L-lysine is an essential amino acid and is one of the key building block of muscle tissue. Human body is not able to synthesize lysine hence it needs to be acquired through diet or pharmaceutical supplementation. The recommended uptake of lysine in adults for regular biological functions are reported in the range of 12 to 45 mg·kg−1·d−1. Besides being essential for regular growth, this important amino acid participates in various vital biological processes like proteinogenesis, crosslinking of collagen polypeptides, uptake of essential mineral nutrients, and in the production of carnitine.D. Tomé and C. Bos, “Lysine Requirement through the Human Life Cycle,” J. Nutr., vol. 137, no. 6, pp. 1642S-1645S, Jun. 2007.E. Volpi, A. A. Ferrando, C. W. Yeckel, K. D. Tipton, and R. R. Wolfe, “Exogenous amino acids stimulate net muscle protein synthesis in the elderly.,” J. Clin. Invest., vol. 101, no. 9, pp. 2000–2007, May 1998. Carnitine is established to play a crucial role in energy production by transporting long-chain fatty acids into the mitochondria and generated toxic compounds out from the cell.
A few conflicting studies also suggest its role for enhancement of athletic performance. Some patented preparations to increase growth hormone in the body and for stimulating overall growth, cell repair and regeneration also used L-lysine HCl as a major component.S. H. Kim, Y. kyung Chung, J. Y. Chang, S. K. Lee, M. S. Lee, and S. K. Park, “Stable liquid formulation of human growth hormone,” US8409586B2. Lysine is also been recognised as an important precursor for glutamate synthesis, which works as a neurotransmitter in the vertebrate nervous system.F. Papes, M. J. Surpili, F. Langone, J. R. Trigo, and P. Arruda, “The essential amino acid lysine acts as precursor of glutamate in the mammalian central nervous system,” FEBS Lett., vol. 488, no. 1–2, pp. 34–38, Jan. 2001.
L-lysine HCl can improve calcium absorption as well as improvise collagen quality and muscle well-being in general, and has helped patients suffering from osteoporosis. It contributes to a positive calcium balance by boosting intestinal calcium absorption and improving the renal conservation of the absorbed calcium.R. Civitelli, D. T. Villareal, D. Agnusdei, P. Nardi, L. V Avioli, and C. Gennari, “Dietary L-lysine and calcium metabolism in humans.,” Nutrition, vol. 8, no. 6, pp. 400–5. L-lysine HCl has also been suggested to be used in combination with minocycline hydrochloride, and metronidazole to treat reactive arthritis or bursitis.E. L. J. Bonner and R. Hines, “Method for treatment of reactive arthritis or bursitis,” US6765000B2, 2004. With common occurrence in young men and women, this disease can be caused by species of Shigella bacteria, species of Salmonella, genitourinary pathogens, Chlamydia trachomatis, Neisseria gonorrhea, Ureaplasma urealyticum, Streptococcus pyogenes etc.
According to a few research and patented concepts, L-lysine HCl alone or with other active pharma ingredients can be used to treat Herpes simplex I and II infections which are viral by origin.K. Gerzon, “Herpes treatment,” US4415590A, 1983.
Usage of L-lysine HCl independently as well as in compounded form has been reported for nephroprotection when radioactive therapy is conducted especially against cancer. The proximal tubular uptake of radionuclide in the renal pathway is inhibited temporarily due to intravenous infusion of concomitant amino acid like lysine protecting the kidney from the radio toxicity.M. Singh et al., “Medicinal Uses of L-Lysine: Past and Future,” Int. J. Res. Pharm. Sci., vol. 2, pp. 637–642, 2011.
Treatment with L-lysine HCl has also been reported to be well tolerated and showed a significant decrease in positive symptoms of schizophrenia.C. Wass et al., “L-lysine as adjunctive treatment in patients with schizophrenia: a single-blinded, randomized, cross-over pilot study.,” BMC Med., vol. 9, p. 40, Apr. 2011.
