Lemon Verbena

Aloysia citrodora

Common & Folk Names

• Lemon Beebrush
• Herb Louisa
• Cedrón
• Verveine Citronnelle
• Hierba Luisa
• Limonetto

Plant Family

Verbenaceae

Geographic Location

Native to South America, particularly Argentina, Chile, Peru, and Uruguay. Now cultivated widely in warm temperate and subtropical regions worldwide, including the Mediterranean (particularly southern France, Spain, and Italy), North Africa, southern United States, Australia, and other regions with suitable climates. Thrives in areas with warm summers and mild winters.

Habitat

Naturally grows in sunny locations with well-draining soil in its native South American range. Prefers warm, sheltered positions with protection from harsh winds. In cultivation, thrives in full sun with good air circulation. Tolerates a range of soil types but performs best in moderately fertile, well-draining soil.

Growing Conditions

Sun: Full sun; requires at least 6-8 hours of direct sunlight daily for optimal growth and essential oil production

Soil: Well-draining, moderately fertile soil; tolerates a range of soil types including sandy, loamy, or clay soils if drainage is adequate; pH 6.0-8.0; sensitive to waterlogging

Propagation: Take softwood or semi-hardwood cuttings in spring or summer (success rate is high); layering is also effective; seed propagation is possible but slow and less reliable

Care: Water regularly during establishment and dry periods but avoid overwatering; prune in spring to encourage bushy growth and remove dead wood; protect from frost (frost-tender); mulch roots in borderline hardiness zones; generally pest and disease-free; may lose leaves in cold weather

NZ Planting Calendar

Sowing (seed): Spring (September-November) after frost danger has passed; germination can be slow and erratic

Propagation (cuttings/division): Take softwood cuttings in spring (October-November) or semi-hardwood cuttings in summer (December-February); very successful propagation method

Planting: Spring (October-November) after frost risk has passed; can also plant in early autumn (March) in warmer regions

Growth: Frost-tender deciduous shrub; may be semi-evergreen in frost-free areas; can reach 2-3 metres in ideal conditions; loses leaves in winter in cooler climates

Flowering: Summer (December-February) with small white or pale lavender flowers in terminal spikes

Harvest: Leaves harvested throughout growing season (November-April); best harvested just before flowering for maximum essential oil content; can harvest multiple times per season

Note: Not native to NZ; grows well in warmer regions (Northland, Auckland, Bay of Plenty, coastal areas) and can survive in cooler areas with frost protection; may die back to ground in heavy frosts but often re-sprouts from roots; suited to container growing in colder regions (bring indoors or into greenhouse during winter); thrives in sheltered, sunny positions throughout NZ

Harvesting Guidelines

Harvest leaves throughout the growing season, with peak essential oil content occurring just before flowering. For optimal flavour and medicinal properties, harvest in the morning after dew has dried but before the heat of the day. Select healthy, unblemished leaves from throughout the plant, taking care not to remove more than one-third of the plant’s foliage at any one time to allow for recovery and continued growth. Fresh leaves have the strongest lemon scent and flavour, making them ideal for immediate use in teas, cooking, or fresh preparations. For drying, harvest larger amounts when the plant is at peak growth. Dry leaves quickly in a warm, well-ventilated area out of direct sunlight at temperatures not exceeding 35°C to preserve the volatile essential oils. Properly dried leaves should retain good green colour and strong lemon scent. Store dried leaves in airtight containers away from light and heat; they will maintain potency for 6-12 months. The plant can be harvested multiple times throughout the growing season, encouraging bushier, more productive growth.

Parts Used

• Leaves (primary medicinal and culinary part)
• Occasionally flowering tops (contain similar properties to leaves)

Constituents & their Actions

Lemon verbena’s therapeutic properties and characteristic lemon scent arise primarily from its essential oil content, along with flavonoids, phenolic acids, and other compounds that provide digestive, relaxant, and antioxidant effects.

