Nitrous oxide is an anesthetic gas. It is used during dental work and with patients who are not candidates for more commonly used anesthetics during surgery.
Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem contradictory. For clarification, read the full article for details about the summarized interactions.
 May be Beneficial: Depletion or interference—The medication may deplete or interfere with the absorption or function of the nutrient. Taking these nutrients may help replenish them. | Folic acid Vitamin B12 |
| May be Beneficial: Side effect reduction/prevention—Taking these supplements may help reduce the likelihood and/or severity of a potential side effect caused by the medication. | Catechin* Ginger* Milk thistle* |
| Supportive interaction | None known |
| Reduced drug absorption/bioavailability | None known |
| Adverse interaction | None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Dietary Supplements
Folic acid and Vitamin B12
Nitrous oxide interferes with activity of vitamin B12, which further interferes with the activity of folic acid, causing adverse actions.1 2 Administration of folic acid or folinic acid (activated folic acid) has reversed nitrous oxide-induced bone marrow changes.3 4 People with vitamin B12 deficiency may be especially susceptible.5 People who will undergo nitrous oxide anesthesia for several hours may benefit from vitamin B12 and folic acid supplementation.6 Some doctors recommend 100 mcg of vitamin B12 and 1,000 mcg folic acid, starting one week before through one week after prolonged exposure to nitrous oxide. People with normal vitamin B12 levels who undergo short-duration nitrous oxide anesthesia (less than two hours) do not require supplementation.
Catechin
Some general anesthetic drugs have infrequently caused liver damage. One animal study showed that taking catechin (a bioflavonoid) prior to halothane exposure reduced the amount of liver damage caused by the drug.7 Additional research is needed to determine whether this protective effect occurs in humans and with other general anesthetics.
Interactions with Herbs
Ginger (Zingiber officinale)
General anesthetics commonly cause nausea upon waking. In a double-blind study, taking 1 gram of ginger one hour before surgery was as effective at reducing nausea and vomiting as the anti-nausea drug metoclopramide.8 Individuals taking ginger in order to avoid side effects should disclose this to their doctor prior to surgery, since the herb might affect blood clotting.
Milk thistle (Silybum marianum)
Some general anesthetic drugs have infrequently caused liver damage. One animal study showed that taking silybine, an active compound found in milk thistle, prior to halothane exposure reduced the amount of liver damage caused by the drug.9 Though controlled research in humans is necessary, some doctors of natural medicine currently suggest taking milk thistle standardized to contain 140 mg of silymarin three times a day, beginning a week before surgery and continuing for at least one week after surgery.
References
1. Ermens AA, Refsum H, Rupreht J, et al. Monitoring cobalamin inactivation during nitrous oxide anesthesia by determination of homocysteine and folate plasma and urine. Clin Pharmacol Ther 1991;49:385–93.
2. Flippo TS, Holder WD Jr. Neurologic degeneration associated with nitrous oxide anesthesia in patients with vitamin B12 deficiency. Arch Surg 1993;128:1391–5.
3. Nunn JF, Chanarin I, Tanner AG, Owen ER. Megaloblastic bone marrow changes after repeated nitrous oxide anesthesia. Reversal with folic acid. Br J Anaesth 1986;58:1469–70.
4. Amos RJ, Amess JA, Hinds CJ, Mollin DL. Investigations into the effect of nitrous oxide anesthesia on folate metabolism in patient receiving intensive care. Chemioterapia 1985;4:393–9.
5. Koblin DD, Tomerson BW, Waldman FM, et al. Effect of nitrous oxide on folate and vitamin B12 metabolism in patients. Anesth Analg 1990;71:610–7.
6. Amos RJ, Amess JAL, Hinds CJ, Mollin DL. Incidence and pathogenesis of acute megaloblastic bone-marrow change in patients receiving intensive care. Lancet 1982;ii:835–9.
7. Siegers CP, Fruhling A, Younes M. Influence of dithiocarb, (+)-catechin and silybine on halothane hepatotoxicity in the hypoxic rat model. Acta Pharmacol Toxicol (Copenh) 1983;53:125–9.
8. Phillips S, Ruggier R, Hutchinson SE. Zingiber officinale (ginger)—an antiemetic for day case surgery. Anaesthesia 1993;48:715–7.
9. Siegers CP, Fruhling A, Younes M. Influence of dithiocarb, (+)-catechin and silybine on halothane hepatotoxicity in the hypoxic rat model. Acta Pharmacol Toxicol (Copenh) 1983;53:125–9.
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2006-09-07
