of which may potentiate sedative and muscle relaxant effects.
Table 1 summarizes important safety issues associated with herbals that are widely used to treat or self-treat psychiatric disorders.
Nonherbal natural products
In addition to herbals, many natural supplements are used to treat or self-treat a range of mental health problems. These include the omega-3 essential fatty acids and the amino acids 5-hydroxytryptophan, l-tryptophan, SAMe, and l-theanine. All of these naturally occurring substances are generally well tolerated in adults and cause few serious adverse effects.
In contrast, there is incomplete safety information on the use of these and other supplements in young children, pregnant women, women who are breastfeeding, and patients with serious liver or kidney disease. In these cases, maximum safe doses have not been clearly established, and conservative dosing strategies should be used together with close monitoring for treatment-emergent adverse effects. Table 2 summarizes important safety concerns associated with nonherbal natural products used to treat mental health problems.
Integrative treatment regimens that involve combinations of specific herbals, other natural products, and pharmacological agents are contraindicated because of associated risks of toxicity or acute exacerbations of psychiatric disorders. Ephedra, ginseng, and guarana should be avoided in bipolar and schizophrenic patients who are taking conventional mood stabilizers or antipsychotics.13 These herbals can potentially cause insomnia, agitation, and worsening of psychosis or manic symptoms.
Commercial sale of ephedra in the United States was banned in 2003; nevertheless, it is still easy to obtain at Chinese medical pharmacies or by mail order. Mental health professionals should therefore ask patients who are being treated by a Chinese medical practitioner about the specific herbal formulas that are being used to ensure these do not contain ephedra. It is prudent to contact the prescribing Chinese medical practitioner when a patient cannot provide detailed information.
Ginseng can potentiate the effect of monoamine oxidase inhibitors, and it may result in a hypertensive crisis. Several case reports of interactions between ginseng and phenelzine(Drug information on phenelzine) have been reported. Guarana (Paullinia cupana) is a stimulant that should be avoided by bipolar and schizophrenic patients who take conventional medications because of case reports of agitation, mania, and insomnia.
Valerian may potentiate the effects of alcohol as well as the conventional sedative-hypnotics, including benzodiazepines.