Results have shown that administration by ingestion, especially with food, have much higher safety and lower possibility of adverse effects compared to injections.N. W. Flodin, “The metabolic roles, pharmacology, and toxicology of lysine.,” J. Am. Coll. Nutr., vol. 16, no. 1, pp. 7–21, Feb. 1997.
L-lysine is broken down in the liver and its supplementation needs an increased elimination of nitrogen from the body. Also, it is known to interference with urea cycle. Patients with impaired hepatic functionality or sensitivity to increase in blood ammonia concentrations are contraindicated for lysine.N. W. Flodin, “The metabolic roles, pharmacology, and toxicology of lysine.,” J. Am. Coll. Nutr., vol. 16, no. 1, pp. 7–21, Feb. 1997.
Amino acids are generally recommended during pregnancy as per individual requirement. Study on amino acids requirement during pregnancy has suggested increased requirement of essential amino acids during advanced stage of pregnancy. R. Elango and R. O. Ball, “Protein and Amino Acid Requirements during Pregnancy,” Adv. Nutr. An Int. Rev. J., vol. 7, no. 4, pp. 839S-844S, Jul. 2016. In a study lysine requirement in healthy pregnant women was determined to be 36.6 mg · kg−1 · d−1 during early stage and 50.3 mg · kg−1 · d−1 during advance stages of gestation.M. Payne, T. Stephens, K. Lim, R. O. Ball, P. B. Pencharz, and R. Elango, “Lysine Requirements of Healthy Pregnant Women are Higher During Late Stages of Gestation Compared to Early Gestation,” J. Nutr., vol. 148, no. 1, pp. 94–99, Jan. 2018.
There is no evidence indicating ill effect from lysine supplementation during breastfeeding. No specific safety data for L-lysine hydrochloride infusion could be identified. Physician’s advice before use is recommended.
L-lysine HCl may have a nephrotoxic effect and should not be taken with aminoglycoside antibiotics due to the increased risk of nephrotoxicity. L. Bumpstead, “Long-term use of supplemental lysine – is it safe?,” J. Aust. Tradit. Soc., vol. 19, no. 4, pp. 228–231, 2013. L-lysine HCl in large doses can be nephrotoxic and single large doses of aminoglycosides alone are nephrotoxic. When the two are combined, the toxicity was found to be additive.
L-lysine HCl interacts with calcium supplementation. It enhances calcium absorption; hence the prescribed doses need to be revised accordingly.
L-lysine hydrochloride has been proved to be safe as per most clinical studies with only mild side effects. No side effects necessitating the discontinuance of the drug were found during literature survey. However, most of the data available is for oral administration with limited data on injection route. In children between the age of 10-14 years, no serious adverse effect was noted when 14–22 g of L-lysine hydrochloride was infused intravenously to study its effect on urea cycle.T. Kato, M. Sano, and N. Mizutani, “Inhibitory effect of intravenous lysine infusion on urea cycle metabolism,” Eur. J. Pediatr., vol. 146, no. 1, pp. 56–58, Jan. 1987. Patients with cardiovascular or gall bladder disease should exercise caution in supplementation of lysine. Its long-term use can cause arginine deficiency.V. J. Mailoo and S. Rampes, “Lysine for Herpes Simplex Prophylaxis: A Review of the Evidence.,” Integr. Med. (Encinitas)., vol. 16, no. 3, pp. 42–46, Jun. 2017.
Studies with oral supplementation of lysine showed no significant adverse effects except upset stomach in some cases. Animal studies have shown that more than 3% oral ingestion of lysine lead to accumulation of triglycerides in liver.P. J. Garlick, “The Nature of Human Hazards Associated with Excessive Intake of Amino Acids,” J. Nutr., vol. 134, no. 6, pp. 1633S-1639S, Oct. 2004.
Other side effects of lysine supplementation may include headache, neutropenia, elevated liver enzymes, nausea, abdominal pain, and malaise. Warnings for antiviral drugs containing L-lysine hydrochloride API, generally include hypersensitivity, thrombolic thrombocytopenia purpura, hemolytic uremic syndrome, acute renal failure, and central nervous system involvement.
Store this medication at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond-use date. Do not flush unused medications or pour down a sink or drain.
