L Arginine Treatments

L-arginine, a dietary supplement available over the counter, is an amino acid used by the body as a chemical building block to produce nitric oxide. Nitric oxide opens blood vessels wider, enhancing circulation, and stimulates the release of insulin, growth hormone and other substances in the body. Many scientific studies of the effects of L-arginine have been done and are continuing. Evidence of L-arginine's effectiveness in treating different conditions has varied.

Cardiovascular Disease

• Adding L-arginine to conventional treatment for congestive heart failure seems to boost elimination of the extra fluids that cause the problem in CHF, but it doesn't always improve quality of life or toleration of exercise for these patients. L-arginine seems to improve quality of life, exercise tolerance and effectiveness of nitroglycerin therapy as well as decrease symptoms for patients with angina, but doesn't seem to decrease the actual disease. In a 2006 study in the Journal of the American Medical Association, L-arginine supplements did not improve vascular stiffness after myocardial infarction, and the study was discontinued after 8.6 percent of patients given L-arginine died while none in the control group died. Researchers concluded L-arginine should not be given to patients who have had acute myocardial infarction.

Sexual Dysfunction

• A dose of five grams per day might be effective in treating male erectile dysfunction because the erectile process requires nitric oxide synthesized by L-arginine, but a 1999 clinical trial testing a lower dose in humans showed no difference between L-arginine and a placebo. There is insufficient evidence that L-arginine might improve female sexual dysfunction.

Diabetes

• A 2001 study showed that lean patients with Type 2 diabetes had improved insulin sensitivity and decreased systolic blood pressure when taking 9 grams of L-arginine daily for a month. No changes were shown in hemoglobin, weight, diastolic blood pressure, serum potassium or heart rate. A study published in the June 13, 2006 American Journal of Physiology showed that the addition of 8.3 g L-arginine per day increased the effectiveness of a low calorie diet and exercise program for obese Type 2 diabetics. Topical application of L-arginine to the feet seems to improve circulation in diabetics, which might help prevent foot ulcers. But injecting L-arginine under the skin near an ulcer doesn't seem to shorten healing time or reduce the chance of later amputation.

Healing

• Taking L-arginine with eicosapentaenoic acid (EPA) and ribonucleic acid (RNA) before or after surgery seems to help shorten recovery time, ward off infections and improve wound healing. HIV-negative tuberculosis patients showed higher sputum conversion rates, increased weight gain and faster reduction of symptoms such as cough in a 2002 study, but HIV-positive patients in the same study showed no such results. L-arginine seems to help with healing of bone, burns, tendons, wounds and the gastrointestinal tract.

HIV and AIDS

• A 2000 study published in the Journal of Parenteral and Enteral Nutrition showed that L-arginine combined with hydroxymethylbutyrate (HMB) and glutamine and given orally as a dietary supplement slowed muscle wasting and improved lean body mass and immunity in HIV and AIDS patients.

Premature Infants

• Studies have shown L-arginine reduces the risk of severe and damaging inflammation of the digestive tracts of premature infants. Nitric oxide is produced in the intestines to protect the digestive system from inflammation, but very low birth weight and preterm babies who develop the inflammation are reported to have low concentrations of arginine.

Interactions and Adverse Effects

• L-arginine interacts with prescriptions to reduce blood pressure and increase blood flow to the heart. Since L-arginine and Sildenafil (Viagra) can both reduce blood pressure, caution should be used in combining them. Oral use of L-arginine has sometimes resulted in nausea and diarrhea. Although solid evidence is lacking, it is believed L-arginine can worsen sickle cell crisis and induce the outbreak of herpes symptoms. Intravenous administration of high dosage L-arginine has caused metabolic acidosis. Nitric oxide in high concentration is considered toxic to brain tissue.