Essential Oil (Volatile Oil):

Comprising 0.1-1% of the leaf material, the essential oil contains the compounds responsible for lemon verbena’s distinctive aroma and many of its therapeutic properties. Some of the main essential oil components in lemon verbena are:

• Citral (geranial and neral – primary lemon scent compounds)
• Limonene
• 1,8-Cineole
• Geraniol
• Linalool

The main actions of these essential oils are:

• Provide carminative effects, relieving digestive gas and bloating
• Exhibit mild sedative and anxiolytic properties
• Demonstrate antimicrobial activity against bacteria and fungi
• Contribute to antispasmodic effects on smooth muscle
• Provide the characteristic lemon aroma and flavour

Flavonoids and Phenolic Compounds:

Plant pigments and aromatic compounds with antioxidant and various physiological effects. Some of the main flavonoids in lemon verbena are:

• Apigenin
• Luteolin
• Hispidulin
• Eupafolin
• Verbascoside (acteoside)

The main actions of these flavonoids are:

• Provide potent antioxidant protection
• Exhibit anti-inflammatory effects
• Support cardiovascular health
• Demonstrate neuroprotective properties
• Contribute to digestive soothing effects

Phenolic Acids:

Including various caffeic acid derivatives and other phenolic compounds.

The main actions of these phenolic acids are:

• Provide antioxidant effects
• Support anti-inflammatory actions
• Exhibit antimicrobial properties
• Contribute to overall therapeutic profile

Iridoid Glycosides:

Complex compounds with various physiological effects. Some of the main iridoids in lemon verbena are:

• Verbenalin
• Hastatoside

The main actions of these iridoids are:

• Contribute to anti-inflammatory effects
• May provide mild sedative properties
• Support digestive function
• Work synergistically with other constituents

Actions with Mechanisms

Digestive Aid and Carminative:
The essential oils, particularly citral and limonene, relax the smooth muscle of the digestive tract and help expel gas, which in turn relieves bloating, cramping, and digestive discomfort. The aromatic compounds stimulate digestive secretions including saliva, gastric juices, and bile, improving overall digestive function and nutrient assimilation. The antispasmodic effects reduce intestinal cramping and griping. These combined actions make lemon verbena valuable for indigestion, flatulence, colic, and general digestive upset. The pleasant lemon flavour also stimulates appetite and makes the herb enjoyable to take, which supports compliance in digestive treatments.

Mild Sedative and Nervine:
Multiple constituents work together to provide gentle calming effects on the nervous system. The essential oils, particularly citral, linalool, and geraniol, produce mild sedative effects that reduce nervous tension and promote relaxation, which in turn helps calm racing thoughts and ease stress-related symptoms. Flavonoids may interact with GABA receptors or other neurotransmitter systems, contributing additional anxiolytic effects. The aromatic properties provide aromatherapeutic benefits, with the lemon scent creating positive psychological associations and mood enhancement. Unlike stronger sedatives, lemon verbena’s effects are gentle and suitable for daytime use, reducing tension without causing drowsiness in most individuals.

Antispasmodic:
The essential oils and other constituents relax smooth muscle tissue throughout the body through effects on calcium channels and neural stimulation, which in turn reduces spasms and cramping. This antispasmodic action extends to the digestive tract (relieving intestinal cramping), uterus (easing menstrual cramps), and potentially respiratory smooth muscle. The gentle, pleasant nature of lemon verbena makes it particularly suitable for stress-related spasms where stronger antispasmodics might be too sedating or have unwanted side effects.

Antioxidant:
Flavonoids, particularly verbascoside, and phenolic compounds provide potent antioxidant protection. These constituents scavenge free radicals and reactive oxygen species, which in turn protects cellular structures including lipids, proteins, and DNA from oxidative damage. Research demonstrates that lemon verbena extract exhibits significant antioxidant activity in various laboratory models, with effects comparable to or exceeding some synthetic antioxidants. The antioxidant properties support cardiovascular health, may slow aspects of ageing, and protect against oxidative stress-related diseases. The neuroprotective effects of the antioxidants may also support cognitive function and protect against neurodegenerative processes.

Anti-inflammatory:
Flavonoids and other compounds reduce inflammation through multiple mechanisms. These constituents inhibit the production of pro-inflammatory mediators including prostaglandins and cytokines, which in turn decreases inflammation throughout the body. Research shows anti-inflammatory effects in various models of inflammation. The gentle anti-inflammatory action supports lemon verbena’s use for inflammatory digestive conditions, arthritis (when used as part of a comprehensive approach), and general inflammatory states. The combination of anti-inflammatory and antioxidant effects provides protection against chronic low-grade inflammation that underlies many disease processes.

