Frequently asked questions

How does Hepa-Merz work?

Hepa-Merz increases the detoxification capacity of the liver for the neurotoxin ammonia and lowers pathologically elevated ammonia levels. At the same time, an improvement in the mental state in patients with hepatic encephalopathy results.

Please also read:
Hepa-Merz Clinical Trials

How can the ammonia lowering effect of Hepa-Merz be explained?

A significant lost of liver function results with diseases of the liver (e.g., liver cirrhosis). This not only affects the synthesis of important endogenous substances, but the detoxification of neurotoxic metabolic preparations in particular. Notably, due to the disordered urea and glutamine synthesis, the neurotoxin ammonia can reach the systemic circulation before it has been detoxified and lead to disorders in brain function which are also summarized under the term “hepatic encephalopathy”. L-ornithine-L-aspartate is capable of promoting the detoxification of ammonia by stimulation of urea and glutamine synthesis.

Urea synthesis

Urea synthesis takes place in the periportal hepatocytes. The enzymes necessary for this process, carbamoyl phosphate synthetase and ornithine carbamoyltransferase are activated by the provision of L-ornithine-L-aspartate. At the same time, ornithine serves as starting material for urea synthesis and is consequently involved in a number of ways in the activation of the urea cycle and thereby in the ultimate ammonia detoxification. Approximately one-third of the ammonia is ultimately detoxified by urea synthesis in healthy individuals because urea represents the final form of excretion for ammonia.

Glutamine synthesis

Glutamine synthesis is localized to the perivenous hepatocytes, also called scavenger cells. These scavenger cells possess the enzyme glutamine synthetase which exhibits a high affinity to ammonia and converts glutamate into nontoxic glutamine by coupling with ammonia. 
L-ornithine-L-aspartate supplies starting material for the synthesis of glutamine to the perivenous cells by providing aspartate and ornithine after their conversion into dicarboxylate. The glutamine formed is not only a nontoxic form of transport for ammonia, but also necessary at the same time for the activation of the urea cycle. Aspartate and dicarboxylate act as activators for disordered glutamine synthesis in persons with cirrhotic livers.

Please also read:
Mechanism of action of Hepa-Merz

What carrier solutions are compatible with Hepa Merz® infusion solution concentrate?

The following carrier solutions are suitable:

Secondary infusion

Glucose 5 %: a / b / c
Glucose 10 %: a / b / c
Sterofundin: a / b / c
Tutofusin: a / b / c
Ringer’s solution: a / b / c
Isotonic NaCl: a / b / c
Aminosteril N-Hepa: a / b / c
Comafusin Hepar: a / b / c

For compatibility testing, six ampules of Hepa-Merz infusion solution concentrate were mixed with 450 ml of a carrier solution. The following parameters were tested at the start and at 2h, 5h and 24 h:

  • a) Color, appearance, pH, toxicity unchanged
  • b) No significant change in amino acid content (ornithine, aspartates); no significant formation of a degradation product (ornithine lactam) – tested using thin layer chromatography.
  • c) Compatibility with regard to the active substance from Hepa-Merz

What should be taken into consideration with the dosing of Hepa-Merz infusion concentrate?

Hepa-Merz infusion concentrate is indicated for the treatment of concomitant diseases and sequelae conditions due to disordered detoxification capacity of the liver (e.g., liver cirrhosis) with the symptoms of latent and manifest hepatic encephalopathy, particularly for the treatment of incipient consciousness disorders (precoma) or clouding of consciousness (coma). Up to 4 ampules per day are given as long as not indicated otherwise. Up to 8 ampules within 24 hours for incipient consciousness disorder (precoma) and clouding of consciousness (coma), depending on the severity of the condition.

Prior to use, the ampules are added to an infusion solution and infused in this form. Hepa-Merz Infusion concentrate is easily miscible with the standard infusion bases. However, due to vein tolerability, not more than six ampules should be dissolved per 500 ml infusion.

The infusion speed is a maximum of 5 g ornithine-aspartate (equivalent to the content of one ampule) per hour.

What must be taken into consideration with Hepa-Merz treatment in patients with liver disease and impaired renal function?

Severe renal insufficiency (reference value: serum creatinine value > 3 mg/100 ml) is considered to be a contraindication.

What options are there for recognizing subclinical HE?

Of the large number of test procedures used for the diagnosis of hepatic encephalopathy, the psychometric tests in particular, such as number connection tests, the line tracing test and the digit symbol test have emerged as sensitive and simple to perform tests for the recognition of HE. Also easy to perform is a writing sample with which the psychomotor skills are tested.

Please also read:
Psychometric test procedures