Herb-Drug Interactions: Shatavari

2011

Asparagus racemosus Willd. (Asparagaceae)

Synonym(s) and related species

Wild asparagus. Not to be confused with asparagus, which is Asparagus officinalis, the species used as a food.

Constituents

The root and rhizome of shatavari contain a series of steroidal saponins, the shatavarins and others, based on sarsapogenin, diosgenin and arasapogenin. The polycyclic alkaloid asparagamine A, benzofurans such as racemofuran and racemosol, and the isoflavone 8-methoxy-5,6,4′-trihydroxyisoflavone 7-O-beta-D-glucopyranoside are also present.

Use and indications

Shatavari is widely used in Ayurvedic medicine for dealing with problems related to women’s fertility, loss of libido, threatened miscarriage and menopausal problems, and to increase the flow of breast milk. It is also reported to be antispasmodic, aphrodisiac, demulcent, diuretic, anti-diar-rhoeal, antirheumatic and antidiabetic. Some of these indications are supported by pharmacological (but little clinical) evidence.

Pharmacokinetics

No relevant pharmacokinetic data found.

Interactions overview

Shatavari may have additive effects with conventional antidiabetic drugs, and may alter the absorption of a number of drugs by delaying gastric emptying. Shatavari contains phytoestrogens and therefore has the potential to be antagonistic or synergistic with oestrogens or oestrogen antagonists.

Shatavari + Antidiabetics

The interaction between shatavari and antidiabetics is based on experimental evidence only.

Evidence, mechanism, importance and management

In pharmacological studies, shatavari extracts have been shown to lower blood-glucose and stimulate insulin secretion. In one in vitro study, the insulin stimulatory effect of various extracts and partition fractions of shatavari was potentiated by tolbutamide. This suggests that shatavari might have some antidiabetic effects; this is in line with one of its traditional uses as an antidiabetic. The evidence is too slim to say whether a clinically important effect is likely for usual preparations of the herb, but an additive antidiabetic effect with conventional medicines for diabetes seems possible. Bear this information in mind in the event of an unexpected response to treatment.

Shatavari + Food

No interactions found.

Shatavari + Herbal medicines

No interactions found.

Shatavari + Miscellaneous

Limited evidence suggests that shatavari increases the gastric emptying rate similarly to metoclopramide, which is known to decrease the absorption of atovaquone, digoxin and ketoprofen, and increase the absorption of ciclosporin, dantrolene, morphine and paracetamol (acetaminophen). Shatavari has the potential to interact similarly.

Evidence, mechanism, importance and management

In a crossover study in 8 healthy subjects, powdered root of shatavari 2g reduced the gastric emptying half-life from a mean baseline of about 160 minutes to 101 minutes after two radio-labelled jam sandwiches were eaten. This was similar to the effect of a single 10-mg dose of oral metoclopramide (85 minutes). If shatavari increases the gastric emptying rate, it has the potential to increase or decrease the absorption of other drugs that are taken concurrently. Metoclopramide is known to have this effect and modestly decreases the absorption of atovaquone, digoxin and ketoprofen, and increases the absorption of ciclosporin, dantrolene, morphine and paracetamol (acetaminophen). Based on the limited evidence presented, it is possible that shatavari might interact similarly. Until more is known, some caution might be appropriate; however, note that, with the exception of atovaquone, in most cases the interactions of metoclopramide with these drugs are of limited clinical importance.

Shatavari + Oestrogens or Oestrogen antagonists

The interaction between shatavari and oestrogens or oestrogen antagonists is based on a prediction only.

Evidence, mechanism, importance and management

Shatavari contains phytoestrogens and has been investigated in a variety of pharmacological and clinical studies for its effect on lactation, dysfunctional uterine bleeding, premenstrual syndrome and menopausal symptoms; this has been the subject of a review.Based on these studies, a cautious approach would be to recommend care when combining shatavari with conventional oestrogenic drugs or oestrogen antagonists such as tamoxifen, because it is unknown whether the effects might be antagonistic or synergistic (or, indeed, not clinically relevant). For further discussion of this subject, see Isoflavones + Tamoxifen.