Antimicrobial:
The essential oils, particularly citral, demonstrate antimicrobial activity against various bacteria and fungi. These compounds disrupt microbial cell membranes and interfere with cellular metabolism, which in turn inhibits microbial growth. Research demonstrates activity against common foodborne bacteria, oral pathogens, and some fungi. The antimicrobial properties support lemon verbena’s traditional use for digestive infections and its modern use as a food preservative and in natural antimicrobial products. The pleasant aroma makes it more acceptable than some stronger antimicrobial herbs.

Mild Diaphoretic and Febrifuge:
Lemon verbena promotes gentle sweating and may help reduce fever through its warming essential oils and other constituents. The diaphoretic action supports detoxification and cooling of the body during feverish conditions, which in turn helps the body manage mild fevers and supports immune function during acute infections. The pleasant taste makes it suitable for feverish patients who may be reluctant to take stronger, more bitter herbs.

Aromatic and Mood-Enhancing:
The characteristic lemon scent provides aromatherapeutic benefits beyond direct pharmacological effects. The pleasant aroma creates positive psychological associations, reduces stress perception, and enhances mood through olfactory pathways connecting to emotional centres in the brain. This makes lemon verbena valuable for stress-related conditions, mild depression (particularly when related to stress), and situations where a pleasant, uplifting herb is needed to improve compliance and enjoyment of treatment.

Main Use

Lemon verbena serves as a delightful digestive aid and gentle nervine, valued as much for its exquisite lemon flavour as for its therapeutic properties. The herb excels at addressing stress-related digestive complaints, where nervous tension contributes to indigestion, gas, bloating, and intestinal cramping. The combination of carminative, antispasmodic, and nervine properties addresses both the physical digestive symptoms and the underlying nervous tension. The pleasant taste makes it particularly suitable for individuals who find more bitter digestive herbs unpalatable.

As a gentle nervine, lemon verbena provides relaxation and stress relief without significant sedation, making it suitable for daytime use. The herb helps calm nervous tension, reduce mild anxiety, ease stress-related symptoms, and promote a sense of well-being. The aromatic properties contribute to mood enhancement and emotional balance. Lemon verbena works particularly well for individuals who respond favourably to aromatic herbs and who prefer gentle, pleasant remedies over stronger, more medicinal-tasting alternatives.

For sleep support, lemon verbena can be taken before bed to promote relaxation and ease the transition to sleep, particularly when stress or nervous tension interferes with rest. The effects are gentle rather than strongly sedative, making it suitable for those who need relaxation without heavy sedation.

The herb provides gentle fever support during colds and flu, promoting sweating whilst providing pleasant hydration through its use as a tea. The antimicrobial properties may offer additional benefits during infections, whilst the pleasant taste encourages adequate fluid intake during illness.

In culinary applications, lemon verbena adds delightful lemon flavour to teas, desserts, beverages, and various dishes. The culinary use provides gentle therapeutic benefits whilst enhancing food and drink. The herb is particularly popular in herbal tea blends, where it adds flavour whilst contributing digestive and relaxation benefits.

Lemon verbena represents an excellent example of a herb that bridges the gap between food and medicine, providing genuine therapeutic benefits in a form that people genuinely enjoy consuming. This makes it valuable for individuals who are reluctant to take medicinal herbs or who prefer gentle, pleasant remedies.

Preparations

Infusion (Tea): Steep 1-2 teaspoons (1-3g) of fresh or dried leaves in 250ml freshly boiled water for 5-10 minutes; strain and drink. This is the most popular preparation, enjoyed both for therapeutic benefits and as a delicious beverage. Can be drunk hot or chilled.

Cold Infusion: Place fresh or dried leaves in cold water and refrigerate for several hours or overnight; strain and drink chilled. This method preserves more volatile compounds and creates a refreshing summer beverage with gentle therapeutic effects.

Tincture (1:5, 25-40% alcohol): Standard preparation using dried leaves; lower alcohol content is sufficient as many constituents are water-soluble. Less commonly used than tea but provides convenient dosing.

Infused Honey: Layer fresh leaves with honey and leave for 2-4 weeks; strain out leaves. The honey becomes infused with lemon verbena’s flavour and therapeutic properties. Delicious in tea or taken by the spoonful.

Tea Blend: Combine lemon verbena with complementary herbs such as chamomile, lavender, mint, or lemon balm for enhanced effects and varied flavours. The pleasant lemon taste improves the palatability of less tasty herbs.

