Arginine hydrochloride is synthetically derived from an essential amino acid known as L-Arginine. It is mostly used to detect the deficiency of growth hormone in patients with conditions such as craniopharyngioma, chromophobe adenoma, hypophysectomy, panhypopituitarism, pituitary dwarfism, pituitary trauma, as well as other problems affecting growth and stature. The drug has also successfully been used to evaluate the function of the pituitary gland and its processes in acromegaly and gigantism. The injection is also used in the treatment of patients suffering from urea disorders, specifically, high concentrations of ammonia.
The drug is also available in tablet form, which is mostly used as a nutritional supplement to specifically improve the capacity of exercise in patients suffering from stable angina pectoris. The arginine injection originally received FDA’s approval in February 1973.
In summary, L-Arginine HCl is a prescription medicine that is commonly prescribed for a number of ailments and deficiencies. It is used in:
In patients whose pituitary function is normal, arginine is usually known to stimulate the release of the growth hormone from the pituitary gland. For patients whose pituitary function is impaired, there is usually lower or no increase in plasma growth hormone concentrations upon the administration of arginine.
Following the breakdown of proteins, the concentrations of glutamine and ammonia in blood are kept low by the urea cycle. However, some people may suffer from urea cycle disorders such as hyperammonemia, where there is a deficiency of one of more enzymes and/or cofactors crucial to the urea cycle. Arginine plays a role as an essential amino acid in such a case when one of the crucial enzymes/cofactors is deficient. L-Arginine HCl thus lowers the concentrations of ammonia and glutamine in the blood.
Due to its high chloride content and the fact that it is a precursor for HCl, arginine makes a great alternative treatment for metabolic alkalosis.
Since it is also a good precursor for nitric acid, it makes a crucial vasodilator and aids in the treatment of cardiovascular disease such as atherosclerosis.
The two main administration routes of arginine are oral and intravenous (IV). The recommended dosage depends on the application, the route of administration, as well as the age and weight of the patient.
For children, the overdose of L-Arginine HCl can be fatal. Hyperchloremic metabolic acidosis may also result as a side effect in pediatric patients where high doses are administered. Such patients may also experience cerebral edema or even death from an overdose of L-arginine HCl.
Animal models have shown no evidence of the drug’s possibility of harming the fetus during pregnancy. However, there is little information available on controlled studies regarding the injection of the drug and its side effects on pregnant women. Nevertheless, animal reproductive and drug response studies may not always yield the same results as human case studies. For this reason, the manufacturer of L-arginine HCl injections recommends that the drug is not to be prescribed for pregnant women.
There is also a possibility the drug causing adverse side effects if administered in high doses for patients with renal and hepatic impairment. For such patients, extreme caution should be taken before administration with arginine
Caution should also be taken when administering the drug to breastfeeding mothers as systemic arginine (as an amino acid) could be secreted in human milk, even though there is no evidence that arginine can be secreted through the mammary glands and subject the infant to drug exposure.
Another possible side effect that was seen in the drug’s clinical trials include maculopapular rash, which was observed by one patient and exhibited swelling and reddening of the hands and the face. Upon termination of the infusion, and the administration of 50mg diphenhydramine, the rash subsided. Hypersensitivity reactions such as anaphylaxis have also been reported during the drug’s post-market surveillance.
Also, about 3% of the patients experienced nausea and vomiting during arginine injection clinical trials. 3% of the patients also exhibited Flushing and headache side effects during clinical trials, which was mostly as a result of excessive infusion rates. Decreasing the infusion rate was seen to subdue these adverse effects. A single patient also exhibited thrombocytopenia during the clinical trials of arginine injection. An overdose of arginine injection may also lead to metabolic acidosis and hyperventilation. Approximately another 3% of patients were reported to have experienced extraversion while another 3% were also reported to experience paresthesia during the arginine injection clinical trials.
Other possible but rare side effects of arginine HCl may include hematuria, vasodilation, and hypotension.