PDR for Herbal Medicines

808 /WHITE WILLOW PDR FOR HERBAL MEDICINES

Flower and Fruit: The male flowers are yellow and the

female green. They are dioecious and appear at the same

time as the leaves on leafy stems in erect catkins. The male

catkins are densely blossomed and cylindrical, up to 6.5 cm

by 1 cm and have 2 stamens. The female catkins are

cylindrical, 4.5 cm by 7 mm. The seeds have a tuft of hair.

Leaves, Stem and Root: Silver Willow is a 6 to 18 m high

tree or bush with fissured gray bark. The leaves are short-

petioled, lanceolate, acuminate and become cuneate at the

base. They are finely serrate, silky-haired tomentose under-

neath and blue-green matte.

Characteristics: The annual twigs are not easy to break off at

the base.

Habitat: The plant is indigenous to central and southern

Europe.

Production: White Willow bark consists of the bark of the

young, 2 to 3 year old branches harvested during early spring

of Salix alba, Salix purpurea, Salix fragilis and other

comparable Salix species.

Other Names: Willow, Salicin Willow, Withe Withy, Black

Willow, Cartkins Willow, Pussywillow

ACTIONS AND PHARMACOLOGY

COMPOUNDS

Glycosides and esters yielding salicylic acid (1.5-12%):

salicin (0.1-2%), salicortin (0.01-11%) and salicin deriva-

tives acylated to the glucose residue (up to 6%, including,

among others, fragilin, populin)

Tannins (8-20%)

Flavonoids

EFFECTS

The efficacy of the drug is due mainly to the proportion of

salicin present. After splitting of the acyl residue, the salicin

glycosides convert to salicin, the precursor of salicylic acid.

Salicylic acid is antipyretic, antiphlogistic and analgesic.

White Willow bark is the phytotherapeutic precursor to

acetylsalicylic acid (aspirin).

The salicin component is responsible for the anti-inflamma-

tory and antipyretic effects. The tannin content has astringent

properties on mucous membranes.

INDICATIONS AND USAGE

Approved by Commission E:

• Rheumatism


• Pain

Salicin is useful in diseases accompanied by fever, rheumatic
ailments, headaches and pain caused by inflammation.

CONTRAINDICATIONS

Willow Bark is contraindicated in patients that have a

hypersensitivity to salicylates. Salicylates should not be used

in children with flu-like symptoms due to the association of

salicylates with Reyes Syndrome.

PRECAUTIONS AND ADVERSE REACTIONS

General: No health hazards are known in conjunction with

the proper administration of designated therapeutic dosages.

Stomach complaints could occur as a side effect due to the

tannin content.

Drug Interactions: Due to the salicin component, caution

should be exercised when used in combination with salicy-

lates and other non-steroidal anti-inflammatory drugs. There

are reports that salicylate decreased serum naproxen concen-

trations markedly and increased serum naproxen clearance

by as much as 56% (Furst, 1987).

Though there are no reports of interactions with drugs that

affect blood clotting times, and some studies suggest that

thrombocyte inhibition is unlikely. Anti-platelet medications

and any medication that prolongs the PT time should not be

used with Willow Bark (Wichtl & Bisset, 1994).

Alcohol and barbiturates may mask the symptoms of

salicylate overdosage and may enhance the toxicity of

salicylates.

There have been reports of metabolic acidosis in children

with normal renal and hepatic function that were treated with

salicylates and carbonic anhydrase inhibitors for joint pain

and glaucoma. This combination should be avoided (Cowan,

1984).

Disease Interactions: Patients with an ' active gastric or

duodenal ulcer should avoid Willow Bark preparations.

Hemophiliacs or anyone with a bleeding disorder should not

use Willow Bark. Willow Bark should be avoided in

asthmatics and diabetics.

Pregnancy: Salicylates should be avoided during pregnancy.

Nursing Mothers: Salicylates have been associated with

rashes in breast-fed infants; use is not recommended.

DOSAGE

Mode of Administration: Liquid and solid preparations for

internal use. Combinations with diaphoretic drugs 'could be

considered. Drug extracts are contained in some standardized

preparations of analgesics/antirheumatics, hypnotics/seda-

tives, and gastrointestinal remedies.

Preparation: To prepare an infusion, use 2 to 3 gm of finely

cut or coarsely powdered drug in cold water, boil, allow to

steep for 5 minutes, then strain.