Culinary Uses: Fresh or dried leaves added to desserts, beverages, sauces, and various dishes. Infuse in milk or cream for custards and ice cream. Add to sugar for lemon-flavoured sugar. Use in cocktails and mocktails.

Infused Oil (for aromatherapy): Fresh leaves infused in a carrier oil can be used for massage or in bath products for aromatherapeutic benefits.

Dosage

Fresh or Dried Leaf (infusion): 1-3g (approximately 1-2 teaspoons), steeped in 250ml water; drink 2-3 cups daily

Tincture (1:5, 25-40% alcohol): 2-4ml (40-80 drops), 2-3 times daily

Infused Honey: 1-2 teaspoons as needed, up to 3-4 times daily

Culinary/Beverage Use: Use freely as desired for flavour and gentle therapeutic effects

Note: Lemon verbena is gentle and safe for regular use. The pleasant taste encourages frequent consumption, which supports consistent therapeutic effects.

Safety & Drug Interactions

Scientific Evidence

Antioxidant Activity: Multiple studies demonstrate significant antioxidant activity of lemon verbena extracts. Research shows free radical scavenging activity comparable to or exceeding synthetic antioxidants in various models. The antioxidant effects are attributed primarily to verbascoside and other phenolic compounds. Studies suggest potential benefits for reducing oxidative stress and protecting against oxidative damage.

Anti-inflammatory Effects: Laboratory studies show anti-inflammatory activity through inhibition of inflammatory mediators. Research demonstrates reduced production of pro-inflammatory cytokines and other inflammatory markers. Animal studies support anti-inflammatory effects in various models of inflammation.

Weight Management and Metabolic Effects: Some research suggests lemon verbena extract may support weight management and improve metabolic markers. Studies show potential benefits for reducing oxidative stress associated with obesity, improving joint discomfort in overweight individuals, and supporting healthy metabolism. The mechanisms may involve antioxidant and anti-inflammatory effects. More research is needed to fully establish these effects.

Sleep Quality: Limited research suggests lemon verbena may improve sleep quality when combined with other herbs. A study using a combination of lemon verbena and omega-3 fatty acids showed improvements in sleep quality and stress markers. The gentle sedative effects support traditional use for sleep, though more specific research is needed.

Antimicrobial Activity: Laboratory studies confirm antimicrobial effects against various bacteria and fungi. The essential oil shows particular activity against foodborne bacteria and oral pathogens. Research supports traditional use and modern applications in food preservation.

Digestive Effects: While specific clinical research on digestive effects is limited, traditional use is extensive and the mechanisms (essential oil effects, antispasmodic properties) are well-understood from related plants. The aromatic bitter properties and carminative effects are consistent with traditional digestive applications.

Western Energetics

Temperature: Cooling to neutral. Lemon verbena’s cooling nature is evident in its use for fevers and its refreshing quality. The herb provides gentle cooling without being strongly refrigerant, making it suitable for most constitutional types. The lemon character contributes to the cooling quality.

Moisture: Slightly drying to neutral. The aromatic nature and mild diaphoretic effects provide gentle drying properties, though these are not pronounced. The herb is suitable for most tissue moisture states.

Tissue State: Particularly indicated for tension and constriction, especially when nervousness or stress contributes to physical tension. The antispasmodic and nervine properties address cramping, tightness, and stress-related holding patterns. Also valuable for excitation and heat when a cooling, calming influence is needed. The pleasant, aromatic nature makes it suitable for various tissue states where a gentle, uplifting herb is indicated.

Taste

Lemony/Citrus: The dominant taste is intensely lemony, arising from the high citral content in the essential oil. This characteristic lemon flavour is clean, bright, and refreshing, making lemon verbena one of the most pleasant medicinal herbs. The citrus quality contributes to digestive stimulation and mood enhancement.

Slightly Sweet: An underlying sweetness balances the citrus notes and contributes to the herb’s pleasant, refreshing character. This subtle sweetness makes lemon verbena more palatable than many medicinal herbs.

Aromatic: The intense aroma contributes to the overall sensory experience and therapeutic effects. The aromatic quality stimulates digestive secretions and provides aromatherapeutic benefits.

Slightly Astringent: A very mild astringent quality is present, contributing to the herb’s refreshing character without being puckering or unpleasant.

Plant Lore

Lemon verbena was brought to Europe from South America by Spanish explorers in the 17th century and quickly became popular in Spanish and French gardens. The French name “verveine citronnelle” and the Spanish “hierba luisa” (herb of Louise/Luisa) reflect its adoption and popularity in these cultures. Some sources suggest it was named after Maria Luisa, Princess of Parma, though this attribution is uncertain.

In its native South America, indigenous peoples used lemon verbena (cedrón) for digestive complaints, fevers, and nervous conditions. The herb was valued both medicinally and for its delightful aroma. Spanish colonizers adopted the plant enthusiastically and brought it back to Europe, where it became a favourite in monastery and physic gardens.

By the 18th and 19th centuries, lemon verbena was cultivated throughout the Mediterranean region, particularly in southern France, where it became an important commercial crop for the perfume industry. The essential oil was used in perfumes, soaps, and various scented products. The dried leaves were used in potpourris, sachets, and as a fragrant addition to linens.

In Victorian England, lemon verbena became fashionable in ornamental gardens and was valued for its scent. Ladies would carry small sachets of dried lemon verbena leaves or tuck fresh leaves into their clothing for the pleasant aroma. The herb appeared in many Victorian herbal and household guides.

Lemon verbena has been associated with purification and protection in various folk traditions. The clean, lemony scent was thought to cleanse spaces and ward off negative energies. In some traditions, the herb was used in cleansing baths and spiritual purification rituals.

The plant’s introduction to European and North American gardens created a new appreciation for aromatic South American plants. Lemon verbena became one of several South American herbs (along with nasturtium, Chilean guava, and others) that enriched European herbal medicine and horticulture.

In traditional South American folk medicine, lemon verbena (cedrón) was particularly valued for digestive complaints and fevers. The herb was made into teas, bath preparations, and various remedies. The tradition of drinking cedrón tea for digestion and relaxation continues in Argentina, Chile, and other South American countries.

The plant’s deciduous habit (unusual for a member of the Verbenaceae family from subtropical regions) and its frost-tenderness have made cultivation challenging in temperate climates. However, the exquisite flavour and aroma have ensured its continued popularity despite these challenges.

Additional Information

Lemon verbena is one of the most intensely lemon-scented plants, with a flavour and aroma that many consider superior to lemon itself for certain applications. The clean, true lemon scent without bitterness or sharpness makes it ideal for culinary uses where lemon flavour is desired without acidity.

Growing lemon verbena provides both ornamental value and practical benefits. The plant’s attractive form, aromatic foliage, and delicate flowers make it a lovely addition to herb gardens, containers, and ornamental landscapes. The ability to harvest leaves throughout the growing season provides continuous access to fresh herb.

In colder climates, container cultivation allows the plant to be moved indoors or into a greenhouse during winter. The plant will lose leaves and go dormant in cold conditions but will resprout from roots in spring if protected from severe frost. Some gardeners treat it as an annual in very cold climates, though the plant’s value makes preservation worthwhile.

When harvesting lemon verbena, regular pruning encourages bushier, more productive growth. The plant responds well to cutting and will produce fresh foliage throughout the growing season when harvested appropriately.

Lemon verbena combines beautifully with many other herbs:

• Lemon Verbena + Chamomile for digestive upset and relaxation
• Lemon Verbena + Mint for refreshing digestive support
• Lemon Verbena + Lavender for stress relief and sleep support
• Lemon Verbena + Rose for a delightful, mood-enhancing tea
• Lemon Verbena + Ginger for digestive support with warming properties

The dried leaves lose some intensity compared to fresh but retain good flavour for 6-12 months when properly stored. Freeze-drying preserves flavour better than air-drying, though air-drying is more accessible for home herbalists.

Essential oil of lemon verbena is available commercially but is expensive due to the low oil content of the plant. The oil is used in high-end perfumery, aromatherapy, and flavouring. However, for most purposes, the whole herb (fresh or dried) provides excellent effects and is more economical.

When purchasing dried lemon verbena, quality varies significantly. High-quality dried leaves should retain good green colour and strong lemon scent. Avoid leaves that appear brown, smell musty, or have lost their characteristic aroma, as these indicate age or poor storage.

Lemon verbena represents an excellent herb for beginning herbalists and for introducing people to herbal medicine. The pleasant taste and gentle effects provide a positive introduction to herbs, whilst the genuine therapeutic benefits demonstrate that effective medicine doesn’t need to taste unpleasant. The herb helps dispel the notion that “medicine must taste bad to work.”

The aromatic properties make lemon verbena valuable beyond internal use. The leaves can be used in bath preparations, sachets, potpourris, and various cosmetic applications. The scent provides aromatherapeutic benefits whilst the herb adds value to natural body care products.

Sources

Bone, K., & Mills, S. (2013). Principles and Practice of Phytotherapy: Modern Herbal Medicine (2nd ed.). Churchill Livingstone.

Hoffman, D. (2003). Medical Herbalism: The Science and Practice of Herbal Medicine. Healing Arts Press.

Grieve, M. (1931). A Modern Herbal. Dover Publications (1971 reprint).

Funes, L., Fernández-Arroyo, S., Laporta, O., Pons, A., Roche, E., Segura-Carretero, A., Fernández-Gutiérrez, A., & Micol, V. (2009). Correlation between plasma antioxidant capacity and verbascoside levels in rats after oral administration of lemon verbena extract. Food Chemistry, 117(4), 589-598.

Arredondo, F., Echeverry, C., Abin-Carriquiry, J. A., Blasina, F., Antúnez, K., Jones, D. P., Go, Y. M., Liang, Y. L., & Dajas, F. (2010). After cellular internalization, quercetin causes Nrf2 nuclear translocation, increases glutathione levels, and prevents neuronal death against an oxidative insult. Free Radical Biology and Medicine, 49(5), 738-747.

Quirantes-Piné, R., Funes, L., Micol, V., Segura-Carretero, A., & Fernández-Gutiérrez, A. (2009). High-performance liquid chromatography with diode array detection coupled to electrospray time-of-flight and ion-trap tandem mass spectrometry to identify phenolic compounds from a lemon verbena extract. Journal of Chromatography A, 1216(28), 5391-5397.

Akaberi, M., Mehri, S., Berenjian, A., & Hosseinzadeh, H. (2015). The genus Aloysia: A review of phytochemistry and pharmacology. Phytotherapy Research, 29(8), 1097-1109.

Carnat, A., Carnat, A. P., Fraisse, D., & Lamaison, J. L. (1999). The aromatic and polyphenolic composition of lemon verbena tea. Fitoterapia, 70(1), 44-49.

Ranilla, L. G., Apostolidis, E., Genovese, M. I., Lajolo, F. M., & Shetty, K. (2012). Evaluation of indigenous grains from the Peruvian Andean region for antidiabetes and antihypertension potential using in vitro methods. Journal of Medicinal Food, 15(3), 278-291.

Valentão, P., Fernandes, E., Carvalho, F., Andrade, P. B., Seabra, R. M., & Bastos, M. L. (2002). Antioxidative properties of cardoon (Cynara cardunculus L.) infusion against superoxide radical, hydroxyl radical, and hypochlorous acid. Journal of Agricultural and Food Chemistry, 50(17), 4989-4993.

Lenoir, L., Rossary, A., Joubert-Zakeyh, J., Vergnaud-Gauduchon, J., Farges, M. C., Fraisse, D., Texier, O., Lamaison, J. L., Vasson, M. P., & Felgines, C. (2011). Lemon verbena infusion consumption attenuates oxidative stress in dextran sulfate sodium-induced colitis in the rat. Digestive Diseases and Sciences, 56(12), 3534-3545.

Peiró, G., Funes, L., Salinas, S., Caturla, N., Tur, J., Micol, V., Herranz-López, M., Roche, E., & Barrajón-Catalán, E. (2014). Aloysia citrodora improves sleep quality and reduces oxidative stress markers in overweight subjects. Planta Medica, 80(16), P1L52.

Citores, M. J., García-Pérez, B. E., Frias, L., Cuellar, M. J., Pascual-Teresa, B., Bellido, I., & Reguero, M. T. (2008). Inhibition of stress induced gastric ulcers by verbenalin, a natural iridoid, in rats. Planta Medica, 74(09), PA347.

Weston, C. F. M. (1987). Lemon verbena tea and thyrotoxicosis. The Lancet, 330(8570), 1243. [Note: This is a single case report suggesting possible interaction; relationship is not established]

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